JPH11139757A - Gantry crane and its running control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform simple control whereby in a gantry crane, a leg span can be instantaneously changed in accordance with a kind of a conveyed object, it is moved properly along a specified conveying route of the crane at a reduced cost. SOLUTION: In one end of a girder 12, a fixed leg 14 is provided, in the other end, a movable leg 16 able to move along the girder is provided. Between the movable leg and the girder, by providing a moving jack, the movable leg is moved relating to the girder, a leg span can be changed. A gantry crane thus formed is made movable to run by a drive means 24 provided in both leg parts, as a guide tape specifying a moving route, a tape able to generate an eddy current is used, by a sensor detecting the tape eddy current by an eddy current applying means provided in a crane running part, guide running along the route is made possible. An output of the drive means can be adjusted by stages by an inverter. A pair of sensors are provided in a width direction, in the case that a pair of both the sensors are dislocated from a guide tape, control is advanced into direction correction control by output adjustment of the drive means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gantry crane and a travel control method thereof, and more particularly, to a gantry crane having a variable leg span and a travel control method thereof.

[0002]

2. Description of the Related Art A gantry crane is a bridge-type crane having legs at both ends of a girder as a horizontal girder. The gantry crane moves along a traveling rail or travels on a road surface by running a tire to transport a lifted object. What to do.

[0003]

In this type of gantry crane, a gantry crane is used in accordance with the size and weight of a conveyed object. The one that matches the object is selected. However, it is desirable that the leg span can be appropriately changed according to the situation at the site and that the transport path can be freely set, because it can be used for all purposes. Conventionally, the same crane is used even after the transfer of the largest-sized goods to the crane is completed, and the movement route is restricted as the construction progresses. There are many.

Further, in a conventional road surface traveling type gantry crane, a magnetic path is embedded in the traveling road surface to form a transfer path. However, it is difficult to detect a magnet and the material used is limited to a magnetic material. , It is necessary to take care not to add other magnetic factors when embedding the magnet.
It was not worth the cost.

SUMMARY OF THE INVENTION The first object of the present invention is to provide a gantry crane capable of immediately changing a leg span according to the type of a conveyed object, focusing on the above-mentioned conventional problems. A second object is to provide a traveling control method for a gantry crane that can be accurately moved along a prescribed transport path of a crane and that is inexpensive.

[0006]

To achieve the above object, a gantry crane according to the present invention has a fixed leg at one end of a girder and a movable leg movable along the girder at the other end. By providing a moving jack between the movable leg and the girder, the movable leg can be moved relative to the girder to change the leg span. In this case, the moving jack includes a screw rod detachably held at an arbitrary position of the girder, and a moving operation arm capable of being screwed forward and backward with respect to the screw rod and capable of engaging and disengaging the movable leg. And it is possible to change the position along the longitudinal direction of the girder.

In addition, the traveling control method of a gantry crane according to the present invention enables a gantry crane having a variable leg span to be movable and driven by driving means provided on both legs.
A tape capable of generating an eddy current is used as a guide tape for defining the moving path, and guide running along the path is enabled by a sensor that detects the tape eddy current by an eddy current applying means provided in the crane running unit, and the driving means Output adjustment is possible, the sensor is provided in a pair in the tape width direction, and when both sensors of the pair come off from the guide tape, the direction adjustment control is started by the output adjustment of the driving means. I have.

[0008]

According to the above construction, the leg span of the gantry crane mounts the moving jack at an appropriate position on the girder, and the tip of the operating arm, which is the moving portion of the jack, is engaged with the movable leg. The movable leg moves by rotating the screw rod, and the leg span can be changed. Since the leg span depends on the amount of rotation of the screw, the adjustment amount is optional,
Fine adjustment is possible. This operation can be easily performed by lifting the girder on the movable leg side. At this time, the movable amount can be smoothly changed by making the movable leg rotatable with respect to the girder, and the coarse movement to the required position in advance Then, fine adjustment may be made by rotating the screw rod.

Further, the crane moving route is formed by an eddy current generating tape, whereby the running route can be set at low cost, and the running route can be set and guided even on a horizontal road surface. . By forming this tape along the running surface on the fixed leg side, stable guide becomes possible, and readjustment of the running route is unnecessary even if the leg span is changed. In addition, since a pair of sensors for detecting the tape is used, and correction control is performed when both of the sensors come off the tape, it is possible to prevent frequent occurrence of a control operation to prevent processing from being performed, and to perform correction. Since the operation is also the output control of the driving means, there is an advantage that the adjustment can be easily performed.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of a gantry crane and a traveling control method according to the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a front view and a side view of a gantry crane according to an embodiment. This gantry crane 10
Has a fixed leg 14 at one end (right end in the front view) of a girder 12 constituting a horizontal beam, and a movable leg 16 at the other end. Each of the legs 14 and 16 has a configuration in which the legs are opened forward and backward, and bogie portions 18 and 20 are provided at lower ends thereof, and traveling wheels 22 are attached to a lower surface portion so as to be able to travel on a road surface. As shown representatively on the movable leg side in FIG. 1 (2), a drive motor 24 is disposed at one end of each of the bogie units 18 and 20, and the corresponding wheels 22 are used as drive wheels. It is designed to be runnable.

In such a configuration, in the gantry crane 10 according to the embodiment, the movable leg 16 is
The leg span can be arbitrarily adjusted by moving the leg span right and left along the line 2. An adjusting mechanism for this is shown in FIG. FIG. 2A shows the configuration of the upper end connecting portion of the movable leg 16 to the girder 12. As shown in the figure, the girder 12 has a configuration in which three H-shaped steels 12L, 12C, and 12R are arranged in parallel with a space therebetween, and an intermediate gap therebetween is filled with an H-shaped steel and a flat plate 26 to be integrated. An I-shaped steel 30 is disposed on the lower surface of the central H-shaped steel 12C, which serves as a traveling guide for a hoist 28 constituting a hoist.

The upper end structure of the movable leg 16 is configured so as to sandwich the girder 12 configured as described above from the left and right in FIG. 2A, and stands upright along the outer surface of the girder 12. The lower side plates 32 (32L, 32R) have lower side flanges of a pair of left and right H-shaped steel members 12L, 12R which form the girder 12, and support the girder load. Mold steel part 34 (34
L, 34R). At the upper position of the square steel part 34, the side plate 32 is further provided with a roller 36 that can roll on the upper surface of the lower flange of the pair of left and right H-shaped steels 12L and 12R of the girder 12. For this reason,
The movable leg 16 can be moved in a direction approaching or moving away from the fixed leg 14 by traveling by the roller 36 by raising the movable end of the girder 12.

On the other hand, it is necessary to stop and hold the movable leg 16 at an appropriate position where the movable leg 16 has moved. A plate 38 is arranged. The girder 12 is provided on the side plate 32 of the movable leg 16.
A flat plate portion 40 extending on the upper surface side of the moving portion and facing the positioning plate 38 on the movement path thereof, and position holding means 44 having a stopper bolt 42 which can be inserted into the stopper hole attached thereto. I have. Thus, after the movable leg 16 has moved to the span position as appropriate, the stopper bolt 42 is lowered, and the distal end is inserted into the stopper hole of the positioning plate 38, whereby the movable leg 16 can be held in position. In the embodiment, as shown in FIG. 2 (2), the fitting U-shaped body 48 which can be disengaged from the support 46 provided on the outer surface of the side plate 32 of the movable leg 16 can be easily attached and detached. It has a configuration.

Means for adjusting the position of the movable leg 16 is as follows.
In the embodiment, the movable jack 50 is used. The specific structure is shown in FIG. As shown in the figure, the moving jack 50 includes a screw rod 52 that is rotatably arranged at a fixed position on the girder 12 side, and a moving operation arm 54 that can move along the rod by rotating the rod 52. . The moving operation arm 54 is a flat plate bent in the shape of a crank, and has a nut portion 55 screwed to the rod 52 at one end and a post 56 attached to the back surface of the side plate 32 at the other end. A detachable fitting U-shaped body 58 is provided. Thereby, the screw rod 5
By rotating the nut 2, the nut portion 55 is advanced and retracted, and the fitting U-shaped body 58 is forcibly moved along the movable leg 16 along the longitudinal direction of the girder 12. Since the moving operation arm 54 is formed in a crank shape, the position of the movable leg 16 can be moved beyond the length of both ends of the screw rod 52.

By the way, the screw rod 52 may have a length extending over the entire length of the girder 12, but in the embodiment, a short length is used, and the span is adjusted while appropriately changing the installation position according to the position of the movable leg 16. I am trying to do it. For this reason, screw rotation support brackets 60 having U-shaped grooves formed along the side edges of the girder 12 are attached at regular intervals. After moving the movable leg 16 by rotating the screw rod 52 between the pair of brackets 60 and moving the screw rod 52 between the next brackets 60, the screw rod 52 is moved beyond the rod length. To adjust the span adjustment.

The span adjusting operation of the gantry crane 10 having such a leg span adjusting function will be described with reference to an operation example shown in FIG. FIG. 3 shows an example in which the movable leg 16 is moved and adjusted from left to right. With the fitting U-shaped body 58 of the operation arm 54 protruding to the left from the rod of the moving jack 50, the fitting U is fitted to the support 56 of the leg side plate 32, and the screw rod 52 is rotated. This may be performed using a ratchet wrench or the like. As a result, the nut portion 55 of the movement operation arm 54 is screwed rightward, and the movement proceeds sequentially (FIGS. 3A to 3C). Nut 55 is rod 5
After reaching the right end of No. 2, the screw rod 52 is inverted (FIG. 3D), and the rod 52 may be rotated so that the nut portion 55 further moves rightward from this state. Thereby, the movable leg 16 is moved to an arbitrary position along the girder 12, and the span distance with the fixed leg 14 can be adjusted arbitrarily. In the embodiment, the minimum adjustment amount is limited by the interval between the stopper holes of the positioning plate 38. However, for example, by using a mechanism in which the continuous groove is expanded at an appropriate position to have a stopping function, the mechanism can be stopped at an arbitrary position. It can be stopped. As a result, as shown in FIG. 4, the leg span of the gantry crane 10 is arbitrarily adjusted as shown in FIGS. You can do it. In this span adjustment, as shown in FIG. 4, while moving the hoist 28 or using a balance weight to balance the center of gravity, the movable leg 16 is particularly adjusted.
Do it by lifting the side.

The gantry crane 10 according to the embodiment is capable of self-running along a crane traveling line. In order to define the traveling line, a tape capable of generating an eddy current is used. In the embodiment, an aluminum tape 62 is used as shown in FIG.
Is laid along the running line. The crane traveling carriage 18 is provided with eddy current applying means (not shown), and the eddy current applying means uses an aluminum tape 62.
A sensor 64 for detecting an eddy current generated on the side is provided. The sensors 64 are arranged in pairs at intervals corresponding to the tape width of the aluminum tape 62. Accordingly, the gantry crane 10 travels while detecting the tape eddy current with the sensor 64, thereby detecting whether or not the gantry crane has deviated from the traveling line, and is capable of moving and traveling. As described above, the gantry crane 10 is provided with the drive motor 24 for self-traveling, and is provided on both the fixed leg 14 side and the movable leg 16 side. Both motors 24S, 2
The output of 4M can be adjusted by inverter control by a control device (not shown), but the embodiment is configured so that two-stage output adjustment of 100% output and 50% output can be performed stepwise. Then, the guide travel is enabled along the tape path by the sensor 64, and when both of the pair of sensors 64 are disengaged from the aluminum tape 62, the control device enters the direction correction control by adjusting the output of the drive motor 24. Like that.

The specific direction control will be described with reference to FIG. When a pair of sensors 64 is located in the tape 62 (FIG. 1A), the output of each drive motor 24 is 10
Keep running at 0% output. As shown in FIG. 2B, the traveling direction is slightly shifted, and one sensor 64 is attached to the tape 6.
2, but the other is still determined to be in the steady running state when it is still positioned on the tape 62. Then, as shown in FIG. 3C, when it is determined that any of the paired sensors 64 is out of the tape 62, the direction correction control is started. As the moving direction was deviated upward while moving forward, the motor on the fixed leg 14 side
The output of 00% is maintained, and the movable leg 16 side is adjusted to 50% output. As a result, the resultant direction of the velocity vector becomes a direction returning to the tape line direction, and the trajectory is corrected.

In the gantry crane 10 having the fixed leg 14 and the movable leg 16 and capable of adjusting the leg span, the control method as described above allows the traveling line to be a single traveling line on the fixed leg 14 side. And the travel line can be set very simply by the sensor 64 on the fixed leg 14 side. Further, since a pair of sensors are set in the width direction of the tape 62 and the direction correction control is performed when both the pair of sensors 64 are separated from the tape 62, the control operation becomes extremely simple, and the correction mode is not frequently entered. Therefore, stable crane traveling is possible.

As described above, by employing the gantry crane and the traveling control method according to the present embodiment,
It is possible to easily change the leg span by an arbitrary amount as required, and the traveling control of a gantry crane with a span adjustment function can be optimized by simple operation on the fixed leg side. Has become.

[0022]

As described above, according to the present invention,
A fixed leg is provided at one end of the girder, a movable leg movable along the girder is provided at the other end, and a movable jack is provided between the movable leg and the girder to move the movable leg relative to the girder. While making the structure that can change the leg span, such a gantry crane can be moved and run by driving means provided on both legs, using a tape that can generate eddy current as a guide tape that defines the movement path,
Guide running along the path is enabled by a sensor that detects the tape eddy current by the eddy current applying means provided in the crane running unit, and the output of the driving means is enabled,
Since a pair of the sensors are provided in the tape width direction, and when both of the pair of sensors come off the guide tape, the direction adjustment control is performed by adjusting the output of the driving unit,
The leg span can be immediately changed in accordance with the type of the conveyed object, and the effect of controlling the crane to accurately move along the specified conveyance path at low cost can be obtained.

[Brief description of the drawings]

FIG. 1 is a front view and a side view of a gantry crane according to an embodiment.

FIG. 2 is a sectional view of an assembled state of a movable leg and a girder, and an explanatory view of a movable jack.

FIG. 3 is an explanatory diagram of a leg span adjusting operation using a moving jack.

FIG. 4 is a front view of the gantry crane showing each mode after span adjustment.

FIG. 5 is a plan view showing a relationship between a tape arrangement for traveling control and a crane.

FIG. 6 is an explanatory diagram showing a relationship between traveling control and a sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Gantry crane 12 Girder 12L, 12C, 12R H-shaped steel 14 Fixed leg 16 Movable leg 18, 20 Bogie part 22 Wheel 24 Drive motor 26 Girder plate 28 Hoist 30 I-type steel 32 Side plate 34 Square steel part 36 Roller 38 Positioning plate 40 Plate Part 42 stopper bolt 44 position holding means 46 support 48 fitting U-shaped body 50 moving jack 52 screw rod 54 moving operation arm 55 nut part 56 support 58 fitting U-shaped body 60 rotation support bracket 62 aluminum tape 64 sensor

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Kazuyuki Tobita 537 Ue Hongo, Matsudo City, Chiba Prefecture Hitachi Plant Construction Machinery Engineering Co., Ltd.

Claims (3)

[Claims] 1. A fixed leg is provided at one end of a girder, and a movable leg movable along the girder is provided at the other end, and a movable jack is provided between the movable leg and the girder, thereby providing a girder. A gantry crane characterized in that a movable leg can be moved to change a leg span. 2. The moving jack has a screw rod detachably held at an arbitrary position on a girder, a moving operation arm capable of being advanced and retracted with respect to the screw rod and capable of engaging and disengaging with the movable leg. The gantry crane according to claim 1, wherein the gantry crane is configured to be movable along a longitudinal direction of the girder. 3. A gantry crane having a variable leg span can be moved and driven by drive means provided on both legs.
A tape capable of generating an eddy current is used as a guide tape for defining the moving path, and guide running along the path is enabled by a sensor that detects the tape eddy current by an eddy current applying means provided in the crane running unit, and the driving means Output adjustment is possible, the sensor is provided in a pair in the tape width direction, and when both sensors of the pair come off the guide tape, the direction adjustment control is started by the output adjustment of the driving means. Gantry crane traveling control method.