JPH0335231B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for determining the slackness of the main rope of a cable crane.
This invention relates to a main rope adjustment device for a cable crane that is designed to maintain an appropriate value at all times.

When pouring concrete for a dam, the first
A cable crane running on a circular arc track 1 as shown in the figure is used as the main equipment. In order to increase the pouring efficiency, two concentric arc-type cable cranes are used, a first crane moving tower 2 and a second crane moving tower 3, which travel on one arc track 1. Sometimes.

In this case, the mobile tower 2 of one first crane
Since the main rope 5 is stretched between the first crane fixed tower 4 installed at the center of the circular arc track 1, even if the mobile tower 2 of the first crane runs on the circular arc track 1, The span of the cable 5 is constant and the slackness does not change. However, the mobile tower 3 of the other second crane is located at a position off the center of the arc of the arc track 1.
Since the main cable 7 is stretched between the unit fixed tower 6,
When the mobile tower 3 of the second crane travels on the circular arc track 1, the span of the main rope 7 changes by the deviation 9 between the circular arc track 1 and the circular arc 8 centered on the No. 2 fixed tower 6, and The laxity of 7 will change. If the slackness of the main rope 7 changes in this way while the crane is operating, work efficiency will decrease, and it may also be dangerous if workers are not always aware of changes in the slackness of the main rope 7 at each position where the mobile tower moves. Therefore, Japanese Patent Publication No. 37-17064 has been proposed in order to ensure that the slackness of the main rope remains constant even when the mobile tower moves.

However, the above-mentioned system has the disadvantage that it is a large-scale device with a complicated mechanical mechanism, and that errors occur in adjusting the slackness of the main rope when the running wheels slip, and these errors gradually accumulate.

The present invention aims to provide a main rope adjustment device for a cable crane that eliminates such drawbacks, and provides a concentric arc motion type main rope adjustment device in which a movable tower of a second crane shares the travel path of a movable tower of a first crane. In the cable crane, a sershin transmitter is decelerated and rotated by a mobile tower traveling driven wheel of the second crane, and the mobile tower travel position of the second crane is detected by being rotated by an electric signal from the sershin transmitter. a main rope take-up device that rotates a main rope take-up drum and adjusts the length of the main rope of the second crane in accordance with a signal from the position signal generator; and a main rope take-up device that adjusts the main rope length of the second crane; A cell sink receiver for accumulating the amount of slip, a reference point checking striker provided in the moving tower traveling path, and a reference point checking striker provided on the moving tower of the second crane and operated by the same. When the reference point check limit switch and the accumulated slip amount of the Sershin receiver exceed the allowable value and the reference point check limit switch is activated, the reference point check limit switch and the Sershin receiver are operated at the above position until the accumulated slip amount of the Sershin receiver becomes zero. The gist of the present invention is a main rope adjustment device for a cable crane, which is characterized by being equipped with a servo motor that rotates a signal generator.

Next, an embodiment of the present invention will be described with reference to FIG. 2. Of the traveling wheels of the mobile tower 2 of the second crane explained in FIG. , the celsyn oscillator 12 is rotated. The reduction ratio of the reduction gear 11 is the second
When the mobile tower 3 of the crane travels the entire travel range of the circular arc track 1, the rotation of the Sershin transmitter 12 is 1
It is designed to stay within the rotational range.

When the Sershin oscillator 12 rotates, it generates an electrical signal in accordance with the rotation, and this electrical signal is input to the Sershin receiver 14 through the Sershin receiver 13 . As a result, the Sershin receivers 13, 14
is rotated by the same amount as the amount of rotational deviation of the Sershin oscillator 12. The electrical signal from the Sershin transmitter 12 passes through the Sershin receiver 14, is amplified by an amplifier 15, is input to a servo motor 16, and is rotated by the servo motor 16 via a speed reducer 17 to a position signal generator 18.

The position signal generator 18 includes a large number of position detection cams 19a, 19b, 19c, . . . and corresponding position detection proximity switches 20a, 20b, 20.
c, ... and amplifiers 21a, 21b, 21c, ...
...is built-in.

On the other hand, as shown in Fig. 4, the arcuate trajectory 1 is divided into a number of sections A, B, C, D, E, F, G, and H to determine the position, and a reference point is set at an arbitrary position. A check striker 22 is installed. When the position signal generator 18 shown in FIG. 2 is rotated by the servo motor 16, the position detection proximity switches 20b, 20c, . . . are activated in sequence.
Electrical signals are sequentially input to the limit switch 23 for setting the take-up amount shown in FIG. The take-up motor 24 is activated by this electric signal.
The main rope winding drum 25 provided on the mobile tower 3 of the second crane is rotated. The limit switch 23 for setting the take-up amount is connected to the main rope winding drum 25 via a reducer 26, and the reduction ratio of the reducer 26 is such that the main rope winding drum 25
When it is rotated to wind up or unwind by a deviation of 9, the limit switch 2 for setting the take-up amount
It is set so that the rotation of No. 3 is within one rotation. Then, the main rope winding drum 25 is rotated by the take-up motor 24 by the amount set by the limit switch 23 for setting the take-up amount, and the main rope 7 is wound up or rewound.
The sag is kept constant.

When the traveling driven wheel 10 slips, the rotational position of the position signal generator 18 and the section A where the mobile tower 3 of the second crane is located on the arc track 1 are determined.
Since an error occurs in ~H, it is automatically adjusted by the mechanism described below.

A reference point check limit switch 27 is attached to the moving tower 3 of the second crane, as shown in FIG. Then, each time the mobile tower 3 of the second crane passes the installation point of the reference point check striker 22 (see FIG. 4) on the arcuate trajectory 1, the reference point check limit switch 27 is activated.
The reference point tick limit switch contact 27a in the automatic zero adjustment circuit 28 is closed.

On the other hand, a pair of position detection cam 19z and position detection proximity switch 20z in the position signal generator 18 are used for detecting wheel slip error. That is, even if the traveling driven wheel 10 slips, the sershin transmitter 12 rotates, and its electrical signal is input to the sershin receiver 14 and the servo motor 16, and the electric signal is input to the sershin receiver 14 and the servo motor 16.
As the wheels rotate, errors caused by slippage of the driven wheels 10 are accumulated. When this accumulated error exceeds the allowable value, a slip error excess signal 20 is sent from the slip error detection proximity switch 20z.
z′ is output.

Check the reference point while the slip error excess signal 20z' is being output.
When a is closed, the relay 29 is energized. The relay 29 has three contacts 29a, 29b, and 29c, which close simultaneously when the relay 29 is energized.

When the contact 29c closes, the brake release coil 31 of the zero adjustment Sershin receiver holding brake 30 is excited, the zero adjustment Sershin receiver holding brake 30 is released, and the rotation of the servo motor 32 is transmitted to the Sershin receiver 13 via the speed reducer 33. will be able to convey the message. At this time, contacts 29a and 29b are also closed,
An automatic zero adjustment circuit 28 is formed.

A sershin receiver 34 is connected between the contact 29a and the contact 29b. This celsyn receiver 34 is initially set so that the phase difference with the primary side is zero when there is no slip on the running driven wheels 10. When the driven wheel 10 slips, a phase difference occurs between the primary side and the secondary side of the celsyn receiver 34 by the deviation due to the slip. When contacts 29a and 29b close in this state,
A potential difference signal between the primary side and the secondary side of the Sershin receiver 34 is amplified by an amplifier 35 and input to the servo motor 32. As a result, the Sersyn receiver 13 is rotated by the servo motor 32 via the reducer 33 having an appropriate reduction ratio until the potential difference between the primary side and the secondary side of the Sersyn receiver 34 disappears, and the Sersyn receiver 13 is automatically rotated. Zero adjustment at the reference point is completed.

The present invention improves operating efficiency and safety because the operator does not have to visually check the slackness of the main rope while performing the work, and the device becomes more compact because there are fewer mechanical mechanisms.

Furthermore, even if the wheels slip or wear out, the movable tower position is accurately detected, and the main rope is reeled in and out in conjunction with this, making it safe.

[Brief explanation of drawings]

Fig. 1 is a plan view of a concentric arc-type cable crane, Fig. 2 is a system diagram of an embodiment of the present invention, Fig. 3 is a front view of the main rope take-up device, and Fig. 4 is a diagram of divisions in an arcuate track. It is an explanatory diagram. DESCRIPTION OF SYMBOLS 1...Circular track, 2...Moving tower of the first crane, 3...Moving tower of the second crane, 7...Main rope, 10...Travelling driven wheel, 11...Reducer, 12
...Selsin transmitter, 13, 14, 34...Selsin receiver, 16, 32...Servo motor, 18
... Position signal generator, 22 ... Striker for reference point check, 24 ... Take-up motor, 2
5... Main rope winding drum, 27... Reference point check limit switch.

Claims (1)

[Claims] 1. In a concentric arc moving cable crane in which a moving tower of a second crane shares the traveling path of a moving tower of a first crane, a sershin transmission is decelerated and rotated by a moving driven wheel of the moving tower of the second crane. a position signal generator that is rotated by an electric signal from the cell-syn transmitter and detects the traveling position of the mobile tower of the second crane; and a main rope winding drum according to the signal from the position signal generator. A main rope take-up device that rotates to adjust the length of the main rope of the second crane, a celsyn receiver that accumulates the amount of slip of the mobile tower traveling driven wheel, and a reference point check provided in the mobile tower travel path. a reference point check limit switch provided on the movable tower of the second crane and operated by the reference point check striker, and the cercin receiver when the amount of accumulated slip exceeds a permissible value and the and a servo motor that rotates the position signal generator until the amount of slip accumulated in the Sershin receiver becomes zero when a reference point check limit switch is activated. Device.