JPS5843118A - Wire extension wheel of automatic tension control type - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to an automatic tension control type railway rolling stock.

A wire rolling car is used to feed out electric wires (including wires, ropes, etc.) from a drum during overhead construction work, etc. It is located after the drum mount and has sufficient capacity to handle the pulling force of the winch. It provides a strong braking force (reaction force) and allows the wire to be fed out while maintaining the required wire tension. In view of the fact that this type of line rolling car is required to have constant tension characteristics rather than the constant speed characteristics of a winch, the applicant has previously developed a line drawing car that is capable of constant tension control. In other words, maintaining a constant tension means that the speed is not controlled, or even theoretically cannot be controlled. In other words, for example, if the wire is pulled only below the set tension, the control system of the wire rolling car will function to increase the braking of the wire in order to maintain a constant tension. Line speed l shows a tendency to slow down, and in extreme cases, for example, if the protector (wire connection) gets caught on the wire wheel and the wire extension stops, the traction force from the winch side cannot reach from the wire wheel to the wire rolling wheel. The electric wires in some areas were loosened, and the line extension cars had to stop moving accordingly. This trend is good as it is consistent with the wire extension work as a whole.

However, regardless of the speed, constant tension control is required; in principle, when the actual tension is less than the set tension, the speed will decrease forever, and when it is greater than the set tension, the speed will increase forever. However, if this speed change occurs too rapidly, an unfavorable situation may arise. In other words, in actual wire extension work, various equipment such as a drum frame, a wire extension car, a metal wheel, etc. are arranged at each part of the wire extension, but the existence of each of these equipment is Therefore, since there is a time delay in the transmission of tension and speed, a sudden change in the payout speed may actually cause overtension or slack in each extended line section. For example, if the payout speed suddenly slows down, the braking of the drum mount in the previous stage cannot cope with this due to inertia, making it impossible to apply the required back tension to the electric wire at the entry side of the railcar. In addition, if the feeding speed suddenly increases, excessive force is applied to the metal wheel and other equipment, and it is also dangerous.

This invention was made in view of the above circumstances, and the invention is based on the control system K, which controls the time change in wire speed, that is, the element of acceleration.
The purpose of this is to prevent sudden changes in the wire speed by controlling the edge M'l:□ to maintain a constant speed while assuming a constant tension, thereby eliminating the above-mentioned disadvantage.

The present invention will be explained below based on illustrated embodiments.

First, to explain the configuration of this rolling train 1, 2 is a shoe chain drum, 3 is an electromagnetic retarder for braking, and the braking torque is transmitted to the shaft 2a of the shoe chain drum 2 via a differential gear device 4. I'm going to do it. Electromagnetic retarder 3
Due to its nature, when the rotation of the rotor 3a becomes zero, the generated torque also becomes zero.In order to ensure the required torque by rotating the rotor 3a at a constant rate even when the wire drawing speed is zero, the induction motor 5 is The outer case 4a of the differential gear device 4 is kept rotating at all times.

6 is a one-way clutch for preventing reverse rotation.

The control system for keeping these mechanical systems at a constant wire tension includes a magnetic self that detects the extending force of the wire rolling car 1 via a shaft 21L, a detected tension signal from the magnetic self, and a tension setting 11.
An amplifier 9 that amplifies and inverts the difference from the reference signal of 8, and a power amplifier 10 that increases or decreases the excitation current to the electromagnetic retarder 3 in response to the output from the amplifier 9.
It mainly consists of The power amplifier 10 consists of a thyristor and its gate control circuit, and outputs a constant excitation current when the detected tension signal and the reference signal are equal and the output potential from the amplifier 9 is zero, and when the detected tension signal is greater than the reference signal. The circuit is set in advance so that control is performed to reduce this when the value is , and increase it when it is small. Here, the part indicated by the thick solid line in the figure corresponds to the sudden speed change prevention mechanism in this embodiment.

This sudden speed change prevention mechanism includes an output shaft 4b of the differential gear device 4.
A tacho generator 11 that generates a speed signal for unwinding the electric wire in a rotating state, an amplifier 12 that amplifies and controls the speed signal, and a differentiation circuit 13 that differentiates the output from this amplifier 12 are wired as shown in the figure. It is. Actually, however, this differentiating circuit 13ri is designed together with the amplifier 12 based on the theory of automatic control, taking into consideration the dead time elements, time delay elements, etc. of each device in the control system.

Next, the operation of this track rolling car 10 will be explained.

When feeding is performed with a predetermined tension, the detected tension signal from the MagneSelf and the reference signal from the tension setting device 8 are equal in absolute value, and the amplifier 9KH zero potential is input, and the output is also zero potential. . Therefore, the power amplifier 10 outputs a predetermined excitation current, and the electromagnetic retarder 3 continues to generate a predetermined braking torque. When the extending force increases, the detected tension signal from the magnet self exceeds the reference signal, and a ■ potential is applied to the amplifier 9, which is amplified and inverted, and an O potential is generated on the output side of the amplifier 9. This zero-minute potential reduces the excitation current of the power amplifier 10 by a considerable amount, which acts to relieve the braking at the electromagnetic retarder 3 and reduce the actual tension. When the extending force decreases, the detected tension signal becomes lower than the reference signal and the opposite effect is performed, so that as a result, this rolling car 1 always maintains a constant tension. In the above, when the feeding speed is constant, the sudden speed change prevention mechanism does not particularly work. This is because the action of the differentiating circuit 13 causes no change at point P in the figure.

When a change occurs in the feeding speed, the output of the amplifier 12 increases or decreases, and an output corresponding to the increasing or decreasing speed (that is, the acceleration of the feeding speed) is generated at point P. This output generates a ■ potential at the Hp point when the feeding speed increases, and an O potential when it decreases.As a result, the output of the amplifier 9 moves to the ■ side and the θ side, respectively. The excitation current to the electric a-retarder 3 which is the output of is increased or decreased. In other words, when the feeding speed tends to increase, the braking is strengthened to suppress it, and when it tends to slow down, the braking is weakened to promote feeding and suppress changes in speed. .

As is clear from the above, the sudden speed change prevention mechanism suppresses changes in speed, and unlike so-called constant speed control, constant tension control is aimed at and maintained as a whole. .

However, if the sudden speed change prevention mechanism is made too strong, the original constant tension control will be impaired, so the amplifier 12 should be adjusted with sufficient balance in mind.
It goes without saying that the characteristics of the differential circuit 13 and the time constant of the differentiating circuit 13 must be determined. FIG. 2 shows the relationship between the wire drawing speed and the wire drawing tension. In this embodiment, since a differential element is incorporated, the increase in tension is proportional to the gradient of the change in speed and exhibits nine characteristics. The broken line represents the characteristics not based on the present invention.

As explained above, according to the present invention, in an automatic tension control type wire rolling car that feeds out electric wire while controlling the feeding force at a constant level, a detection device for the wire feeding acceleration is incorporated to ensure that the acceleration is correct. By increasing the above constant tension when it is negative and decreasing it when it is negative, rounding suppresses the small speed fluctuations of the wire while maintaining the constant tension characteristics at various speeds.The red absorption absorbs red and reduces it when the speed changes. In some cases, this can be relaxed so that it does not occur rapidly, resulting in extremely stable wire drawing characteristics and improved safety.

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[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram of a wire rolling vehicle according to an embodiment of the present invention, and FIG. 2 is a characteristic diagram showing the relationship between wire drawing speed and wire drawing tension along the time axis. 1... Line car 11... Tacho generator 12... Amplifier 13... Differential circuit 1!1 diagram

Claims (1)

[Claims] In an automatic tension control type wire rolling vehicle that feeds out electric wire while controlling the feeding force to a constant value, a wire feeding acceleration detection device is incorporated, and when the acceleration is positive, the above-mentioned constant tension is set. An automatic tension control type rolling stock that increases the tension and decreases it when it is negative.