JPS6347043B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a loop rolling car, and more particularly to a loop rolling car intended for automatic tension control.

When constructing overhead power transmission lines, a so-called loop extension is sometimes performed in which the messenger wire connected to the end of the electric wire to be extended is turned back at the end point of the extension section. In principle, this loop wire extension method does not require any driving force under ideal friction-free conditions.
Based on this principle, it is used especially for wire extension work that requires high tension. Conventionally, as a loop wire rolling vehicle for carrying out this loop wire drawing method, one is known in which the shaft of a feeding capstan and the shaft of a winding capstan are connected via a differential gear device that allows the outer box to be freely driven. It is being

By the way, it is generally considered best to control the winding to have a constant speed characteristic and the feeding to have a constant tension characteristic when drawing an electric wire. For this reason, even in the loop wire extension method, the winding capstan winds the wire at a constant speed, and the feeding capstan drives the outer box of the differential gear so that the wire is fed out with constant tension braking. Although it is desirable to extend the wire while doing so, no satisfactory method has yet been found that can do this automatically.

In view of the above circumstances, the purpose of the present invention is to provide a loop rolling car that has high reliability, especially in terms of automatic tension control. In a loop wire rolling car in which the shaft of the capstan is connected to the outer box via a differential gear device that can drive the outer box, a tension detector detects the sending tension of the electric wire, and an output value from the tension detector. and a reference value set in advance corresponding to a predetermined tension, and a main loop having a power control unit that supplies a variable voltage according to the comparison result to a direct current motor that can freely control forward and reverse rotation and is provided for driving the outer box. , a speed detector that detects the rotational speed of the DC motor, a speed minor loop that adds the output value of the speed detector to the comparison result, and a current detector that detects the current of the DC motor; This output value is added to the comparison result through a current minor loop that adds the output value of the current detector to the comparison result, and an intermediate amplifier that operates only when a predetermined value or more is detected by the speed detector. The gist is to provide a speed upper limit loop for addition.

The details of these inventions will be explained below based on the illustrated embodiments.

FIG. 1 is an explanatory diagram showing an embodiment of the present invention.

First, the basic configuration of this loop extension car will be explained.

Reference numeral 1 denotes a shuttle drum serving as a feeding capstan, and the shaft 1a of the shuttle drum 1 can be slightly displaced in the horizontal direction in order to detect tension. 2 is a drum-shaped winding capstan. The shaft 1a of this shuttle drive drum 1
and the shaft 2a of the winding capstan 2 are connected via a differential gear 3, and a three-phase AC commutator motor 4 is connected to the shaft 2a of the winding capstan 2.
It is driven by. This differential gear device 3 has an outer box 3a
is rotatable, and the rotation ratio of the winding drum 1 to the take-up capstan 2 is changed by the rotation of the outer box 3a, and the predetermined feed-out tension T is maintained constant by changing the feed-out speed S. It is.

On the other hand, 5 is a magnet cell as a tension detector.
In response to the horizontal reaction force of the shaft 1a of the shift drum 1, a DC voltage proportional to the sending tension T is output as a tension signal. Incidentally, reference numeral 5a denotes a corrector which corrects the value detected by the magnet cell 5 with respect to the sending-out inclination of the electric wire, and extracts a more accurate electric wire tension signal. 6 is the power control section, Magnesel 5
(Specifically, the output value of the corrector 5a) is compared with a reference value set in advance to be equivalent to a predetermined tension _T1 in the tension setting device 6a, and the result of this comparison, specifically, is adjusted according to the difference. It has a function of supplying a variable voltage V to a direct current motor 7 which is provided for driving the outer box 3a of the differential gear device 3 and whose forward and reverse rotation can be freely controlled. In this embodiment, the thyristor power output section 6b is controlled through the thyristor gate control section 6c. That is,
This thyristor power output section 6b is connected to the DC motor 7
In addition to supplying a constant current to the field, the motor is equipped with a group of three-phase full-wave anti-parallel thyristors, and supplies a DC voltage V that is variable in forward and reverse directions to the armature 7a of the DC motor 7 according to a signal from the thyristor gate control section 6c. be. In the figure, A ₁ , A ₂ , and A ₃ are intermediate amplifiers.

Next, the operation of this basic configuration will be explained.

A three-phase alternating current commutator motor 4 drives at a predetermined speed a feed-out feed chain drum 1 and a winding capstan 2 via shafts 1a and 2a, respectively. In steady state, the delivery speed S is equal to the winding speed S'. When a change occurs in the feeding tension T, the feeding speed S is changed relative to the winding speed S' by rotation of the outer box 3a of the differential gear device 3, thereby absorbing the tension change. Automatic control for this purpose is performed as follows.

First, the operation related to the DC motor 7 will be explained. FIG. 2 shows the variable voltage V (which can be either positive or negative) of the thyristor power output section 6b is applied to the armature 7a of the DC motor 7 via the equivalent resistance R such as the internal resistance of the output section 6b and the internal resistance of the DC motor 7. Indicates the state where the is connected. A constant excitation current is passed through the field of the DC motor 7 from the thyristor power output section 6b, and the armature 7a receives a back electromotive force E (+ when rotating in the direction of the deceleration load) proportional to its rotation speed n.
In the opposite case -) occurs. Therefore, if the current flowing from the thyristor power output section 6b toward the armature 7a is I, then from Kirchhoff's second law, the relationship IR=VE is established. When transformed, I=V-E/R=V-Kn/R=V/R-K'n(A) K and K' become constants. Now, considering the variable voltage V as a parameter, this equation means that the current I is expressed by a linear equation related to the rotation speed n of the armature 7a. Figure 3 shows this relationship in a graph, where the horizontal axis is the rotation speed n of the armature 7a, the vertical axis is the current I, the slope of each straight line is -K', and the intercept is V/R. It is. The reason why each straight line is saturated parallel to the horizontal axis is to protect the DC motor 7.
Since the torque Tq of the DC motor 7 is proportional to the current I, and the sending tension T is proportional to this torque Tq, as a result, an increase or decrease in the current I corresponds to an increase or decrease in the sending tension T. In addition, amateur 7a
An increase or decrease in the rotational speed n corresponds to an increase or decrease in the delivery speed S. From Fig. 3, for example, when the applied voltage is +V and the rotation speed is n ₀ , the torque Tq (∝ wire stretching tension T) is zero (indicating no-load operation, I = 0); It can be seen that when n increases to _n1 , a braking force of torque Tq ( _T1 ) is generated.

Here, FIG. 3 will be briefly explained. The first quadrant is the forward rotation acceleration torque, which corresponds to the state in which the chain drum 1 is driven in the feeding direction when forcibly feeding the wire, and the fourth quadrant is the forward rotation regenerative torque, which corresponds to the state in which the chain drum 1 is driven in the feeding direction when the wire is forcibly fed out. The second and third quadrants correspond to a state in which braking force is applied to the drum 1 to maintain a predetermined wire tension, the second and third quadrants correspond to a state in which the wire is wound, and the third quadrant corresponding to the first quadrant corresponds to a state in which the wire is wound in a reverse direction. This is the acceleration torque, and the second quadrant corresponding to the fourth quadrant is the reverse regeneration torque. It is mainly the fourth quadrant that is directly related to this invention.

Now, the explanation will be given assuming that the intended sending tension is _T1 . When the rotational speed n (∝feeding speed S) is _n1 , the applied voltage V from the thyristor power output section 6b is stabilized at V. Here, when the sending tension T changes from T ₁ to T ₂ , the change is first detected by the magnet cell 5, returning to FIG. This detected value is output as a voltage, corrected to a more accurate value by the corrector 5a, and then input to the power control section 6. In the power control section 6, this input detection value is compared with a reference value set in advance to correspond to a predetermined delivery tension _T1 by the tension setting device 6a. Then, the _thyristor gate control unit ₆
An applied voltage greater than V is applied from the thyristor power output section 6b to the armature 7 of the DC motor 7 via c.
A is supplied to V, and it is balanced when it becomes large (Fig. 3). This series of actions ends up increasing the rotation speed of the armature 7a from n to _n2 when the feed tension T is about to increase from _T1 to _T2 , and the feed speed S _increases from _S1 to _S2 . increase,
This increased speed absorbs the increase in tension and maintains the delivery tension T at _T1 . That is, it is the amateur 7 that changes the variable voltage V that is the output of the thyristor power output section 6b.
The only purpose is to change the rotational speed n of a, that is, the delivery speed S, and in this way, a constant delivery tension _T1 is always maintained. Although we have explained the "direct current motor that can freely control forward and reverse rotation" with the most typical characteristics, today, motors with various characteristics (for example, constant output characteristics, etc.) have been developed, so The length of the line, the distance between each iron tower,
It is of course free to consider the required tension and the like and adopt a material having these characteristics as appropriate.

Next, both the speed and current minor loops will be explained.

The basic configuration for tension control is complete with just this, and its function is fully demonstrated under good wire drawing conditions.

However, when extending a line while winding through mountains and valleys, such as in a mountainous area, the frictional disturbance of the safe increases, and the slack in the wires and cables between the steel towers is likely to increase. Due to these adverse conditions, even if the constant tension property itself functions well, unnecessary repeated fluctuations in the drawing speed and other disadvantages may occur.

Therefore, in order to solve this problem, that is, to provide responsiveness and stability to various adverse conditions, it was decided to add a velocity minor loop and a current minor loop.

First, to explain the configuration, in Fig. 1, 11 is a tacho generator which is a speed detector that detects the rotation speed n of the DC motor 7, A ₅ is an amplifier that outputs the rate of change in the rotation speed as a voltage, and 12 is a DC motor. Electric motor 7
A voltage corresponding to a current value detected by a current transformer serving as a current detector that detects the input current I (=the above-mentioned current I) is outputted. Then, these tachogenerator 11, amplifier _A5 , and current transformer ₁₂ are connected as shown in _FIG . In the case of a speed minor loop, the detected speed change rate is input negatively; in the case of a current minor loop, the detected current (∝torque) change is input negatively), and the speed minor loop X and current minor loop Y are input negatively. It is something that forms. Note that 13 is a diode.

The actions of these two loops X and Y are as follows.

First, the effect of the velocity minor loop X will be explained.

The speed minor loop X is the rotation speed n (speed) of the DC motor 7 when the signal from the intermediate amplifier _A2 is constant.
It has the effect of maintaining the value corresponding to the value.
In other words, the speed minor loop X is such that when the rotational speed n of the DC motor 7 increases even slightly while the signal from the intermediate amplifier A ₂ is constant, the voltage from the amplifier A ₂ increases more than the voltage from the amplifier A ₅ according to the change. As a result, the output voltage from the thyristor power output section 6b decreases, and accordingly, the torque Tq tends to increase sharply (the braking force tends to increase sharply), and the rotational speed n is suppressed from increasing. be. For this reason, torque Tq (feeding tension T
Although the transient fluctuation of
This has the advantage that there is little variation in the speed (corresponding to the sending speed S). In this case as well, it goes without saying that the torque Tq will soon be restored to Tq ₁ (predetermined tension T ₁ ) due to the function of the main loop in the basic configuration.

On the other hand, the current minor loop Y is an intermediate amplifier
When the signal from _A2 is constant, it has the effect of keeping the input current I to the DC motor 7 at a value corresponding to it. In other words, the current minor loop Y is such that when the torque (∝current I) Tq of the DC motor 7 increases even slightly when the signal from the intermediate amplifier A ₂ is constant, the voltage from the amplifier A ₂ increases according to the increase. As a result, the output voltage from the thyristor power output section 6b increases, and accordingly, the rotation speed n tends to increase sharply, and the increase in torque (∝ current I) Tq is suppressed. For this reason, rotation speed n (equivalent to feed speed S)
Although the transient fluctuation of is relatively large, there is an advantage that the fluctuation of torque Tq (equivalent to sending tension T) is reduced. In this case as well, the torque Tq is soon restored to Tq ₁ (predetermined tension T ₁ ) by the control function of the main loop. In other words, the velocity minor loop X controls the sudden change in the feeding speed S (∝n), and the current minor loop Y controls the feeding tension T.
This means that sudden changes in (∝Tq) are suppressed.
I purposely used the word "sudden change" here because both minor loops X and Y are electrical feedbacks, so they are particularly suitable for sudden changes that cannot be handled by the control function of the main loop in the basic configuration. This is because it is useful in terms of responding accurately. It has been confirmed that because of this usefulness, good results can also be obtained in suppressing long-period repetitive fluctuations in the feeding speed S.

Next, the speed limit loop will be explained.

This speed limit loop is also based on the above-mentioned basic configuration and has been improved upon.

That is, as described above, the DC motor 7 is driven by a current represented by I=V/R-K'n. Here, the variable voltage V from the thyristor power output section 6b is such that, for example, the detected tension from the magnet cell 5 is a predetermined tension T ₁
As long as it is higher, the feed speed S can be theoretically changed to any extent in order to solve this problem by increasing it.

The purpose of the speed limit loop is to eliminate the negative effects resulting from this phenomenon.

The configuration incorporates a speed detector that detects the rotational speed of the DC motor and outputs it as a voltage, and the main loop is compared via an intermediate amplifier that operates only when the speed detector detects a predetermined value or higher. The result is added, that is, the speed change is input to the negative tape. In the embodiment shown in FIG. 1, the tacho generator 11 for the speed minor loop is also used as a speed detector for the speed limit loop. Since the tacho generator 11 generates a DC voltage proportional to the rotation speed n, the intermediate amplifier A ₄ is activated only when this voltage exceeds a predetermined value (for example, the voltage value output when the rotation speed n = 2400 rpm). .

As a result, under any conditions, the DC motor 7 will not rotate beyond a certain level.
Also, even if the DC motor 7 has sufficient durability, if it is driven indefinitely, it will originally become 1:
The difference between the sending speed S and the winding speed S', which should be 1, becomes unlimited and the entire loop may become unnecessarily slack or tense due to a temporary abnormality, but this speed-limiting loop In this case, even if the deviation from the predetermined tension _T1 is large, there is no difference between the feed speed S and the take-up speed S' beyond a certain level, and the tension is adjusted over time, so it is difficult to recover when the abnormality stops. The time is short, and as a result, unnecessary speed fluctuations are reduced accordingly.

As explained above, in the loop rolling car according to the present invention, the outer box of the differential gear device that mediates the sending capstan and the winding capstan can be freely driven by a DC motor, and the basic It is equipped with a main loop that controls tension fluctuations, a speed and current minor loop that handles sudden fluctuations, and a speed upper loop that sets the upper limit of rotation of the DC motor, making it an excellent constant for basic tension fluctuation factors. It has the advantage of being able to quickly and stably respond to sudden fluctuation factors as well as tension properties, and being able to maintain a predetermined tension and speed with high precision and stability even under various adverse conditions. As a result, accidents caused by sudden tension fluctuations or speed fluctuations can be avoided, contributing to even safer wire extension work.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention, FIG. 2 is an explanatory diagram of the operation of a DC motor, and FIG. 3 is an explanatory diagram of the operation of the present invention. DESCRIPTION OF SYMBOLS 1...Feeding capstan (sequential drum), 1a...Shaft, 2...Take-up capstan, 2a...Shaft, 3...Differential gear device, 3a...
Outer box, 5...Tension detector (Magnesel) 6...Power control unit, 7...DC motor, 11...Speed detector (tachogenerator), 12...Current detector (current transformer), I...DC Current flowing through the motor, V...variable voltage from the thyristor power output section, S...feeding speed, T...feeding tension, _T1 ...predetermined constant tension, n...armature rotation speed (S), X... ...Velocity minor loop, Y...Current minor loop.

Claims (1)

[Scope of Claims] 1. In a loop wire rolling vehicle in which the shaft of a feeding capstan and the shaft of a winding capstan are connected via a differential gear device that can freely drive an outer box, the feeding tension of the electric wire a tension detector that detects the tension, and a forward/reverse generator that compares the output value of the tension detector with a reference value set in advance to correspond to a predetermined tension, and applies a variable voltage according to the comparison result for driving the outer box. a main loop having a power control unit that supplies a DC motor whose rotation can be freely controlled; a speed minor loop having a speed detector that detects the number of rotations of the DC motor; and a speed minor loop that adds the output value of the speed detector to the comparison result. , a current minor loop that includes a current detector that detects the current of the DC motor and adds the output value of the current detector to the comparison result; and when the speed detector detects a predetermined value or more. A loop line rolling car characterized by comprising a speed upper limit loop that adds this output value to the comparison result via an intermediate amplifier that only operates.