JPS6124526Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a tension characteristic variable type accumulator.

In a rewinding device such as a winder that manufactures sheet rolls by unwinding and rewinding a strip from a raw roll, or in a web coating/drying line, the central processing section is activated when the line is stopped on the unwinding or winding side. Accumulators are used to prevent shutdowns.

However, especially in coating and drying lines for strips, if the tension of the strip is large, such as when the line is stopped or started, the strip and the rolls may slip on the drive rolls before and after the accumulator. , scratches may occur on the coated surface or uneven coating may occur on the coater section. For this reason, it is necessary to suppress the tension fluctuation in the above-mentioned case as small as possible.

Conventionally, the tension fluctuations were detected by a tension detector and the accumulator (including the dancer roll) was raised and lowered using the signal from the PI regulator to absorb the tension fluctuations, but this was not sufficient. .

As a result of various studies on an elevator-type accumulator that adjusts tension by raising and lowering it, the present inventors found that stopping and starting a strip and tension fluctuations are
It turns out that there is a relationship as shown in Figures A and B. In other words, when the accumulator starts, stops, or decelerates on the inlet and outlet sides, the conveyance speed of the strip material changes, and if the conveyance speed difference changes positive or negative by more than a predetermined value, then, This results in sharp tension fluctuations. Conventionally, when tension fluctuations occur, this is controlled by PI control (proportional/integral control) to deal with the tension fluctuations, but this method cannot adequately respond to sudden tension fluctuations. It was hot.

The present invention was developed in view of the above points, and is based on changes in conveyance speed of strips, webs, and other belt-like objects on the inlet and outlet sides of the accumulator, and predicts sudden tension fluctuations that will occur next. The multor is immediately activated by a correction signal to minimize tension fluctuations as shown in FIG. 1C.

Next, the present invention will be explained with reference to the drawings which are one embodiment.

The drawings show the present invention applied to an elevator type accumulator in which the lower carriage moves up and down, FIG. 2 is an overall perspective view, and FIG. 3 is an explanatory diagram showing the control system.

In the figure, reference numeral 2 denotes a fixed guide roll that is rotatably provided at predetermined intervals on a support frame (not shown), and 3 is a carriage that has a movable roll 4 that is arranged half a pitch apart from the fixed guide roll 2. It is guided by the frame and installed so that it can be raised and lowered. Further, an idler sprocket 5 is provided at the upper part of the support frame, and a drive sprocket 6 is provided at the lower part, and one end of a chain 7 as a lifting means stretched between both sprockets 5 and 6 is attached to the upper surface of the carriage 3 and the lower surface thereof. The other end of the chain 7 is fixed to the chain 7 via a chain tensioning spring 8, and the chain tensioning spring 8 absorbs elongation of the chain 7 due to changes over time. In addition, 9 is a fixed weight for web tension adjustment, and the strip W is wound alternately around the fixed guide roll 2 and the movable guide roll 4.

Reference numeral 10 denotes an AC geared motor with a cyclo reducer, and its output shaft 11 is connected to a sprocket drive shaft 15 via a cam clutch 12, a transmission shaft 13, and a gearbox 14. Normally, it idles due to forward rotation, and the clutch 12 When this occurs, the carriage 3 is lowered at a constant speed.

Further, the rotation of the AC geared motor 10 is controlled by a known powder brake 16 that controls the drive shaft 15.
is transmitted through the chain 20.
This powder brake 16 consists of a rotor 17 that rotates at a constant speed with a chain 20, a stator 18 attached to a drive shaft 15, and an electromagnetic coil 19 (third
(see figure), the magnetic powder loaded in the opposing gap between the rotor 17 and stator 18 is excited in proportion to the excitation current applied to the electromagnetic coil 19, and a brake torque proportional to the excitation current is applied to the sprocket drive shaft 15. It is given to

The cam clutch 12 has the configuration shown in FIG. 4, and can rotate integrally or relative to the forward rotation direction of the AC geared motor output shaft 11 (cam 12a), but is always integrally rotated in the reverse rotation direction. It is supposed to rotate. Note that 12b is a ball.

The AC geared motor 10 rotates in a direction to lower the carriage 3 during normal conveyance of the web W, and its rotational speed is set to
The speed is higher than the upward speed of the carriage when it stops at the line entry side.

Reference numeral 21 indicates an inlet web drive roll of the accumulator 1, and 22 indicates an outlet web drive roll. The belt-shaped material conveyance speeds V ₁ and V ₂ of each roll 21 and 22 are detected by tacho generators 23 and 24, and the speed difference is detected by tacho generators 23 and 24.
V ₁ - V ₂ are compared by the comparator 25, and when the speed difference is larger than a predetermined value (normal fluctuation value) and the sign changes, that is, when the input side (or output side) stops, the activation is started. It is predicted that when the tension changes, or when the speed is decelerated, that a sharp tension change will occur next, and a corresponding correction signal is applied to the regulator 26. On the other hand, the actual web tension from the tension detector 27 is compared with the setting of the tension setter 28 and the PI regulator 29
A correction signal from the controller 26 is constantly applied to the regulator 26. An excitation current corresponding to the composite signal of both signals flows from the regulator 26 to the electromagnetic coil 19 of the powder brake 16.

Additionally, 30 is a carriage position detector which detects the upper and lower limit positions of the carriage 3 by movement of the chain 7 and increases or decreases the speed of the inlet drive roll 21 of the accumulator 1.

Next, the accumulator 1 having the above configuration
The control method will be explained.

First, when feeding the strip W to each roll 2, 4 or during maintenance, the powder brake 16
is turned OFF and the AC geared motor 10 is rotated forward or reverse to move the carriage 3 to the lowest or highest position.

Also, during normal operation, the drive rolls 21, 22
Since there is almost no speed difference between the two, the comparator 25 does not operate. However, the tension of the strip varies slightly due to the rotational resistance of the guide rolls 2 and 4, the inertia of the weight 9, and the like. In this case, the tension signal from the tension detector 27 is compared with the setting value of the setting device 28, and based on the correction signal from the PI regulator 29, the electromagnetic coil 1
Powder brake 16 by changing the excitation current to 9
Adjust the brake force. That is, when the tension of the strip becomes smaller than the set tension, the excitation current increases, and the driving force of the AC geared motor 10 (in the downward direction of the carriage) is applied to the drive shaft 15 to increase the tension. In the opposite case, the braking force is reduced to control the lowering of the carriage 3, thereby reducing the tension of the strip. Furthermore, the strip W
When the tension detector 27 is disconnected, the tension detection signal from the tension detector 27 becomes zero, and as is clear from the above, the cam clutch 12 engages and the carriage 3 descends at a predetermined speed, so the dead weight of the carriage 3 decreases. A rapid fall (damage to the carriage) due to this will be prevented.

Next, for example, when the inlet side stops, starts, or decelerates, the inlet side speed V ₁ changes. and,
When the value of V ₁ −V ₂ changes to either positive or negative, a large correction signal is superimposed on the correction signal from the PI regulator 29 by the signal from the comparator 25, and based on this, the excitation current is changed. Changes greatly.

That is, as shown in FIG. 1C, when the entrance drive roll 21 stops for connection of the strip W,
Since V ₁ - V ₂ ≒ 0 becomes V ₁ - _{V 2} < 0, the excitation current is reduced to a small value and a braking force is applied immediately for a predetermined period of time, and the belt-shaped object W is moved only by the gravity of the balance difference between the carriage 3 and the weight 9. By applying tension, the subsequent generation of large tension can be prevented. In addition, on the other hand, the entrance drive roll 2
1 starts and when V ₁ -V ₂ <0 becomes V ₁ -V ₂ >0, the excitation current is increased to increase the braking force, and the carriage 3 is lowered so as to increase the tension on the strip W. This can be dealt with by letting them know.

As is clear from the above explanation, according to the present invention, an upcoming steep tension fluctuation can be predicted from the sign change of the difference in conveying speed of the strip on the inlet and outlet sides, and the braking force of the powder brake can be adjusted in advance. Because of this control, the risk of damage to the surface of the strip even when the inlet (outlet) drive roller starts, stops, or decelerates can be reduced to about 10% compared to conventional rollers. .

In addition, if the powder brake 16 is made to be able to adjust the braking force with a dial, the dial can be adjusted in accordance with the band-shaped object, so that it can be easily applied to a wide range of band-shaped objects.

[Brief explanation of the drawing]

Figure 1 is a graph showing the relationship between starting and stopping of the entry drive roll and web tension fluctuations and the principle of the present invention, Figure 2 is a schematic perspective view of the accumulator according to the present invention, and Figure 3 is the figure 2. FIG. 4 is a sectional view taken along the - line in FIG. 2. W...Strip material, 1...Accumulator, 2,
4... Roll, 3... Carriage, 7... Chain, 10... AC geared motor, 12... Cam clutch, 13... Transmission shaft, 16... Powder brake, 21, 22... Drive roll, 23, 24
... Tacoze Serator, 25 ... Comparator, 26 ...
Corrector, 27... tension detector, 28... setting device,
29...PI regulator.

Claims (1)

[Scope of utility model registration request] In the unwinding section or winding section of the conveyor equipment for strip-like material,
An accumulator consisting of a plurality of fixed rolls and a movable roll attached to a carriage that can be raised and lowered is provided, and the belt-shaped article is alternately wound between the fixed rolls and the movable roll to apply a predetermined tension to the belt-shaped article. , a powder brake that suppresses the upward and downward movements of the carriage by changing the excitation current according to tension fluctuations of the strip; a constant speed motor that applies driving force to the powder brake; a speed detector that detects the speed at the side; and when the speed difference from the detector changes to either positive or negative within a predetermined range, an excitation current for the powder brake is applied for a predetermined time in a manner superimposed on the excitation current. A tension characteristic variable type accumulator comprising: a regulator;