JPH0155177B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a running sheet tension control device using dancer rollers.

The present inventor has developed a dancer roller 1 as shown in FIG.
We have already developed a tension control method using this method.

That is, the dancer roller 1 in FIG. 1 is given a pushing force F that is a combination of its own weight and the pulling force of the fluid pressure cylinder 3 (generally), and a tension of 1/2 F is applied to the running sheet S. is giving rise to Therefore, by appropriately adjusting the pulling force of the cylinder 3, the tension of the traveling sheet can be directly controlled.

However, unlike a dancer roller supported by a general coil spring, the dancer roller 1 supported by a piston rod of a fluid pressure cylinder 3 does not move easily, and even though the approximate tension of the traveling sheet S can be controlled, there are minute tension fluctuations. I could not hope for the ability to eliminate it. this is,
This is an unavoidable drawback because the movement of the dancer roller is controlled by a fluid pressure cylinder with a lot of friction.

In this invention, the control means for the extrusion force F shown in FIG. 1, which is a requirement for tension control by the dancer roller, is changed from a fluid pressure cylinder with a lot of friction to a frictionless spring itself.

However, if the fluid pressure cylinder 3 shown in FIG. 1 is not used and the roller is supported only by a spring like a normal dancer roller, it is impossible to maintain the pushing force F at the required value. Since the dancer roller moves up and down due to changes in sheet speed and tension, the pushing force F cannot be kept constant unless the spring itself moves up and down.

The present invention thus obtained will be described with reference to the embodiment shown in FIG. A dancer roller 1 indirectly supported by a spring 4, a sheet speed control unit 5 that detects the floating of the dancer roller 1 and adjusts the sheet feeding speed to return it to the home position A, and a spring that supports the dancer roller 1. A spring fixed end drive section 6 supports the fixed end 4a of the spring 4 and drives the fixed end 4a in a direction to increase or decrease the reaction force of the spring 4, and a setting section 7a sets a sheet tension pattern. Running sheet tension by a dancer roller equipped with a pushing force control section 7 that controls the driving force of the spring fixed end drive section 6 necessary to obtain a predetermined sheet tension value based on the take-up amount input from the take-up amount measuring device. It is a control device.

FIG. 2 shows an embodiment of a sheet winding device, in which a sheet S on a running path is tensioned between a sheet roll R of a winding machine 8 and a pinch roller 9 that rotates in synchronization with the winding. , the required tension is applied by an intermediate dancer roller 1. 8a is a winding motor, which rotates the sheet roll R.
If the rotation of the dancer roller 1 is accelerated, the dancer roller 1 will be pulled up, and if the rotation is decelerated, the dancer roller 1 will be lowered. However, the winding machine 8 may be rotated in synchronization with the pinch roller 9, and the rotational speed of the pinch roller 9 may be controlled.

The sheet speed control unit 5 utilizes this characteristic, and when the contact position between the dancer roller 1 side pointer 1a and the potentiometer 5a of the detector moves higher or lower than the fixed position A, the control unit 5 This is a control mechanism that sends signals to reduce and accelerate the speed of the motor 8a.

The driving section 6 of the spring fixed end 4a, the pushing force control section 7 that controls it, the setting section 7a attached thereto, etc. will be explained with reference to FIG. By providing the gradual decrease line, winding tension gradual decrease control is performed with higher precision than the torque control of the winder 8. However, the tension may be controlled so as to obtain a low tension or a gradually increasing tension.

FIG. 4 shows an embodiment in which the present invention is applied to a sheet feeding device, in which the first and second pinch rollers 10 and 11 may be synchronously interlocked, but in this case, the fine speed change device 12
By interlocking them via the , it is possible to apply basic tension to the sheet S on the traveling path. and,
The dancer roller 1 of the present invention is intervened at the intermediate position, thereby increasing the sheet tension to the required level. In this embodiment, the first pinch roller 10 on the upstream side is driven by the feed motor 13 via the fine speed change device 12, but the second pinch roller 11 on the downstream side may also be driven. Further, the pinch rollers 10 and 11 may be replaced with drive rollers (for example, S wrap rollers) that do not pinch the sheet.

In this case, the seat speed control section 5 uses an electric resistance type position detection device 5a and a fine speed change device 12.
The only difference from the seat speed control section 5 in Fig. 2 is that a mechanical operating section 5b is added to change the speed change rate of the motor (for example, a cone pulley or belt mechanism), and since this point is well-known technology, it will not be explained in detail. is omitted. The spring fixed end drive section 6 and the extrusion force control section 7 are the second
It is no different from the one in the picture. The dancer roller 1 is supported by the spring 4 by the swing lever 17 as shown in FIG.
You may also support them indirectly by cooperating with them. Note that a well-known floating guide mechanism for the dancer roller is used, so the illustration is omitted.

Next, an embodiment of the spring fixed end drive section 6 and the pushing force control section 7 will be explained with reference to FIG.

In this embodiment, the spring fixed end driving section 6 is a pneumatic cylinder, and the pushing force control section 7 includes an electro-pneumatic conversion valve 7d, an electronic circuit for calculation 7e, and a setting section 7a. The lower pressure regulating valve 7c applies pressure to the lower side of the piston to offset the weight of the dancer roller 1.

In the embodiment shown in FIG. 2, in order to perform tension control in an arbitrary pattern, a pattern calculation formula for determining the push force F is given to the calculation electronic circuit 7e, and its constant is set and given to the setting section, or , Calculate the winding amount (variable) from the winding amount measuring device to find the pushing force F (twice the required sheet tension), and also the value of the pressure that should be sent to the upper side of the piston for this purpose. The amount of electricity is obtained using a calculation formula given in advance, and this is sent to the electric-pneumatic conversion valve 7d. Therefore, the valve 7
Fluid at a required pressure is sent to the upper side of the piston from d to drive the fixed end 4a of the spring 4 and apply a required pushing force F to the dancer roller 1.

Although the sheet tension control pattern is not limited to a linear pattern and may be various, a specific implementation method will be described below using the simplest pattern shown in FIG. 3 as an example.

The object to be controlled is the sheet tension T, which is always 1/2 of the pushing force F of the dancer roller 1, so
In FIG. 3 showing the control pattern, the vertical axis represents the extrusion force F, and the horizontal axis represents the sheet winding amount x, which is a variable.

If the initial extrusion force is Fo and the gradually decreasing inclination angle is θ, then
The calculation formula for this pattern is F=Fo−tanθx. These Fo and θ are set using the digital setting device of the setting section 7a or the knob of the variable resistor.
The pushing force F determined for the momentary winding amount x and the fluid pressure P to be applied to the piston can be easily calculated from P=F/Q, where Q is the effective area of the piston. The electric-pneumatic conversion valve 7d receives this P as an electric signal, lowers the original pressure of the pressurized fluid to P, and sends it to the upper side of the piston of the cylinder 6.
Therefore, a downward pushing force F is applied to the dancer roller 1, whose gravity has been offset by the pressure below the piston. Since the dancer roller 1 is held in a fixed position by the action of the sheet speed control section 5, the dancer roller 1 is moved only by the pressure below the piston of the cylinder 6.
When the coil spring was suspended, the fixed end 4a of the coil spring was
When the upper side pressure of the piston is applied, the piston lowers by that amount, and the reaction force of the spring 4 becomes the weight of the dancer roller 1 minus the pushing force F (tension T x 2).
Since the position of the piston of the cylinder 6 is maintained above the home position at a height equal to the length of the coil spring 4 plus the length of the piston rod, the cylinder 6 is fixed at a suitable height.

The pneumatic cylinder 6 in this embodiment has a spring fixed end 4
In addition to the function of providing the necessary extrusion driving force to a, it also provides a cushioning effect. That is, the spring 4 freely floats and absorbs changes in the speed and tension of the traveling sheet, but as the amount of floating increases, the spring reaction force changes and the pushing force F of the dancer roller 1 also changes, so the sheet tension is reduced. It cannot be held constant. In such a case, when the floating amount is about to increase, the piston in the cylinder 6 moves to overcome the air pressure supplied from the electro-pneumatic conversion valve.
Unexpected fluctuations in the extrusion force F can be kept within a small range, and when even more rapid tension fluctuations occur,
Sudden changes in sheet tension are suppressed by the movement of the piston due to the compression or expansion of air due to the reaction force acting on the piston.

Although one embodiment has been described above, the present invention can be varied and applied in a variety of ways depending on the implementation conditions and the well-known techniques of machine designers without changing its gist. For example, springs are not limited to coil springs;
A leaf spring or the like can also be used with a dancer roller attached to one end and the other end used as a fixed end. In all of the embodiments, the dancer roller 1 hangs down perpendicularly from the horizontal traveling path of the sheet S, so the explanation has been made accordingly, but of course the dancer roller 1 is not limited to the hanging position. The floating of the dancer roller can be detected in addition to the above embodiment.
This may be done by providing various detectors above and below the fixed position. The spring fixed end drive section may be any other drive section incorporating a magnetic particle clutch or the like, as long as it has a damping effect similar to that of a pneumatic cylinder that produces internal slip due to an increase or decrease in spring reaction force.

According to this invention, since the dancer roller is supported by a spring, it floats lightly without frictional resistance, absorbs changes in the speed and tension of the sheet on the running path, and prevents fluctuations in the overall tension. When the floating range becomes large and the change in push force of the dancer roller due to the increase/decrease in spring reaction force and the resulting change in sheet tension become large, the sheet speed control section operates to return the dancer roller to a fixed position. Since it is returned to its original state, tension fluctuations can be kept within a small range.

This invention holds the dancer roller at a substantially fixed position using a sheet speed control section, and provides a pushing force control section that controls the fixed end of a spring that supports the dancer roller. Changes in the spring reaction force that occurred were now used as a means of controlling the tension of the traveling seat.
The fixed end of the spring is driven by the spring fixed end drive unit,
Since the dancer roller pushing force and the resulting sheet tension are controlled by changing the spring reaction force, it is extremely effective in controlling the tension pattern based on the instantaneous winding amount. In other words, since the speed of the drive mechanism of the take-up shaft and drive roller is controlled based on the detected tension value, it is not affected by inertia or friction loss, and
The response is quick. On the other hand, especially on the running path where the sheet is pulled out from an eccentric web, the running tension varies greatly with each rotation of the web, so conventional dancer rollers could not fully absorb the fluctuations. According to the sheet speed control unit, the floating of the dancer roller, the expansion and contraction of the spring, and the swinging can be kept small, and even minute and short-cycle tension fluctuations that the drive mechanism cannot respond to can be absorbed by the displacement of the spring. Since this is possible, stable control can be performed even in a very low sheet tension range.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of a conventional tension control method using a dancer roller, Fig. 2 is an explanatory diagram of one embodiment of the present invention, Fig. 3 is an explanatory diagram of a tension control pattern, and Fig. 4 is an explanation of another embodiment. FIG. 5 is an explanatory view of the spring fixed end drive section and the pushing force control section, and FIG. 6 is an explanatory view of the main part of another embodiment. DESCRIPTION OF SYMBOLS 1... Dancer roller, 5... Sheet speed control section, 6... Spring fixed end drive section, 7... Extrusion force control section.

Claims (1)

[Claims] 1. Directly between the front and rear guide rollers of the sheet running path so as to float according to fluctuations in the running tension of the sheet.
A dancer roller indirectly supported by a spring, a sheet speed control unit that detects the floating of the dancer roller and adjusts the sheet feed speed to return it to the normal position, and a fixed end of the spring that supports the dancer roller. a spring fixed end drive unit that supports the spring and drives the spring in a direction that increases or decreases the reaction force of the spring; a setting unit that sets a sheet tension pattern;
an extrusion force control unit that controls the driving force of the spring fixed end drive unit necessary to obtain a predetermined sheet tension value based on the set value and the take-up amount input from the take-up amount measuring device; A running sheet tension control device using a featured dancer roller.