JPS58148146A - Constant tension feeder - Google Patents

Abstract

PURPOSE:To enable the feeding of a sheet-shaped material at a fixed tension by imparting a braking force with an elastic member connected to a braking member provided rotatably on a sheet material feeder so as to adjust an elastic biased force following the rotation of a detection member. CONSTITUTION:In a feeder of a sheet material or the like designed to unwind a sheet-shaped material 7 at a fixed tension on a rotating shaft, a detection member 11 for detecting the wind diameter of the material 7 is provided rotatably in contact with the surface of the material 7 in the direction of the winding diameter while a braking member 17 is provided rotatably on a fixed section 15 of the feeder. An elastic member 14 is connected to the braking member 17 to adjust an elastically biased force following the turning of the detection member 11 and imparts a braking force to brake the rotating shaft. In other words, the increase in the tension with decrease in the winding diameter of the material 7 is balanced with decrease in the brake pressing force to keep the feeding tension of the material 7 constant thereby making the structure simple and thin.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for unwinding sheet-like materials such as thin plates and tapes, and more particularly to an apparatus for feeding these sheet-like materials wound in multiple turns at a constant tension.

Conventionally, various proposals have been made regarding a constant tension supply device that unwinds a spirally wound sheet material under constant tension. These constant tension supply devices are roughly divided into those in which a woodcutter's brake is directly attached to the supply side, and those in which the tension of the supplied material is directly detected by a low 2 or the like and the brake, etc. on the supply side is adjusted.

However, although the former can have a simple structure in a shed, it is necessary to adjust the braking force from time to time because the tension fluctuates due to changes in the diameter of the spiral feed material. The latter device is effective in stabilizing the tension because it detects the supplied material RAM, but even if the tension detection and brake control are performed mechanically or electrically, the FC location becomes complicated, large, and expensive. In particular, in order to detect tension, rollers, etc. are required on both sides (front and back sides) of the supplied material, and with regard to insulating tapes, etc. used for insulating conductors in electrical machines, mica etc. come into contact with the roller surfaces, resulting in a decline in product purchases. Such problems were occurring.

For this reason, there has been a demand for a constant tension supply device that can always supply a supply material at a constant tension regardless of changes in the winding diameter of the supply material, is compact, inexpensive, and does not have the above-mentioned drawbacks.

An object of the present invention is to provide a constant tension supply device which is made smaller and simpler in structure and has a thin structure.

The present invention is a sheet material supply device that unwinds a sheet material with a constant tension around a rotating shaft, and detects the winding diameter of the material on the surface of the spirally wound sheet material. A detection member is rotatably abutted in the winding radial direction, and a braking member is rotatably provided on a fixed portion of the supply device, and an elastic biasing force is applied to the brake member as the detection member rotates. It is characterized in that elastic members to be adjusted are connected, and the elastic members apply a braking force to brake the rotation of the rotating shaft.

The basic principle of the present invention will be explained below with reference to FIG.

In FIG. 1, the required tension k T of the sheet-like material (hereinafter referred to as supply material) 7 that is unwound from a spiral roll body and supplied.
The initial outer radius kl of the feed material, , the final outer radius @t Rt
, the brake force If, and the distance tr from the brake center to the point of application, the balance of forces at the initial outer radius is as follows: % Formula % (1) Here, the brake force f4q The pressing force of the brake shoe 20 P
and the friction coefficient μ are expressed as the following formula: % formula % (2) Since n, the above formula (1) becomes the following formula.

TwμP1r/R, (3) Therefore, the tension at the final outer radius is also expressed by the following formula: % formula % (4). From equations (3) and (4) above, the tension T changes as the outer radius changes (R,→R1), so in order to keep this tension constant, the pressing force Pt of the brake shoe is
It is clear that it will need to be changed as the outer radius changes.

Now, a detection arm 1lft is installed to detect the radius of the supplied material,
When this rotation angle is θ, the displacement art at a point of length b from the rotation axis center A is approximated by the following formula: % formula % (5) Also, the brake lever 17 provided with the brake 7 u 20
Assuming that the force kF received from the elastic body (tension spring, etc.) 14 at a point distanced by a distance d from the center of rotation B is given by the pressing force P of the brake shoe 20 that generates the braking force, F= (C+d)P/d ・・・・・・・(
6) is given by n.

Therefore, the pressing force Pt of the brake shoe - the spring coefficient of the spring 14 to be generated is calculated by the following equation.

K=F/a = (C1d)Δp/d/b# = (c+j) T (R1-1(t)idbθp
r・・・・・・(7) [In nine figures, from equations (3) and (4), ΔP=P+ Pt'='T (Rt Rt)/μr
] As described above, the change in the outer radius of the supplied material is detected by the arm, and the pressing force P of the brake shoe is changed by the spring having the spring coefficient K determined by equation (6). The tension of the material to be supplied can be kept constant at T'.

An embodiment of the present invention will be described below with reference to the drawings. Second
Figures 3 and 3 show a side view and a front view of a tape supply device that supplies unwound tape material under constant tension.

This device consists of a drum 4 rotatably attached to a shaft 2 attached to a base 1 by a pairing 3, a feed material 7 wound around a feed material core 8 attached to the drum 4, and a feed material 7 wound around a feed material core 8 attached to the drum 4. side plate 5 and mounting bolt 6 for holding 7 to drum 4;
Bin 1 in which the detection arm 11 is rotatably attached to the base 1
0 and the stay 9, a roller 12 rotatably attached to the tip of the detection arm and in contact with the outer surface of the supply material 7, a support part 13 fixed to the detection arm 11 after sliding positioning, and the support part n a tension spring 14, a bracket 16 and a stay 15 for rotatably attaching the brake arm 17 to the base 1;
A brake shoe receiver 19 rotatably supported by a pin 18 at the tip of the brake arm, a brake seat 1-20 attached to the brake lever 19, a support portion 21, and the tension spring 14.
The support s23 holds one end of the support part 23, and the support part 21
It is composed of a V@thick screw 22 whose position is adjusted by.

The operation of unwinding the supply material 7 and supplying it with a certain tension using this belt-like material supply device will be described. First, set the ai4JI screw 22 to give the required tension to the supply material 70.
The preload force of the tension spring 14 is adjusted to apply the required braking force to the brake drum 4. In this state, detection arm 1
1 is constantly pulled by the reaction force of the spring 14, and the detection arm 11
The end rollers 12 are constantly in contact with the outer surface of the feed material 7. Next, when the supply material 7 is completely unwound and feeding is started, the winding diameter (outer radius) of the supply material gradually decreases, and the detection roller 12 rotates inward with the winding diameter. This rotation causes the detection arm 14 and the support part 13 to rotate, and the displacement corresponding to the rotation angle n1 weakens the elastic biasing force of the tension spring 14, and the brake lever 17tJi is moved to the drum 4 of the brake shoe 20. Since the pressing force against the supply material 7 decreases, the increase in tension due to the decrease in the winding diameter of the supply material 7 and the decrease in the brake pressing force are balanced, and the supply tension of the supply material 7 is kept constant.

In addition, as a modification of the present invention, it is possible to further simplify by making the rotation center of the detection arm and the brake arm the same (AXB in Fig. 1), and when the tension is large, the pressing force of the roller at the end of the detection arm is Therefore, there is a method to increase the braking force by making the brake shoes and drum into a wedge shape.
Additionally, it is easily possible to add a simple booster mechanism to the brake arm to increase the braking force and reduce the roller pressing force.

According to the present invention, the tension can be kept constant regardless of changes in the diameter of the feed material with a simple structure. In addition, the detection port -
Since the roller contacts only one side of the material to be supplied, in the case of insulating tape for electrical machine conductors, etc., the quality of the insulation work can be improved by providing the detection roller on the long hitting material side.

In particular, in the present invention, it is difficult to accurately manufacture the springs, etc. that adjust the braking force to match the elastic coefficients, and since it is on the part side, the *Ifl lever and the sliding part on the brake lever are attached to the support part of the spring etc. A structure capable of dynamic positioning can be easily provided, and (c+d) /d b=z/ of the above formula (7) can be easily provided.
The ratio t of d b can be changed and concealed, and the amount of error in the spring coefficient of the manufactured spring can be easily corrected.

By widening the sliding positioning range of the support part, the required tension can be set within a certain desired range without having to specify a specific tension using the same spring, and a constant tension can be supplied, which is even more effective.

Further, according to the present invention, the device can be made several tens of percent thinner in the width direction of the feed material, and can be applied to rotating parts such as daping devices, resulting in significant effects such as quality improvement.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the principle of the present invention, and FIGS. 2 and 3 are a side view and a front view, respectively, of an embodiment of the present invention. -1st eye/l

Claims (1)

[Claims] 1. A detection member for detecting the winding diameter of the material with respect to the next surface of the 7-t-shaped material in the feeding device 9 for sheet material, etc., which unwinds the sheet material at a constant tension with the center of the rotating warehouse. are rotatably abutted in the winding radial direction, and a braking member is rotatably provided on the fixed part of the supply device, and the elastic biasing force is adjusted as the detecting member rotates. A constant tension supply device in which a braking force is applied by the elastic member to brake the rotating shaft.