JP5618739B2 - Belt machine - Google Patents

Description

  The present invention relates to a belt machine to which a metal endless belt is applied.

  Optical film production equipment requires high film quality, and the required level continues to rise. In these film manufacturing apparatuses, a belt machine having a metal endless belt whose surface is polished to a mirror surface is often used. For example, in a solution casting method in which a molten dope is cast on a metal endless belt to form a film, the mirror surface shape is transferred to a film, so that high mirror surface accuracy and smoothness are required. In such a high-precision metal endless belt, if the meandering and vibration that swings to the left and right during the running affect the film quality, smooth running stability is required.

  In general, in a belt machine that rotates an endless belt with a belt rotating roll, it is known to install a support roll for the purpose of suppressing vibration and meandering of the endless belt.

In particular, when the support roll is arranged so that the surface side of the endless belt is in contact with the lower end of the endless belt that runs horizontally, the mirror surface is damaged, so it is essential to arrange the support roll on the back side of the endless belt. .
Various studies have been made regarding the arrangement of support rolls, and the following prior art documents are available.

  Patent Document 1 (Japanese Patent Application Laid-Open No. 2003-21468) relates to the arrangement of guide rolls (support rolls) with respect to the arrangement at a higher position on the center side of the conventional art (that is, the entire arrangement is convex). A method is disclosed in which the uppermost portions of the guide rolls are arranged in a row so as to have the same height as a straight line connecting the uppermost portions of the driving drum and the driven drum.

  In the film manufacturing method described in Patent Document 1, guide rolls are arranged in a row on the back surface of the upper transition portion of a metal endless belt, and a cylinder is fixed to a driven drum movable in the belt tensioning direction. ing. When this cylinder is operated to increase the belt tension and reduce the bending of the endless belt, the contact angle between the endless belt and the support roll becomes small, and the possibility of occurrence of slip increases. That is, in this method, it is necessary to positively lower the belt tension, which makes it difficult to ensure running stability. Moreover, unless a support roll is installed not only on the upper part of the endless belt but also on the lower part, the vibration of the endless belt cannot be suppressed, which may affect the quality of the film.

  Patent Document 2 (Japanese Patent Application Laid-Open No. 2008-221546) discloses that a rubber band is sandwiched between the support roll and the back surface of the endless belt as a method for reducing the pressing force of the endless belt against the support roll during film production. A method is disclosed. According to this method, even when the pressing pressure is strong, the endless belt composition can be prevented from transforming from austenite to martensite, and as a result, thickness unevenness of the film can be eliminated.

However, this does not disclose the adjustment of the pressing pressure. When the contact angle is small and the pressing pressure is too weak, the support roll does not rotate with only the pressing pressure from the endless belt, slip occurs, and a lot of wear powder is generated. In particular, in the case of a free roll that does not have power, such as a tendency drive, wear powder is remarkably generated. These abrasion powders do not disappear unless a cleaning operation such as positive wiping is performed, and adhere to and accumulate on the back surface of the metal endless belt or the surface of the support roll. If the belt surface rises in a convex shape due to this accumulation, the contact area between the metal endless belt and the support roll is reduced, the contact pressure is locally increased, and this leads to an increase in wear powder at the portion. Eventually, at the portion where the wear powder accumulates, streaks appear on the mirror side of the metal endless belt. This streak-like unevenness is often transferred to a film, and has a significant effect on film quality.

  In Patent Document 3 (Japanese Patent Laid-Open No. 2002-307460), the distance between the support rolls is set to 5 m or less in order to suppress the vibration of the endless belt, or the distance between the support rolls on the upper side of the endless belt is set on the lower side. A method of reducing the variation in optical characteristics of the film by making it narrower than that to achieve a target retardation value is disclosed. In this method, in addition to the pressing force based on the tension of the metal endless belt, the endless belt's own weight is applied to the support roll on the upper side of the endless belt in the same direction, so as to press the roll. A force in the direction in which the weight of the metal endless belt tends to be separated from the roll, that is, the direction opposite to the pressing force by the tension, is applied to the support roll of the lower transition portion. In Patent Document 3, the distance between the support rolls is defined in order to suppress variations in the retardation value of the film. Therefore, if the support roll is not properly arranged and the contact angle is too large, the pressure applied by the belt tension becomes strong, and the roll and the metal endless belt generate a lot of wear powder due to metal contact, and meandering control is difficult. The problem of becoming.

JP 2003-21468 A JP 2008-221546 A JP 2002-307460 A

In order to suppress wear of the endless belt and the support roll as described above, to prevent streaky unevenness of the endless belt, and to run the endless belt stably without meandering, the support roll is properly arranged and an appropriate push It is necessary to obtain pressure, and for this purpose, the tension, contact angle, deflection, etc. of the metal endless belt must be determined. However, there is no document that discloses what the optimum value of the pressing force received by the support roll is, and a specific method for making the optimum value, and the current situation is that it is appropriately determined by the designer.
The present invention provides a belt machine that suppresses slip and wear between an endless belt and a support roll, prevents the occurrence of streaky unevenness of the endless belt, and allows the endless belt to run stably without meandering. It is intended to provide.

The basic configuration of the present invention includes at least two belt rotation rolls, a metal endless belt that is stretched over the belt rotation roll and can run horizontally, tension adjustment means for the endless belt, and the endless belt. A belt machine having a plurality of support rolls in contact with each other, wherein the support roll has an outer diameter of 100 to 200 mm, the support roll is disposed so as to contact the back side of the upper and lower transition portions of the endless belt , The endless belt tension adjusting means includes a slide mechanism that allows the rotating roll to move in the running direction of the endless belt, and a distance and height adjusting mechanism between the support rolls, and the tension T of the endless belt, In addition, considering the mounting distance between the support rolls and the bending caused by the belt tension, Contact angles θ1, θ2: θ1 ′, θ2 ′ between the endless belt and the upper and lower support rolls determined by adjusting the mounting height of the belt, and loads F1, F2 applied to the upper and lower support rolls generated from the endless belt; F1 The pressing pressure calculated from ', F2' is 0.1 to 10 N / cm. According to a preferred aspect, the bearing of the support roll is an oil bath bearing.

ADVANTAGE OF THE INVENTION According to this invention, abrasion with a metal endless belt and a support roll can be suppressed, the striped nonuniformity of an endless belt can be reduced, and the life of an endless belt can be extended.
The meandering and vibration of the metal endless belt can be suppressed, and the running stability of the endless belt can be ensured, and the quality of products for optical applications and the like is improved.
In addition, slipping between the support roll and the metal endless belt is prevented, leading to a reduction in load (lower energy) during operation of the apparatus.
Furthermore, by reducing the deflection of the support roll, the roll outer cylinder material is made thinner, the shaft diameter is reduced, the frame is simplified, the degree of freedom in design is improved, and the cost is reduced.

It is a schematic block diagram which shows an example of the belt machine for implementing this invention. It is the schematic which shows the bending of an endless belt. It is the schematic which shows the relationship between the contact angle of a support roll and an endless belt, and the pressing force by belt tension. It is attenuation | damping explanatory drawing of the support roll rotation speed when using a bearing with a shaft diameter of φ45 mm. It is attenuation | damping explanatory drawing of the support roll rotation speed when using a bearing with a shaft diameter of φ17 mm.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 schematically shows the overall configuration of the belt machine of the present invention.
The belt machine includes at least two belt-rotating rolls 2 and 3, a metal endless belt 1 that is stretched over the belt-rotating rolls 2 and 3 and can run horizontally, tension adjusting means for the endless belt 1, A plurality of upper support rolls 4 and lower support rolls 5 in contact with the back surfaces (inner sides) of the upper transition portion and the lower transition portion of the endless belt are provided.
Hereinafter, these structural members will be described.

(Metal endless belt)
The material of the endless belt 1 made of metal is not particularly limited as long as it is a metal, but is preferably stainless steel from the viewpoint of durability. In the present invention, the thickness is preferably 1 mm or more and the width is 1000 mm or more.

(Belt rotation roll)
The belt machine of the present invention has at least two rolls 2 and 3 for rotating the metal endless belt 1. When two belt rotating rolls 2 and 3 are used, one of them is usually a driving roll and the other is a driven roll. One or more endless belt rotation rolls may be provided between the two belt rotation rolls 2 and 3. The belt rotating rolls 2 and 3 rotate the driving roll 2 by a roll driving device (not shown) such as a motor, and the driven roll 3 rotates as the driving roll 2 rotates. A metal endless belt 1 is stretched between the drive roll 2 and the driven roll 3.

(Endless belt tension adjustment means)
The belt machine of the present invention has a slide mechanism 6 that allows any one of the belt rotating rolls 2 and 3 to move in the endless belt traveling direction, and a mechanism for adjusting the distance and height between the support rolls described later. The tension of the metal endless belt 1 can be adjusted by adjusting the distance and height between the slide mechanism 6 and the support roll. As shown in FIG. 1, the slide mechanism 6 according to the present embodiment is a mechanism for moving the roller bearing 3 a on the driven roll 3 side in parallel with the endless belt traveling direction, and supports the load applied to the bearing 3 a, for example. By providing the slide rail 8 on the body 7, it can be slid along the slide rail 8. At that time, the power can be operated using an air cylinder or a hydraulic cylinder. In that case, the cylinder body 9a may be attached to a support 7 such as a frame structure (not shown) constituting the belt machine. A tip end portion of a piston rod 9b attached to the cylinder 9 is fixed to a part of the bearing 3a.

(Support roll)
The plurality of upper and lower support rolls 4 and 5 are disposed so as to contact the back side (inside) of the upper and lower transition portions of the endless belt 1. In order to adjust the belt tension of the metal endless belt 1 together with the slide mechanism 6, the upper and lower support rolls 4 and 5 are provided with an adjustment mechanism (not shown) that can adjust the distance between the rolls and the installation height. A known mechanism can be adopted as the adjusting mechanism itself.

The outer diameter of the upper and lower support rolls 4 and 5 is preferably φ100 mm to φ200 mm with a relatively small moment of inertia. If the outer diameter is too large, the moment of inertia will increase, and the rotational speed of the upper and lower support rolls 4 and 5 will not easily follow the fluctuation of the running speed of the endless belt, and the upper and lower support rolls 4 and 5 will easily slip.
For the bearings used for the upper and lower support rolls 4 and 5, although not shown in the drawing, it is preferable to use an oil bath type with a small rotational resistance, and if necessary, auxiliary power such as a tendency drive can be provided to reduce slip. .

In order to suppress wear due to contact of the metal endless belt 1, it is preferable that the surface of the support roll is subjected to a treatment such as hard chrome plating and the surface hardness thereof is set to Hv 800 or more.
Further, the surface of the support roll may be subjected to rubber lining or resin lining, and it is preferable to increase the frictional force with the metal endless belt 1 to suppress slip and to avoid the generation of wear powder by avoiding contact between metals. .

As described above, by adjusting the tension of the metal endless belt 1 and the arrangement (distance and height between the support rolls) of the upper and lower support rolls 4, 5, the endless belt that is applied to the upper and lower support rolls 4, 5 is adjusted. The pressing pressure from can be generated. It is preferable to adjust the pressing pressure to be 0.1 to 10 N / cm . The “height” of the support roll means the position in the vertical (vertical) direction.

  The distance between adjacent rolls of the upper support roll 4 and the lower support roll 5 is preferably 2 m or more and 8 m or less. If the distance between the upper and lower support rolls 4 and 5 is too short, the number of rolls increases, which not only leads to an increase in cost but also tends to increase the number of contact with the endless belt 1 and increase the amount of wear. If the distance between the upper and lower support rolls 4 and 5 is too long, it is difficult to suppress vibration of the metal endless belt 1, and a film (not shown) on the metal endless belt 1 tends to be affected by vibration. Adjustment of the distance and height between the support rolls is performed by a slide mechanism (not shown) in the direction of the arrow attached to the upper and lower support rolls 4 and 5 as shown in FIG. The slide mechanism may be a mechanism that is fixed to the elongated hole with bolts, and does not require a particularly complicated mechanism, and may be any mechanism that can move the position of the support roll bearing.

The pressing pressure is determined by adjusting the tension of the endless belt and the arrangement of the upper and lower support rolls 4 and 5, that is, the distance and the height.
What is necessary is just to arrange | position the upper support roll 4 distribute | arranged to the upper transition part of the metal endless belt 1 in the location which can support the bending by the dead weight of the metal endless belt 1. FIG. For the lower support roll 5 arranged in the lower transition portion of the metal endless belt 1, the endless belt deflection amount is obtained by the method described below, and a suspension curve is drawn from the result, and the lower support roll is along the curve. 5 is determined (see FIG. 1).

The bending of the metal endless belt 1 can be obtained by the following known formula.
That is, the amount of deflection (D) of the endless belt 1 generated at the center between the centers of the two belt rotating rolls 2 and 3 due to the tension of the metal endless belt 1 is:
D = A ² × B × S × γ / 7.93H
A: Distance between rotating rolls (mm)
B: Width of metal endless belt (mm)
S: Metal endless belt thickness (mm)
γ: specific gravity of metal (7.9 × 10 ⁻⁶ kg / mm ³ )
H: Tension (kgf)
Is calculated by
The lower support roll 5 is arranged along a bending curve (suspension curve) of the metal endless belt 1 in consideration of the bending.

3A and 3B are diagrams showing the relationship between the contact angles θ1, θ2, θ1 ′, and θ2 ′ between the upper and lower support rolls 4 and 5 and the metal endless belt 1 and the pressing force due to the belt tension.
The belt tension in the belt machine is preferably 30 to 70 N / mm ² .
When the load generated from the endless belt tension T is F1, F2, F1 ′ and F2 ′, and the weight of the endless belt is F3 and F3 ′, F1 and F2 are F1 = T × SINθ1, F2 = T × SINθ2, F1 respectively. 'And F2' are represented by F1 '= T × SINθ1' and F2 '= T × SINθ2', respectively. The pressing force from the endless belt 1 received by the upper and lower support rolls 4 and 5 is represented by F1 + F2 + F3 for the upper support roll 4 and F1 ′ + F2′−F3 ′ for the lower support roll 5.

  The contact angle between the metal endless belt 1 and the upper and lower support rolls 4 and 5 is calculated from the mounting height of the upper and lower support rolls 4 and 5 in consideration of the mounting distance of the upper and lower support rolls 4 and 5 and the bending caused by the belt tension. Is done.

The pressing pressure is in the range of 0.1 to 10 N / cm , and more preferably in the range of 2.5 to 7.5 N / cm .
If it is less than 2.5 N / cm , the risk of endless belt and slip increases, and the risk of damage to the back of the endless belt and the support roll increases.
If it exceeds 7.5 N / cm , the contact resistance to the support roll increases and the endless belt becomes difficult to move in the width direction, making it difficult to control the endless belt meandering, and the amount of wear increases, resulting in a large amount of wear powder. Occur.

If the generated wear powder is not cleaned regularly, it accumulates on the back of the endless belt or on the surface of the support roll, and the portion where the metal powder accumulates is convex, which increases the contact surface pressure and increases the amount of wear. Leads to an increase in
As the pressing force increases, the force applied to the upper and lower support rolls 4 and 5 also increases, so that the shaft diameter increases and the wall thickness increases in order to ensure the support roll strength, leading to an increase in cost.

  Actually, the support rolls were set on two types of bearings, the rotational resistance was measured, and the pressing pressure capable of rotating the support roll without slip was verified.

Specifically, using a support roll 4 with a hard chrome plated surface with a diameter of 150mm and a width of 1800mm, the support roll is rotated using a pillow block bearing with a shaft diameter of 45mm and an oil bath bearing with a shaft diameter of 17mm. A test was conducted to determine how much torque is required for the rotation, and at the same time how much force is transmitted from the endless belt to rotate the support roll. The test specifications are as follows.
(1) Load W ₁ applied to the support roll
0.1 N / cm (pressing pressure) × 180 cm (roll width) = 18 N (1.8 kgf)
(2) Support roll weight W ₂
120kg
In this test, as shown in FIGS. 4 and 5, the rotational speed decay state (change in rotational speed over time) is set by placing a roll with a bearing set on a flat floor surface, rotating it strongly by hand, and using a stopwatch. This is based on the rotational resistance obtained by the following equation when the rotational speed is read at regular intervals and this is continued until the roll stops.
T = GD ² × N / 375t
T (rotational resistance: kgf · m), GD ² (moment of inertia: kgf · m ² ), N (initial rotational speed: rpm), t (required time to stop: sec)
μ = T / (W ₂ × d)
μ (friction resistance), W ₂ (weight of support roll: kg), d (bearing inner diameter: mm)
The test for the pillow block bearing was conducted after removing and cleaning the grease inside the bearing. The number of roll rotations was measured with a reflective digital tachometer DT-205 (manufactured by Nidec Simpo).

As a result of the above test, in the pillow block bearing having a shaft diameter of 45 mm, the rotation speed N at the start of rotation of the support roll was 338 rpm as shown in FIG. 4, and the time t until the stop was 80 sec. The rotational resistance T at this time was 0.0186 kgf · m, and the frictional resistance μφ ₄₅ 6.89 × 10 ⁻³ of the bearing was obtained. On the other hand, in the oil bath bearing with a shaft diameter of φ17 mm, the rotation speed N at the start of rotation of the support roll was 362 rpm as shown in FIG. 5 and the time t until the stop was 470 sec. The rotation resistance T0 of the oil bath bearing was 0.0034 kgf · m, and the friction resistance μφ ₁₇ 3.33 × 10 ⁻³ of the bearing was obtained. When these μ values are used to convert the rotational resistances T′φ ₄₅ and T′φ ₁₇ of the bearings having the shaft diameters of φ45 mm and φ17 mm in the support roll φ150 mm, respectively,
T′φ ₄₅ = 2 × W ′ · d · μ / 2 = 0.0189 kgf · m
T′φ ₁₇ = 2 × W ′ · d · μ / 2 = 0.0034 kgf · m
It becomes. However, W ′ = (W ₁ + W ₂ ) / 2.

Next, the rotational torque from the belt acting on the support roll will be considered. Here, it is assumed that the roll weight is not added to calculate how much force is transmitted from the belt to rotate the support roll.
(1) Rotational force F = μW ₁
μ: Mild steel and mild steel 0.15 to 0.2 to 0.1.
W1: 18N (1.8kgf)
(2) the rotational torque T _o = Fr
0.020 kgf · m> 0.0189 kgf · m (T′φ ₄₅ )> 0.0034 kgf · m (T′φ ₁₇ )
According to the result of (2), when viewed from the viewpoint of slip occurrence, the rotational resistance of the pillow bearing (φ45 mm) is about five times larger than that of the oil bath bearing (φ17 mm), and further against the rotational resistance of the bearing. The rotational torque from the belt is a value with no margin, and the risk of slippage due to deterioration of the bearing is very high.

As can be understood from these test results, the resistance can be reduced by reducing the inner diameter of the bearing, and the μ value can be reliably reduced by changing the bearing to the oil bath type, but operation without slipping is ensured. In order to achieve this, it can be said that a pressure of 0.1 N / cm is weak.

That is, in the present invention, from the above test results, it is effective to use an oil bath type ball bearing for the support roll bearing in order to reduce the rotational torque. In order to reduce the GD ² (moment of inertia) of the roll, it is also effective to reduce the shaft inner diameter and reduce the weight of the roll body.

Moreover, in the case of a pillow block bearing that is generally used, it has been found that the rotational resistance is large, and the risk of slipping is high at a pressing force of 0.2 N / cm or less.
On the other hand, in the case of an oil bath bearing with low rotational resistance, the result does not slip in the calculation, but in reality it varies depending on various conditions (roll moment of inertia, speed, bearing, etc.) and is grasped by simple measurement. It is considered that a difficult minute slip of 1% or less is actually generated.

As described above, the determination of an appropriate support roll arrangement is very important for the purpose of extending the endless belt life. Even if wear powder is removed by regular cleaning if the pressing force is strong, contact with the endless belt is strong, and it is difficult to stabilize meandering control because the endless belt does not move in the width direction on the support roll. Become. By making the pressing pressure appropriate, the endless belt driving force can be reduced and the energy can be reduced.
In the above embodiment, a single belt machine is taken as an example, but the belt machine of the present invention can be applied to a double belt machine as a matter of course.

  According to the present invention, wear of the metal endless belt and the support roll can be suppressed, streak-like unevenness generated in the endless belt can be suppressed, the life of the endless belt can be extended, and meandering and vibration of the metal endless belt can be suppressed. As a belt machine that suppresses the endless belt and has good running stability, it can be widely applied to various fields.

1 Metal endless belt 2 Roll for belt rotation (drive roll)
3 Roll for belt rotation (driven roll)
3a Bearing 4 Upper support roll 5 Lower support roll 6 Slide mechanism 7 Support body 8 Slide rail 9 Cylinder 9a Cylinder body 9b Piston rod

Claims (2)

A belt machine having at least two belt rotation rolls, a metal endless belt that is stretched over the belt rotation roll and can run horizontally, tension adjusting means for the endless belt, and a plurality of support rolls in contact with the endless belt Because
The outer diameter of the support roll is 100 to 200 mm, and the support roll is disposed so as to contact the upper side of the endless belt and the back side of the lower transition part,
The tension adjusting means of the endless belt includes a slide mechanism that allows the rotating roll to move in the traveling direction of the endless belt, and a mechanism for adjusting the distance and height between the support rolls,
The contact angle θ1 between the endless belt and the upper and lower support rolls determined by adjusting the mounting height of the upper and lower support rolls in consideration of the tension T of the endless belt, the attachment distance between the support rolls and the bending caused by the belt tension. , Θ2: The pressing pressure calculated from θ1 ′, θ2 ′ and the loads F1, F2; F1 ′, F2 ′ applied to the upper and lower support rolls generated from the endless belt is 0.1 to 10 N / cm. Belt machine. The belt machine according to claim 1, wherein the bearing for the support roll is an oil bath bearing.

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