JPH07303856A - Docter knife in coater for web - Google Patents

Abstract

PURPOSE:To provide a docter knife in which the degree of bending can be adjusted precisely even during the operation of a coater. CONSTITUTION:In a docter knife 10 which applies coating liquid on a web is formed in a cylindrical shape. A worm 30 is arranged in the radial direction inside the middle of the docter knife 10, a motor 36 having a worm gear 32, which moves the worm 30 in the radial direction, is installed inside the docter knife 10, the end of the worm 30 is pressed to the inner wall of the cylindrical docter knife 10 by moving the worm 30 in the radial direction by the motor 36, and the degree of the bending of the docter knife 10 is adjusted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a doctor knife in an apparatus for coating webs such as films, cloths and papers.

[0002]

2. Description of the Related Art Conventionally, there is a dam type coating apparatus 100 as shown in FIG. The coating apparatus 100 is provided with a comma type doctor knife 108 above a backing roll 102, and the dam plate 10 is provided in front of the doctor knife 108.
4 is provided to form the liquid reservoir 106.

When the coating liquid is applied to the web W, the coating liquid is stored in the liquid storage portion 106 formed by the dam plate 104, and the web W is run by the backing roll 102 to make the backing roll. The coating liquid is applied to the web W by the gap between the 102 and the doctor knife 108.

[0004]

However, in the coating apparatus 100 having the above-mentioned configuration, the coating pressure of FIG.
As shown in FIG. 3, there is a case where the central portion of the cylindrical doctor knife 108 bends upward, that is, bending occurs.

Therefore, as a doctor knife for adjusting the bending, a pressure type doctor knife for inflating the doctor knife in the radial direction by injecting a fluid such as air or oil into the doctor knife or a adjusting screw in the radial direction has been provided. A screw type doctor knife has been proposed which adjusts bending by moving an adjusting screw in a radial direction (Japanese Patent Publication No. 60-45949).

However, in the pressure type doctor knife, since the doctor knife is inflated by the fluid, the fluid has a cushioning property in the radial direction of the doctor knife. Therefore, the bending amount cannot be adjusted to be constant, and it is difficult to make the coating pressure uniform. Further, air or oil may leak from a pressure container, a tube, or the like for injecting the fluid inside the doctor knife, and the bending amount may not be controlled correctly.

Further, in the screw type doctor knife, it is necessary to temporarily stop the coating device and adjust the screw, which is troublesome for the work. Further, in order to measure whether or not the bending amount has changed, it is necessary to once stop the coating device and measure the same.

In view of the above problems, the present invention provides a doctor knife capable of finely adjusting the bending amount while the coating apparatus is operating.

[0009]

According to a first aspect of the present invention, there is provided a doctor knife for use in a web coating apparatus, wherein the doctor knife has a cylindrical shape, and the center of the doctor knife is a doctor knife for coating a coating liquid on a web. A worm is arranged inside, a motor is provided inside the doctor knife, and a worm gear for moving the worm in the radial direction is provided on a rotary shaft of the motor, and the worm is moved in the radial direction by the motor to move the worm. Press the tip of the worm against the inner peripheral wall of the cylindrical doctor knife to inflate it,
The bending amount of the doctor knife is adjusted.

[0010]

[Operation] The doctor knife in the web coating apparatus having the above-mentioned structure will be described.

When the doctor knife bends, a motor provided inside the doctor knife moves the worm in the radial direction, that is, in the direction in which the doctor knife is recessed, and pushes the tip of the worm against the inner peripheral wall of the doctor knife. Touch it and push the recessed part to inflate it to adjust the bending amount of the doctor knife.

In this case, since the motor is provided inside the doctor knife, the bending amount can be adjusted while operating the coating device.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

Reference numeral 10 is a comma type doctor knife used in the coating apparatus. This cylindrical doctor knife 10
Is formed of an outer cylinder 12 and an inner cylinder 14, and the inner cylinder 14 is concentrically arranged inside the outer cylinder 12 with a gap 16 therebetween.

Reference numerals 18 and 20 are shaft portions provided at both ends of the inner cylinder 14. The shaft portion 18 is provided with a through hole 22 for passing an electric cord described later.

Reference numerals 24 and 26 are ring-shaped edge portions provided on the peripheral portions of both ends of the outer cylinder 12.

Reference numerals 27 and 28 are ring-shaped connecting rings for connecting the shaft portions 18 and 20 and the edge portions 24 and 26 in a concentric manner. Specifically, as shown in FIG. 3, the inner side of the coupling ring 28 is pressed by the shaft portion 20 by the ring-shaped first pressing member 28a, and is fixed by the bolts 28b arranged in the axial direction. Furthermore, the connecting ring 2
The outer side of 8 is pressed by the edge portion 26 by the ring-shaped second pressing member 28c, and is fixed by the bolt 28d. Then, the outer cylinder 12 and the inner cylinder 14 form the connecting ring 2
Since they are connected by 8, the outer cylinder 12 can bend with respect to the inner cylinder 14.

Reference numeral 30 indicates the central portion of the inner cylinder 14,
It is a worm arranged in the diameter direction. This warm 30
Ha. The bearing is provided on the inner peripheral wall of the inner cylinder 14 so as to be diametrically movable and rotatable. Further, both ends of the worm 30 penetrate through the holes 38 and 40 provided in the inner cylinder 14 and project to the outside of the inner cylinder 14.

Reference numeral 32 is a worm gear for moving the worm 30 in the radial direction. The worm gear 32 is provided on the rotary shaft of the speed reducer 34.

Reference numeral 36 is a motor 36 for rotating the speed reducer 34, which moves the worm 30. The electric cord from the motor 36 is
It is arranged outside through the through hole 22 of the shaft portion 18.

Reference numerals 42 and 42 are pressing members arranged in the gap 16 between the outer cylinder 12 and the inner cylinder 14. The central portion 44 of the U-shaped pressing member 42 is recessed, and both end portions 46 thereof are
Protrudes and presses the inner peripheral wall of the outer cylinder 12 only with the both end portions 46, 46, and the central portion 44 thereof has the worm 30
Is pressed radially outward by the tip of the. Pressing member 4
A pair of 2 is provided on the axis. Therefore, when the worm 30 moves downward in FIG. 1, the lower pressing member 42 pushes up the central portion of the outer cylinder 12 downward, and when the worm 30 moves upward, the upper pressing member 42. Presses the inner peripheral wall of the outer cylinder 12 upward.

Reference numeral 48 is a gap sensor for measuring the size of the gap 16. The gap sensor 48 measures the size of the gap 16.

Reference numeral 50 is a dummy sensor provided at a position facing the gap sensor 48 with the pressing member 42 interposed therebetween. A metal is built in the inside of the dummy sensor 50, and when the metal expands due to the temperature, the measurement error due to the temperature of the gap sensor 48 is corrected with reference to the expansion ratio.

Reference numeral 52 is a control device for rotating the motor 36 in accordance with the signal from the gap sensor 48, and
A measurement error due to the temperature of the gap sensor 48 is corrected by the signal of the dummy sensor 50 (see FIG. 4). Further, the traveling speed of the web W is detected by the motor 56 that rotates the backing roll 102.

A case where the doctor knife 10 having the above structure is used in the dam type coating apparatus 100 shown in FIG. 6 will be described.

When the web W is conveyed by the backing roll 102, the coating liquid is supplied from the liquid reservoir 106 formed by the dam plate 104, and the doctor knife 10 and the backing roll 102 cover the upper surface of the web W. The coating liquid is applied. In this case, it is assumed that the coating pressure causes bending of the outer cylinder 12 of the doctor knife 10, and the central portion of the outer cylinder 12 is recessed and approaches the inner cylinder 14, resulting in the state shown in FIG. 7.

The gap sensor 48 measures the bending amount. That is, when the dimension measured by the gap sensor 48 becomes smaller than the set value, the inner cylinder 14
It is determined that the gap 16 between the outer cylinder 12 and the outer cylinder 12 is narrowed and bending is occurring, and this signal is output to the control device 52.

The control device 52 rotates the motor 36 by the signal from the clearance sensor 48 to move the worm 30 downward in FIG. 1, and adjusts the bending amount thereof. In this case, the pressing member 42 presses the inner peripheral wall of the outer cylinder 12 downward, but the pressing member 42 has a recessed central portion 44 and presses the inner peripheral wall of the outer cylinder 12 only by the both end portions 46, thereby making a single point. Since the state is not pressed but two points are pressed, the bending amount can be adjusted uniformly.

In the outer cylinder 12 pressed downward by the pressing member 42, the connecting ring 28 is curved so that the entire outer cylinder 12 bends downward. This makes it possible to adjust the bending amount.

When the doctor knife 10 is rotated 180 ° and used, the worm 30 shown in FIG. 1 is used.
If is moved in the opposite direction, the bending amount of the doctor knife 10 when rotated can also be adjusted.

Whether or not the bending amount can be adjusted is judged by a signal from the gap sensor 48, and feedback control is performed.

In the doctor knife 10 described above, the motor 36 is provided inside the inner cylinder 14, and the clearance sensor 4 is provided.
8 constantly measures the gap 16 between the outer cylinder 12 and the inner cylinder 14 to monitor the bending amount.
It is possible to adjust the bending amount in real time while driving 0. Further, since the bending amount changes depending on the traveling speed of the web W, the bending amount may be adjusted according to the traveling speed of the web W.

Further, since the worm 30 presses the inner peripheral wall of the outer cylinder 12 via the pressing member 42, it does not have the cushioning property unlike the pressure type doctor knife. Therefore, the coating pressure can be made uniform.

In the above embodiment, the dam type coating apparatus 1 is used.
No. 00 has been described, the doctor knife of the present invention is not limited to this, and a coating device having another structure may be used. Further, the doctor knife is not limited to the comma type and may be a roll type.

Further, in the above embodiment, the outer cylinder 12 and the inner cylinder 1
4, the outer cylinder 12 and the inner cylinder 14 are connected by a connecting ring 28. However, as shown in FIG. 5, a span ring 54 is provided between the outer cylinder 12 and the inner cylinder 14. Therefore, both movements may be allowed.

[0036]

As described above, according to the doctor knife in the web coating apparatus of the present invention, the bending amount of the doctor knife can be adjusted by moving the worm in the radial direction by the motor, so that the operation of the coating apparatus is stopped. Without changing the bending amount.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a doctor knife showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is an enlarged vertical cross-sectional view of a main part of a doctor knife.

FIG. 4 is a block diagram of the present embodiment.

FIG. 5 is an enlarged vertical cross-sectional view of a doctor knife of another embodiment.

FIG. 6 is an explanatory diagram of a dam type coating device.

FIG. 7 is a front view of the coating apparatus in a state where the doctor knife bends.

[Explanation of symbols]

 10 Doctor Knife 12 Outer Cylinder 14 Inner Cylinder 16 Gap 18,20 Shaft 28 Connecting Ring 30 Worm 32 Worm Gear 34 Reducer 36 Motor 42 Pressing Member

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuto Ueda 1-101 Kawai-cho, Kawai-cho, Kitakatsuragi-gun, Nara 1 Hirano Techseed Co., Ltd. (72) Masanobu Matsumoto 1-101 Kawai-cho, Kawai-cho, Nara, Japan 1 Hirano Techseed Co., Ltd. (72) Inventor Haruki Tsuchida 1 of 101 Kawai, Kawai-machi, Kitakatsuragi-gun, Nara Prefecture 1 Hirano Techseed Co., Ltd.

Claims (1)

[Claims] 1. A doctor knife for applying a coating liquid onto a web, wherein the doctor knife is formed in a tubular shape, a worm is arranged in a radial direction inside a center of the doctor knife, and a motor is provided inside the doctor knife. A worm gear for moving the worm in the radial direction is provided on the rotary shaft of the motor, and the worm is moved in the radial direction by the motor to press the tip of the worm against the inner peripheral wall of the cylindrical doctor knife to inflate the worm, A doctor knife for a web coating apparatus, characterized in that the bending amount of the doctor knife is adjusted.