JPS6045949B2 - Comma-shaped doctor knife and its bend adjustment control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a comma-shaped doctor knife used when coating a running web with a coating resin liquid and a bend adjustment control device for the doctor knife.

There are various shapes of doctor knives used in doctor-type coaters, but recently a so-called comma-shaped doctor knife 1, which has an edge part on a part of the roll circumferential surface, has been used as shown in Fig. 1. There is.

In the figure, 2 is a backing roll, 3 is a web of paper, film, etc. wrapped around the backing roll 2 and inserted between the doctor knife 1 and the backing roll 2;
4 is a coating resin liquid applied to the surface of the web 3, and 5 is a gum plate forming a liquid reservoir 6 for the coating resin liquid 4. A coating film 4a is formed on the surface of the web 3 by the doctor knife 1 while the web 3 is running. However, the above-mentioned doctor knife 1 has the problem of bending due to its own weight, and the problem of reverse bending of the doctor knife 1 that occurs when the coating resin liquid 4 pushes up the doctor knife 1 in a wedge shape during coating. occurs. Therefore, the present applicant has already proposed a bend adjustment device as shown in FIGS. 2 and 3 as a means for eliminating the reverse bend that occurs in the doctor knife 1. That is, the doctor knife 1 is composed of a support shaft 7 and a cylindrical doctor knife body 9 that is fitted and held concentrically on the support shaft 7 through members 8, 8. 1 on the outer surface
Edge portions 10 are formed in one or more locations in the longitudinal direction, and screw holes 11 share a center line on both sides of the supporting shaft 7 and the doctor knife main body 9.
, 12 are respectively formed, and a special adjusting nut 13 having threaded portions formed on the inner and outer surfaces is attached to the screw hole 11 on the side of the doctor knife main body 9, and a bolt 14 screwed into the special adjusting nut 13 is used for supporting. It is screwed into a screw hole 12 on the shaft 7 side. If the doctor knife body 9 is bent or reversely bent, the doctor knife body 9 can be lifted upward or pushed down by operating the special adjusting nut 13 to hold it in the proper position. was. However, in this case, the operator would have to visually check the amount of resin liquid 4 applied to the web 3 or the amount of deflection of the doctor knife body 9, and manually operate the special adjustment nut 13 based on this. The drawback was a lack of reproducibility. Further, although the doctor knife main body 9 is formed with a screw hole 11 for connection with the support shaft 7, the presence of the screw hole 11 may cause minute distortions when manufacturing the doctor knife main body 9 or adjusting the bend. may occur, and resin liquid or screw hole 1
There were problems such as the water flowing into the interior through the 1st grade. Furthermore, excessive use of the adjustment device causes distortions to be left in the edge portion 10, which is an important cutting edge, resulting in the problem of uneven coating. In view of the above-mentioned points, the present invention includes a doctor knife body having an edge portion at one or more places on the outer peripheral surface of the roll, which is inserted and held onto a shaft, and a predetermined portion between the doctor knife body and the shaft by appropriate means. air·
A comma-shaped doctor knife interposed with an expandable and contractible pressure vessel through which fluid such as oil flows in and out, and a bend of the doctor knife by expanding or contracting the pressure vessel by fluid pressure based on the changing position of the doctor knife. It is an object of the present invention to provide a bend adjustment control device that allows proper adjustment. The present invention will be described below with reference to embodiments shown in the drawings.

4 to 7, 21 is a comma-shaped doctor knife according to the present invention, 22 is a support shaft that constitutes the doctor knife 21, and this support shaft 22 is rotatably fixed horizontally to the frame 20. Recesses 23a and 2 are provided at opposing portions of the upper and lower circumferential surfaces approximately in the center.
3b is formed.

Reference numeral 24 denotes a cylindrical doctor knife body having an edge portion 25 serving as a cutting edge extending longitudinally at one or more places on the outer circumferential surface. 26 and held concentrically.

27a and 27b are pressure vessels that can be expanded and contracted through which fluids such as air and oil can flow in and out, and these pressure vessels 27a and 27b are thin-walled bags made of metal such as brass or relatively thick-walled rubber. Use a bag etc. made of materials such as

The pressure vessels 27a, 27b are accommodated in the recesses 23a, 23b of the shaft 22 and interposed between the shaft 22 and the doctor knife 24, and are formed within the shaft 22, with one end facing the shaft end surface 24. It is connected to the passages 29a and 29b which are open to each other. 30a and 30b are pipes connected to the passages 29a and 29b of the shaft 22, and these pipes 30a and 30b and the passage 29 of the shaft 22 are
A pipe line 31a through which fluid such as air and oil flows between a and 29b.
, 31b.

32a and 32b are pressure sources connected to one end of the pipe lines 31a and 31b, respectively;
2b uses, for example, a compressor, a pump, or an accumulator.

33a, 33b are, for example, 3-boat, 2-position switching valves provided in the middle of the pipes 30a, 30b, and these switching valves 33a,
33b is switched by a controller to be described later.

Reference numeral 34 denotes a detector for detecting the displacement of the doctor knife body 24 due to its own weight, such as the amount of deflection or reverse bending, and this detector 34 is mounted on the frame 20 in close proximity to the doctor knife body 24.

Reference numeral 35 denotes a controller, and this controller 35 is preset with a value corresponding to the reference position of the doctor knife main body 24, and calculates and processes this set value and the detected value detected by the detector 34. Based on the results, the doctor knife 21
The switching valves 33a, 33 are arranged so that the bending of the doctor knife 21 can be properly adjusted by expanding or contracting the upper and lower pressure vessels 27a, 27b by fluid pressure.
This configuration is configured to output an operation signal for operating b.

In FIGS. 4 and 5, the same reference numerals as in FIG. 1 indicate the same parts. The bend adjustment of the doctor knife 21 is performed in the following manner.

First, before applying the resin liquid 4 to the web 3, a value corresponding to the reference position of the doctor knife body 24 is set to the controller 35.
Set in advance.

The reference position of the doctor knife main body 24 is normally a horizontal position, but this can be changed as appropriate. Then, when coating of the resin liquid 4 is started and a reverse bend occurs in the doctor knife body 24 due to the resin liquid 4 entering in a wedge shape between the doctor knife 21 and the backing 7-rule 2, the changed position is detected. is detected by the device 34. Then, the controller 3
5 performs arithmetic processing on the reference position setting value of the doctor knife body 24 and the detection value of the detector 34, and switches the switching valve 33b so as to appropriately adjust the bending of the doctor knife body 24 based on the result. urge This switching valve 33
By switching b, the fluid in the pressure source 32b flows into the lower pressure vessel 27b through the pipe line 31b and pressurizes the pressure vessel 27b, thereby expanding the pressure vessel 27b until the doctor knife main body 24 bends downward and corrects the bend. When the reverse bend of the doctor knife body 24 is corrected and restored to the reference position, the detector 34 detects the reference position, and the controller 35 outputs a signal to operate the switching valve 33b, and the switching valve 33b is operated. The valve 33b is closed and the doctor knife body 2
4 in the reference position. Further, when the doctor knife main body 24 is bent downward, the amount of the bending is detected by the detector 34.

Then, in the same manner as described above, the controller 35 performs arithmetic processing on the reference position setting value of the doctor knife body 24 and the detection value of the detector 34, and based on the result, the controller 35
The changeover valve 33a is operated to appropriately adjust the deflection of the changeover valve 33a. By switching the switching valve 33a, the fluid in the pressure source 32a is transferred to the upper pressure vessel 27a via the pipe line 31a.
The pressure vessel 27a is expanded until the deflection of the doctor knife body 24 is corrected. When the deflection of the doctor knife body 24 is corrected and restored to the standard position, the detector 34 detects the standard position, and the controller 35 outputs a signal to operate the switching valve 33a. The switching valve 33a is closed and the doctor knife main body 24 is held at the reference position. Furthermore, in order to prevent the doctor knife body 24 from being bent or bent, the controller 35 controls the switching valves 33a, 3.
3b, and each pressure vessel 27a of the Dokuku knife 21
, 27b may be injected with fluid such as air or oil to expand the pressure vessel, thereby holding the doctor knife body 24 horizontally in the form of a rod.

In addition, each pressure vessel 27a of the doctor knife main body 24,
If either one of the blades 27b is pressurized, the other one is depressurized, so that the bend adjustment of the doctor knife 21 can be made more smoothly.

Further, in the above embodiment, the pressure vessels of the doctor knife 21 are provided at the upper and lower center of the doctor knife 21, but the present invention is not limited to this, and the bending or reverse bending of the doctor knife 21 can be effectively controlled. Any location may be used as long as it can be reliably corrected.As explained above, the present invention provides a method for inserting and holding a doctor knife main body having an edge portion at one or more locations on the outer circumferential surface of the roll onto a shaft. A doctor knife is constructed by interposing an expandable and contractible pressure vessel into which fluid such as air or oil flows in and out by appropriate means at a predetermined portion between the main body and the shaft, and further, the pressure is adjusted based on the changed position of the doctor knife. Since the container can be expanded or contracted by fluid pressure to appropriately adjust the bend of the doctor knife, the bend of the doctor knife can be adjusted automatically, accurately and quickly. It has excellent reproducibility and allows the doctor knife to be held horizontally at all times.
In addition, since there is no need to form a screw hole or the like in the doctor knife body as in the conventional case, there will be no distortion of the edge of the doctor knife body during manufacturing or bend adjustment, and uneven coating will not occur. It is possible to completely prevent this, and also to prevent the resin liquid from entering the inside of the doctor knife. Furthermore, it is highly effective in coating wide webs and coating with high viscosity coating liquids.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of a comma-shaped doctor knife, Figures 2 and 3 are conventional comma-type doctor knives, Figure 2 is a front cross-sectional view, and Figure 3 is a partially sectional side view. It is a diagram.

Claims (1)

[Scope of Claims] 1. A doctor knife body having an edge portion at one or more places on the outer peripheral surface of the roll is inserted and held on a shaft, and a predetermined portion between the doctor knife body and the shaft is injected with air or oil by appropriate means. A comma-shaped doctor knife characterized by having an inflatable and deflated pressure vessel inserted into and out of which a fluid such as the like is inserted. 2. A doctor knife body having an edge portion at one or more places on the outer peripheral surface of the roll is inserted and held on the shaft, and a fluid such as air or oil flows in and out of a predetermined portion between the doctor knife body and the shaft by an appropriate means. a comma-shaped doctor knife with an inflatable and deflated pressure vessel interposed therebetween; a pipe line communicating with the pressure vessel of the doctor knife; a pressure source connected to one end of the pipe line; and a pressure source provided in the middle of the pipe line. A value corresponding to the selected switching valve, a detector that detects the displacement amount of the doctor knife, and a reference position of the doctor knife is set in advance, and the set value and the detected value detected by the detector are processed by calculation. and a controller that outputs an operating signal to operate the switching valve so that the pressure vessel of the doctor knife is expanded or contracted by fluid pressure based on the result and the bend of the doctor knife can be adjusted appropriately. Bend adjustment control device for comma-shaped doctor knife.