JP2000084452A - Apparatus for supplying coating liquid to plate cylinder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the defective application of coating liquid on a sheet by changing the amount of the coating liquid adherent to the surface of a plate cylinder by changing the level of the coating liquid in the liquid bank of a chamber. SOLUTION: A transparent window 71 over a prescribed height range is formed on the rear surface side of a chamber 30, and a liquid level sensor 72 for detecting the height H of a liquid level in a liquid bank 31 through the window 71 is installed. A supply pump 50 for supplying a coating liquid to the bank 31 of the chamber 30 is controlled corresponding to the detected value of the sensor 72, and the height H of the liquid level in the bank 31 is kept within a prescribed range.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating liquid supply apparatus for supplying a coating liquid such as a coating agent or ink to a plate cylinder such as a coating roll or a printing plate cylinder in a coating machine or a gravure printing machine. .

[0002]

2. Description of the Related Art FIG. 4 shows an apparatus for applying a coating liquid to a sheet material such as a conventional coating machine or gravure printing machine.

In this coating apparatus, a sheet material S is pressed from above onto a plate surface 11 of a plate cylinder 10 such as a coating roll or a printing plate cylinder by an impression cylinder 20, and the coating material adhered to the plate surface 11 on the surface of the sheet material S. And a coating liquid such as ink or ink.

A coating liquid supply device for supplying a coating liquid to the plate surface 11 of the plate cylinder 10 includes a chamber 30 disposed at a side position of the plate cylinder 10 and a coating liquid tank 60 for storing the coating liquid.
And a supply pipe 41 for feeding the coating liquid from the coating liquid tank 60 to the chamber 30 via the feed pump 50, and a return pipe 42 for returning the coating liquid from the chamber 30 to the coating liquid tank 60. ing.

In the chamber 30, the plate surface 1 of the plate cylinder 10 is provided.
A liquid reservoir 31 that opens to face 1 is formed, and the supply conduit 41 and the return conduit 42 communicate with a lower portion and an upper portion of the liquid reservoir 31, respectively. The seal plate 32 provided at the lower end of the opening of the liquid reservoir 31 seals the space between the lower end of the opening of the liquid reservoir 31 and the printing plate 11, and the doctor blade 33 provided at the upper end of the opening. This removes the excess coating liquid adhering to the plate surface 11.

In such a coating liquid supply apparatus,
In a normal operation state, the amount of the coating solution supplied from the supply line 41 to the chamber 30 via the supply pump 50, the amount of the coating solution adhered to the plate surface 11 of the plate cylinder 10, and the amount of the coating solution discharged from the return line 42. The sum of the amounts of the coating liquids balances, and the liquid surface height H of the coating liquid in the liquid pool 31 is maintained at a predetermined height position.

[0007]

However, in such a coating liquid supply apparatus, changes in the temperature and pressure of the working environment, changes in the viscosity of the coating liquid, malfunctions in the supply pump 50, supply pipes 41, The balance between the amount of the coating liquid supplied to the chamber 30 and the amount of the coating liquid discharged to the chamber 30 is lost due to a cause such as clogging of the discharge pipe 42, and the liquid surface height H of the coating liquid in the liquid pool 31 is easily changed. .

However, when the liquid surface height H of the coating liquid in the liquid pool 31 is excessively reduced in this way, the contact area where the plate surface 11 of the rotating plate cylinder 10 and the coating liquid come into contact in the chamber 30 is increased. Is reduced, the plate surface 11 leaves the chamber 30 without sufficient coating liquid being applied,
There is a problem in that a coating liquid is poorly applied to the sheet material S.

Further, in such a coating apparatus, even in a normal operation state, some air bubbles 91 enter between the plate surface of the plate cylinder 10 and the seal plate 32 due to being caught by the rotation of the plate cylinder 10, When the liquid surface height H of the coating liquid in the reservoir 31 rises excessively and the liquid reservoir 31 is filled with the coating liquid, such bubbles are light and easily return from the return line 42. Most of the liquid is not discharged, but is discharged from the liquid pool 31 through the contact portion between the doctor blade 33 and the plate surface 11. For this reason, if the liquid surface height H of the coating liquid in the liquid pool 31 rises excessively, the plate surface 11 of the plate cylinder 10 that has exited the chamber 30 will be in a state where many air bubbles have adhered, and the coating liquid Since the adhesion unevenness occurs, there is a problem that a coating liquid is poorly applied to the sheet material S.

The present invention has been made in view of such a problem, and has as its object to provide a coating liquid supply apparatus for a plate cylinder which can prevent the coating liquid from being defectively applied to a sheet material. .

[0011]

In order to solve the above-mentioned problems, a coating liquid supply apparatus for a plate cylinder according to the present invention includes a plate cylinder having a coating liquid applied to a surface of a sheet material. A chamber installed along the plate surface, an opening facing the plate surface of the plate cylinder, a liquid reservoir formed in the chamber, an upper port communicating with an upper portion of the liquid reservoir, and an upper port communicating with the liquid reservoir. A lower mouth communicating with the lower part,
A coating liquid tank in which a coating liquid is stored, a coating liquid supply means for supplying the coating liquid in the coating liquid tank to the liquid pool of the chamber from the lower port, and a coating liquid in the liquid pool of the chamber. The liquid supply apparatus further includes a return pipe returning from the upper port to the application liquid tank, and a liquid level detecting means for detecting a liquid level in the liquid pool (claim 1).

With such a liquid level detecting means,
Failure to apply the coating liquid to the sheet material can be detected because abnormalities in the liquid level of the coating liquid in the liquid pool, which causes insufficient adhesion or uneven adhesion of the coating liquid to the plate surface of the plate cylinder, can be detected. Can be prevented beforehand.

[0013] Such a liquid level detecting means is provided on a side wall of the chamber over a predetermined height range so that the liquid level in the liquid reservoir can be visually recognized from outside the chamber. It is desirable to provide a window (claim 2).

If such a transparent window is provided, the operator can easily detect the liquid level in the liquid pool from outside the chamber by visual observation. It becomes easy to prevent the occurrence of coating failure of the coating liquid on the material.

[0015] Further, such a liquid level height detecting means includes:
It is preferable that the apparatus further includes a liquid level sensor for detecting the liquid level of the coating liquid stored in the liquid reservoir from outside the chamber through the transparent window (claim 3).

If a liquid level sensor for detecting the liquid level of the coating liquid stored in such a liquid pool from outside the chamber is provided, the liquid level sensor directly contacts the coating liquid. Since the application liquid does not adhere to the liquid level detection sensor, it is possible to prevent a detection failure from occurring, and thus to reliably prevent the application failure of the application liquid from occurring on the sheet material. .

The apparatus for supplying a coating liquid to a plate cylinder according to the present invention comprises: a chamber provided along a plate surface of the plate cylinder at a side position of the plate cylinder for applying a coating liquid to a surface of a sheet material; A liquid reservoir formed in the chamber having an opening facing the plate surface of the plate cylinder, an upper port communicating with an upper part of the liquid reservoir, a lower port communicating with a lower part of the liquid reservoir, and a coating liquid. A coating liquid tank to be stored, a coating liquid supply means for supplying the coating liquid in the coating liquid tank to the liquid pool of the chamber from the lower port, and a coating liquid in the liquid pool of the chamber from the upper port. A return line for returning to the coating liquid tank, and a return flow rate detecting means for detecting a flow rate of the coating liquid flowing in the return line are provided (claim 4).

In such a coating liquid supply apparatus, a predetermined amount of the coating liquid always passes through the return pipe if the normal liquid level of the coating liquid is maintained in the liquid reservoir of the chamber. On the contrary, if the flow rate of the coating liquid flowing through the return line is abnormal because it is returned to the tank, it is determined that the normal liquid level is not maintained in the liquid pool of the chamber. sell.

Therefore, according to the coating liquid supply device of the present invention provided with the return flow rate detecting means, the return flow rate detecting means detects the flow rate of the coating liquid flowing through the return pipe, thereby providing the plate surface of the plate cylinder. It is possible to detect abnormalities in the liquid level of the coating liquid in the liquid pool, which may cause insufficient adhesion of the coating liquid or uneven adhesion to the coating liquid, thereby preventing the coating liquid from being defectively applied. Can be.

Such a return flow detecting means is provided on at least a part of the peripheral wall of the return pipe so that the flow rate of the coating solution flowing in the return pipe can be visually recognized from outside the return pipe. It is desirable to provide a transparent window (claim 5).

If such a transparent window is provided, the operator can visually detect the flow rate of the coating solution flowing from outside the return line to inside the return line. It is easy to prevent the application failure of the application liquid from occurring on the sheet material due to the occurrence of the abnormalities in the sheet material.

Further, it is preferable that such a return flow detecting means includes a return flow detecting sensor for detecting a flow rate of the coating liquid flowing through the return conduit through the transparent window from outside the return conduit ( Claim 6).

If a return flow sensor is provided for detecting the flow rate of the coating solution flowing in the return pipe from outside the return pipe, the return flow sensor comes into direct contact with the coating liquid and Since the application liquid does not adhere to the flow rate detection sensor, it is possible to prevent the detection failure from occurring, and it is possible to reliably prevent the application failure of the application liquid from occurring on the sheet material.

Further, when at least one of the liquid level detecting means and the return flow rate detecting means is provided, the liquid level of the coating liquid in the liquid pool detected by the liquid level detecting means is detected. Adjusting the flow rate of the coating liquid supplied to the liquid pool in the chamber in accordance with the height or the flow rate of the coating liquid flowing through the return line detected by the flow rate detecting means; It is desirable to have a coating liquid supply amount control means for controlling the liquid supply means.

The liquid level detecting means directly detects the liquid level in the liquid pool, and the return flow rate detecting means detects the return flow rate to indirectly detect the liquid level in the liquid pool. Is detected. Therefore, the application liquid supply amount control means for adjusting the flow rate of the application liquid supplied to the liquid pool via the application liquid supply means according to the liquid level in the liquid pool detected by these detection means. If provided, for example, when the liquid level in the liquid pool is abnormally rising, reduce the flow rate of the coating liquid supplied to the liquid pool, and conversely, when the liquid level is abnormally low. By increasing the flow rate of the coating liquid supplied to the liquid pool, the liquid level in the liquid pool can always be maintained at a desired level, whereby an appropriate amount of the coating liquid is always applied to the plate surface of the plate cylinder. , And the desired coating liquid can be applied to the sheet material.

When the flow rate of the coating liquid to be supplied to the liquid reservoir in the chamber is adjusted in accordance with the liquid level in the liquid reservoir, the coating liquid supply means may apply the coating liquid to the chamber. An air-driven pump that sucks up from a liquid tank and supplies the liquid reservoir of the chamber from the lower port, an air source that supplies compressed air to the air-driven pump, and a supply from the air source to the air-driven pump A regulator capable of adjusting the pressure of the compressed air to be supplied, wherein the application liquid supply amount control means controls the flow rate of the application liquid supplied to the liquid reservoir in the chamber by controlling the regulator. It is desirable (claim 8).

In this way, the coating liquid is fed by an air-driven pump, thereby preventing the coating liquid from being ignited even when a flammable coating liquid is used, thereby achieving high safety. By adjusting the pressure of the compressed air supplied to the air-driven pump while adjusting the pressure by the regulator, the flow rate of the application liquid supplied to the liquid pool can be adjusted with high accuracy.

[0028]

FIG. 1 shows an example of a coating apparatus having a coating liquid supply apparatus for a plate cylinder according to the present invention. The same components as those of the conventional apparatus shown in FIG. 4 are denoted by the same reference numerals.

As shown in this figure, the coating apparatus presses a sheet material S made of paper or a plastic film from above onto a plate surface of a plate cylinder 10 such as a coating roll or a printing plate cylinder by an impression cylinder 20. The coating liquid such as a coating agent or ink adhered to the plate surface 11 is transferred onto the surface of the sheet material S.

A coating liquid supply device for supplying a coating liquid to the plate surface 11 of the plate cylinder 10 includes a chamber 30 disposed at a side position of the plate cylinder 10 and a coating liquid tank 60 for storing the coating liquid.
A supply pipe 41 for supplying the coating liquid from the coating liquid tank 60 to the chamber 30, a feed pump 50 for supplying the coating liquid in the supply pipe 41, and the coating liquid from the chamber 30 to the coating liquid tank 60. Return line 42,
43 and the like. Reference numeral 15 denotes a receiving tray for receiving a dripping of the application liquid.

A liquid level detection sensor 72, which will be described later, is attached to the rear side wall of the chamber 30, and a controller 90 which receives an output signal from the sensor 72 or the like is provided with a regulator 52 or the like which will be described later. , The supply pump 50 is operated to adjust the flow rate of the coating liquid supplied to the chamber 30.

FIG. 2 is a side sectional view of the coating apparatus.

As shown in this figure, a recess provided in the chamber 30 so as to face the plate cylinder 10 forms a liquid reservoir 31 for storing a coating liquid therein. The return line 42 communicates with a lower portion and an upper portion of the liquid reservoir 31, respectively.

A seal plate 32 made of a plastic plate or the like is provided at the lower end of the front surface of the liquid reservoir 31, that is, on the upstream side in the rotation direction of the plate cylinder 10 so as to face the rotation direction of the plate cylinder 10. The lower end of the front surface of the liquid reservoir 31 is sealed by pressing the tip of the seal plate 32 against the plate surface 11 of the plate cylinder 10.

Further, at the upper end of the front surface of the liquid reservoir 31, that is, at the downstream side in the rotation direction of the plate cylinder 10, the plate cylinder 10
A doctor blade 33 made of a stainless steel plate, a steel plate, or the like is provided so as to face the rotation direction, and the tip of the doctor blade 33 is pressed against the plate surface 11 of the plate cylinder 10 so that the liquid pool is formed. The upper end of the front surface of the printing plate 31 is sealed, and the printing plate 1
The excess coating liquid adhering to 1 is scraped off by the doctor blade 33.

FIG. 3 shows the liquid pool 3 in the chamber 30.
1 is a sectional perspective view showing the inside of FIG.

As shown in this figure, a transparent window 71 made of transparent or translucent tempered glass, plastic, or the like is provided over a predetermined height range on the rear side wall of the chamber 30 (FIG. 1). , FIG. 2).

In this apparatus, by providing such a transparent window 71 in the chamber 30, an operator can visually detect the liquid level H in the liquid pool of the chamber 30 from outside the chamber 30, and It can be checked whether or not the liquid level H is abnormal. Therefore, it is possible to prevent the occurrence of an application failure on the sheet material due to the occurrence of an abnormality in the liquid level H beforehand. Therefore, it is possible to prevent the occurrence of an application failure on the sheet material S due to an abnormality in the liquid level H.

Further, on the outer surface side of the transparent window 71, an optical detection sensor such as a photoelectric switch for detecting the liquid level H of the liquid pool in the chamber from outside the chamber 30 through the transparent window 71. The liquid level height detection sensor 72 is attached.

By providing such a liquid level height detecting sensor 72, the apparatus automatically detects the liquid level height H even when the operator does not visually confirm the liquid level height H. In addition, it is possible to prevent the occurrence of an application failure on the sheet material S due to the occurrence of an abnormality in the liquid level H beforehand.

Since the liquid level detecting sensor 72 detects the liquid level inside the reservoir 31 from outside the chamber 30 through the transparent window 71, the liquid level detecting sensor 72 does not come into direct contact with the coating liquid. Therefore, the detection accuracy does not decrease due to the application liquid adhering.

Returning to FIG. 1, the return conduit for returning the coating solution to the coating solution tank 60 of the chamber 30 is
Two return conduits 42, 42 extending one by one from the left and right sides of the upper part, and the two return conduits 4;
2 and 42 are formed from one return conduit 43 that joins behind the chamber 30. This return line 4
Of the parts 2, 43, the parts 42, 42 on the upstream side of the position where the conduits join are constituted by transparent tubes made of transparent or translucent plastic or the like. That is,
The entire surfaces of the return pipes 42, 42 are configured as transparent windows, and the flow rate of the coating solution flowing through the return pipes 42, 42 can be visually detected by the operator from outside the return pipes 42, 42. It has become.

The flow rate of the coating solution flowing through the return lines 42, 42 is affected by the liquid surface height H in the liquid reservoir 31 of the chamber 30. By detecting the flow rate of the coating liquid flowing through the chamber 30, it is possible to estimate the liquid level H in the liquid pool 31 of the chamber 30. Therefore, in this apparatus, since the flow rate of the coating liquid flowing through the return pipes 42, 42 can be detected, the liquid level height in the liquid reservoir 31 of the chamber 30 can be determined from the return flow rate thus detected. H can be detected indirectly. Therefore, in this apparatus, even if the flow rate of the coating liquid flowing through the return pipes 42, 42 is detected, it is possible to prevent the defective application of the sheet material S from occurring due to the abnormality in the liquid level height H. Can be prevented.

Further, since the flow rate of the coating solution flowing through the return pipes 42, 42 can be visually confirmed, even if the return flow rate is abnormal, the cause of the abnormality is the return pipe. It is possible to determine whether or not clogging occurs in the roads 42, 42.

On the other hand, from the coating solution tank 60 to the chamber 3
The supply pump 50 for feeding the application liquid to the liquid reservoir of No. 0 is constituted by an air-driven pump operated by compressed air supplied from an air source 51.

Therefore, even when the coating liquid is a coating agent containing flammable ink or adhesive, the coating liquid is supplied by the supply pump 50 composed of an air-driven pump that does not easily generate high heat or sparks. Therefore, the coating liquid is prevented from igniting and extremely high safety can be obtained.

The compressed air supplied from the air source 51 can be adjusted to a desired pressure on the flow path of the compressed air sent from the air source 51 to the supply pump 50 composed of the air-driven pump. A regulator 52;
A pressure sensor 53 for detecting the air pressure in the flow path downstream of the regulator 52 on the flow path, and an air gauge 54 for an operator to check the air pressure in the flow path are arranged.

By providing such a pressure sensor 53, the airtight state of the compressed air flow path and the air source 51
It is possible to detect whether the operation of the supply pump 50 has an abnormality due to an abnormality in the operation of the supply pump 50, and whether an abnormality has occurred in the amount of the coating liquid supplied to the chamber 30, and to prevent such an abnormal state. I can do it.

The regulator 52 for adjusting the pressure of the compressed air sent to the supply pump 50 is controlled by a controller 90. The controller 90 includes the pressure sensor 53 and the liquid pool in the chamber 30. A detection signal is input from the liquid level detection sensor 72 for detecting the liquid level H in the inside 31.

The controller 90 to which the detection signal of the liquid level detecting means 72 is input as described above, supplies the supply pump according to the liquid level H in the liquid reservoir 31 detected by the liquid level detecting sensor 72. By controlling the regulator 52 to control the air pressure supplied to the nozzle 50, for example, the liquid level H
Is abnormally high, the air pressure sent to the supply pump 50 is reduced to reduce the flow rate of the coating liquid supplied to the chamber 30, thereby lowering the liquid level H in the liquid reservoir 31. Conversely, when the liquid level H is abnormally low, the air pressure sent to the supply pump 50 is increased to increase the flow rate of the application liquid supplied to the chamber 30 so as to increase the liquid pool 31. The liquid level height H inside is increased.

That is, the controller 90 adjusts the amount of the coating liquid supplied to the liquid pool 31 of the chamber 30 in accordance with the detection value of the liquid level detection means (liquid level detection sensor) 72. The controller 90 maintains the liquid level height H in the liquid pool 31 within a predetermined height range in this manner.
In this way, the amount of the coating liquid adhering to the plate surface 0 can be stabilized, and a desired coating state on the sheet material S can be obtained.

The appropriate range of the liquid level H in the liquid reservoir 31 depends on the configuration of the entire coating liquid coating apparatus including the coating liquid supply apparatus, the temperature and pressure of the working environment, the viscosity of the coating liquid, and the like. Thus, the amount of the coating liquid adhering to the plate surface 11 of the plate cylinder 10 may be appropriately set within an appropriate range. In general, when the rotation operation of the plate cylinder 10 is stopped, the plate surface 11 of the plate cylinder 10 is stopped. It can be said that the height range centered on the vicinity of the contact position between the blade and the doctor blade 33 is a proper range of the general liquid level height H.

Although the present invention has been described with reference to the embodiment, the coating liquid supply apparatus for the plate cylinder according to the present invention is not limited to the above embodiment, and may be configured as follows. Good.

(1) In the above embodiment, the return pipes 42, 42 are formed of a transparent member so that the operator can visually detect the flow rate of the coating solution flowing through the return pipes 42, 42. As shown in the figure, a return flow rate detection sensor including an optical detection switch for detecting the flow rate of the coating solution flowing through the return pipes 42 from outside the return pipes 42 is provided. May be input to the controller 90 to control the liquid level H in the liquid reservoir 11 of the chamber. In this case, the controller 90 controls the application liquid supply means (the regulator 52, the supply pump 50, etc.) even when used together with the liquid level detection sensor 72 in the above-described embodiment, or only by the detection of the return flow rate detection sensor. You may do so.

(2) In the above embodiment, the coating liquid supply means for supplying the coating liquid to the chamber 30 is provided by the air source 5.
Although it is constituted by an air-driven pump (supply pump) 50 operated by air from 1, any component such as an electric pump or a hydraulic pump can be used as long as it is a component capable of supplying the coating liquid from the coating liquid tank 60 to the chamber 30. Known supply means may be used.

(3) In the above embodiment, the liquid level sensor 72 for detecting the liquid level of the liquid reservoir 31 in the chamber 30 is provided through the transparent window 71 through the transparent window 71.
Although the configuration using the optical switch for detecting the liquid level from outside 0 has been described, any known detecting means may be used as long as the detecting means can detect the liquid level H in the chamber 30. For example, the liquid level detecting means may be constituted by a sensor or the like for detecting the liquid level H while directly contacting the coating liquid in the liquid pool 31.

[0057]

As described above, according to the present invention, since the liquid level detecting means for detecting the liquid level in the liquid reservoir in the chamber is provided, the amount of the coating liquid adhering to the plate surface of the plate cylinder is provided. By detecting an abnormality in the liquid level in the liquid pool which causes the fluctuation of the sheet material, it is possible to prevent the occurrence of coating failure on the sheet material beforehand.

Further, according to the structure provided with the return flow rate detecting means for detecting the flow rate of the coating liquid flowing through the return pipe, the flow rate of the coating liquid flowing through the return pipe is detected to indirectly detect the flow rate of the coating liquid flowing through the return pipe. Since the liquid level height in the liquid pool can be detected, the liquid level height in the liquid cylinder is detected in the same manner as in the case where the liquid level height in the liquid pool is directly detected by the liquid level height detecting means described above. It is possible to prevent the application amount of the applied coating liquid from fluctuating and the sheet material from being defectively applied.

Further, there is provided a coating liquid supply amount control means for adjusting the amount of the coating liquid supplied to the liquid pool in accordance with the liquid level in the liquid pool detected by the liquid level height detecting means and the return flow rate detecting means. With this arrangement, it is possible to maintain the liquid level in the liquid reservoir at a predetermined level and prevent the sheet material from being defectively applied.

[Brief description of the drawings]

FIG. 1 is an overall schematic view showing an embodiment of a coating liquid supply device for a plate cylinder according to the present invention.

FIG. 2 is a side sectional view of the same device.

FIG. 3 is an explanatory sectional view of a chamber 30 part of the apparatus.

FIG. 4 is a side view of a conventional coating liquid supply device for a plate cylinder.

[Description of Signs] 10 plate cylinder 11 plate surface 20 impression cylinder 30 chamber 31 liquid reservoir 32 seal plate 33 doctor blade 41 supply line 42 return line (transparent part) 43 return line 50 supply pump (air-driven pump; coating) Liquid supply means) 51 Air source 52 Regulator 60 Coating liquid tank 71 Transparent window (Liquid level detecting means) 72 Liquid level detecting sensor (Liquid level detecting means) 90 Controller (Coating liquid supply amount controlling means)

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Takahiro Mizuno 2-3-17, Shigeyin, Fuchu-cho, Aki-gun, Hiroshima Prefecture F-term in Fuji Machine Industry Co., Ltd. 4F040 AA22 AC01 BA35 CC02 CC08 CC14 DA02 DA12

Claims (8)

[Claims] A chamber provided along a plate surface of the plate cylinder at a side position of the plate cylinder for applying a coating liquid to a surface of a sheet material; and an opening facing the plate surface of the plate cylinder. A liquid reservoir formed in the chamber, an upper port communicating with an upper portion of the liquid reservoir, a lower port communicating with a lower portion of the liquid reservoir, a coating liquid tank for storing a coating liquid, A coating liquid supply means for supplying a coating liquid to the liquid pool of the chamber from the lower port, a return pipe returning the coating liquid in the liquid pool of the chamber from the upper port to the coating liquid tank, and the liquid A coating liquid supply device for a plate cylinder, comprising: a liquid level detection means for detecting a liquid level in a reservoir. 2. A transparent surface provided on a side wall of the chamber over a predetermined height range so that the liquid level detecting means can visually check the liquid level in the liquid reservoir from outside the chamber. The coating liquid supply device for a plate cylinder according to claim 1, further comprising a window. 3. The liquid level detecting means includes a liquid level detecting sensor for detecting the liquid level of the coating liquid stored in the liquid reservoir from outside the chamber through the transparent window. An apparatus for supplying a coating liquid to a plate cylinder according to claim 2. 4. A chamber provided along a plate surface of the plate cylinder at a side surface position of a plate cylinder for applying a coating liquid to a surface of a sheet material, and an opening facing the plate surface of the plate cylinder. A liquid reservoir formed in the chamber, an upper port communicating with an upper portion of the liquid reservoir, a lower port communicating with a lower portion of the liquid reservoir, a coating liquid tank for storing a coating liquid, A coating liquid supply means for supplying the coating liquid to the liquid reservoir of the chamber from the lower port, a return pipe returning the coating liquid in the liquid reservoir of the chamber from the upper port to the coating liquid tank, and the return A coating liquid supply device for a plate cylinder, comprising: a return flow rate detecting means for detecting a flow rate of a coating liquid flowing in a pipe. 5. The return flow rate detecting means is provided on at least a part of a peripheral wall of the return pipe so that a flow rate of a coating solution flowing in the return pipe can be visually recognized from outside the return pipe. The coating liquid supply device for a plate cylinder according to claim 4, further comprising a transparent window. 6. The return flow rate detecting sensor according to claim 5, wherein the return flow rate detecting means includes a return flow rate detection sensor for detecting a flow rate of the coating liquid flowing through the return line from outside the return line through the transparent window. A coating liquid supply device for the plate cylinder. 7. The liquid level of the coating liquid in the liquid pool detected by the liquid level height detecting means, or the flow rate of the coating liquid flowing through the return line detected by the flow rate detecting means. The coating liquid supply amount control means for controlling the coating liquid supply means so as to adjust the flow rate of the coating liquid supplied to the liquid pool of the chamber according to the above. A coating liquid supply device for the plate cylinder described in the above. 8. An air-driven pump for sucking a coating liquid from the coating liquid tank and supplying the liquid to the liquid reservoir of the chamber from the lower port, and applying compressed air to the air-driven pump. An air source to be supplied, and a regulator capable of adjusting a pressure of compressed air supplied from the air source to the air-driven pump, wherein the application liquid supply amount control unit controls the regulator to control the chamber. 8. The apparatus according to claim 7, wherein a flow rate of the application liquid supplied to said liquid reservoir is controlled.
A coating liquid supply device for the plate cylinder described in the above.