JP3395424B2 - Die coating equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a die coating apparatus capable of quickly changing paint during a painting operation.

[0002]

2. Description of the Related Art Die coating is a method in which the paint discharged from the die is directly applied to a long object to be coated (die-
There is a direct method) and a method (die-transfer method) in which the coating material discharged from the die is once received by a coating roll and then applied from the coating roll to a long object to be coated. Both methods have many advantages over the conventional roll coating methods, so it is expected that more and more painting will be done by die coating in the future. One of the problems with die coating is that it takes time to switch paints during painting operations. That is, when the paint is changed, the paint must be extracted from the inside of the die and the pipe connected to the die, the die and the pipe are washed with a solvent, and then new paint is supplied from the paint container.

One proposed method of solving this problem is to fit a pig in a manifold so as to be liquid-tight and movable, and to move the pig in the manifold when switching paints. The method is to discharge the paint in the manifold (see Japanese Patent Laid-Open No. 6-47334).
Further, as a method that is a further development of this method, a pair of hollow inners, one end of which is closed and the other end of which is open, and the open end of which has a deckle that fits into the paint flow path from the manifold to the discharge end A method has been proposed in which a shaft is fluid-tightly and movably fitted to a manifold so that the open ends face each other, and a pig is fluid-tightly and movably fitted to the inside of the inner shaft (Japanese Patent Application No. 2000-242242). Flat 5
-262220) To change the paint by this method,
First, move the pair of inner shafts until they come into contact with each other to discharge the paint in the manifold and the paint flow path from the manifold to the discharge end, then move the pig to discharge the paint in the inner shaft. Supply.

[0004]

According to the paint switching method using these pigs, the time required for the paint switching is remarkably shortened, but there is still a point to be improved. One of them is that since the pig is moved by a method of pulling it with a string, an accident of cutting the string occurs. When the string is cut, the die must be disassembled and repaired, which requires a lot of work. Further, such a method of mechanically moving the pig requires a mechanism for moving the pig, which complicates the apparatus.

[0005]

According to the present invention, a pig is moved in a manifold or an inner shaft by fluid pressure of paint or other fluid supplied to a die.
It is intended to avoid the above-mentioned problems associated with the use of mechanical means such as a string. In the method of switching paints using a pig, the pig must be held in a fixed position in the manifold or inner shaft during painting, at the end opposite to the end where the paint is introduced. I have to. This is because if the pig moves during the painting operation, the volume that the paint should occupy inside the die will change, and the discharge speed of the paint from the die will change to compensate for this volume change. In the die coating device, in order to precisely control the thickness of the coating film, the coating material is supplied to the die by an accurate metering pump, and the supplied coating material is entirely discharged from the discharge end. Often. In this case, the above-mentioned volume change significantly impairs the uniformity of the coating film thickness. Also, when the paint is circulated through the die manifold and a part of the paint in the manifold is discharged from the discharge end, the instantaneous volume change causes a pressure change in the manifold, which changes the discharge speed of the paint. there is a possibility. In the conventional method of pulling a pig with a cord, when the cord at the front and rear ends of the pig is tensioned and fixed, the pig is automatically held at a fixed position. However, in the method of driving the pig by fluid pressure, the pig may move if the pressure difference between the front and rear ends of the pig changes.

In the present invention, the movement of the pig during the coating operation can be avoided by fixing by the pressure difference or fixing by mechanical means. In fixing by pressure difference, a locking member that prevents movement of the pig is provided at the end of the manifold or the closed end of the inner shaft, and the pressure applied to both ends of the pig is the pressure applied from the center side of the manifold. The pressure should always be higher than the pressure. In the simplest case, the locking member may also serve as a member that closes the end of the manifold or the inner shaft, in which case the paint supply pipe and the paint discharge pipe are opened in this member. Preferably, the locking member is provided away from the end toward the center of the manifold, and the paint supply pipe and the paint discharge pipe are opened between the end and the locking member. The shape of the locking member is arbitrary as long as it can prevent the movement of the pig toward the terminal side, and may be, for example, a manifold such as the stopper of FIG. 6 or a pin protruding into the inner shaft.

During the painting operation, the supply pressure of the paint used for painting is applied to the end portion of the pig's manifold, which is blocked by the locking member, toward the center of the manifold. On the other hand, the pressure of the solvent for cleaning the paint pipe which is at rest and the pressure of the paint supplied for use in the next coating are applied to the end portion of the pig close to the end. Therefore, keep the pressure applied to the paint pipe in a rest state smaller than the pressure applied to the paint pipe in operation.During the painting operation, the pig is pressed against the locking member due to the pressure difference and fixedly held in that position. It In the fixing by mechanical means, a locking member that detachably engages with the pig is provided at the end of the manifold or the closed end of the inner shaft, and the pig is engaged and fixed during the painting operation. Therefore, even if the pressure difference between both ends of the pig changes during the painting operation, the pig is held by a locking member and cannot move, and is held at a fixed position.

The present invention will be described in more detail with reference to the drawings. FIG. 1 is a perspective view schematically showing the basic structure of a die used in the present invention, in which 1 is an upper plate constituting the die and 2 is a lower plate. It is a plate. Reference numeral 3 is a manifold having a circular cross section formed by an upper plate and a lower plate, and 4 is a paint flow passage extending from the manifold to the discharge end 5. FIG. 2 is a cross-sectional view schematically showing a state in which a pig is fitted in the manifold of the die, 6 is a paint supply pipe to the manifold 3, and 7 is a paint discharge pipe from the manifold. The paint supply pipe and the paint discharge pipe form a pair and open at both ends of the manifold.
Reference numeral 8 is a member for closing the end of the manifold. 9 is a pig that is fitted in a liquid-tight and movable manner in the manifold. Reference numeral 10 is a pig locking member provided at the end of the manifold. Further, pressure air supply / exhaust pipes 11 are opened at both ends of the manifold.

In order to switch the paint of the die of FIG. 2 by the method of the present invention, the paint supply pipe in operation (in FIG. 2, the pig is engaged with the locking member at the left end, the paint is not shown at the right end). Is supplied to the manifold from the paint supply pipe on the right side, and the entire amount is discharged from the discharge end.), And the valve on the paint discharge pipe at the right end is opened, and then the pig is engaged with the locking member. To cancel. Now that the preparation for switching has been completed,
The paint supply pipe at the left end, which is idle, is activated to supply new paint from the paint supply pipe at the left end to the manifold. The pig is pushed by the supply pressure of the paint and moves to the right while removing the paint in the manifold through the paint discharge pipe at the right end. Once the pig has reached the right end locking member, the locking member and pig are engaged to hold the pig in this position. At this point, the manifold is filled with new paint supplied from the supply pipe at the left end, and a part of it flows into the paint flow path 4, and the old paint existing in this part is removed and the manifold is discharged from the discharge end. leak. As a result, the paint inside the die is switched to a new paint, so that the painting work can be continued.

As is clear from the above description, since the pig moves due to the paint supply pressure, the pig must be located closer to the center than the opening of the paint supply pipe at the start of the movement. Therefore, normally, the pig is held at this position by the locking member. By doing this, during the painting work with new paint, the paint in the paint supply pipe and the paint discharge pipe at the right end is discharged, and the inside is washed with a solvent, and in some cases, the paint used for the next painting work is changed. Although the filling work is performed, since the main body of the manifold and the right end portion are blocked by a liquid-tight pig, the preparatory work can be performed without any influence on the painting work.

In a preferred embodiment of the present invention, the pressure gas supply pipe 11 is opened between the both ends of the manifold and the pigs held by being engaged with the locking members. This pressure gas supply pipe is normally closed, but it is used for removing bubbles when, for example, bubbles occur in the manifold and the coating film becomes abnormal. That is, when paint is supplied from the paint supply pipe at the right end and air bubbles are generated in the manifold during painting work, the paint supply pipe in operation at the right end is stopped and the valve of the paint discharge pipe at the right end is opened. ,
Then, the engagement between the pig and the locking member is released. Now that the preparatory work has been completed, the pressure gas supply pipe at the left end is activated to introduce pressure gas into the manifold. The pig is pushed by the pressure gas and moves to the right to discharge the air bubbles together with the paint in the manifold through the paint discharge pipe. When the pig reaches the right end, the supply of the pressure gas is stopped and the valve of the gas discharge pipe is opened (in FIG. 2, the gas passes through a branch pipe (not shown) in the middle of the pressure gas supply pipe 11 to release the gas into the atmosphere). And the paint discharge pipe at the right end is closed,
Reactivate the paint supply pipe at the right end. Since the pig moves to the left again by the pressure of the paint and reaches the locking member, the pig is engaged with the locking member. Since the removal of the air bubbles in the manifold is completed by the above operation, the painting work is subsequently restarted. As is clear from the above description, by moving the pig by the pressure gas, the manifold can be emptied, so that the pressure gas supply pipe is operated even when the painting operation is completed.

FIG. 3 schematically shows an example of an embodiment in which a pair of hollow inner shafts are fitted to a manifold. According to this embodiment, the coating width is changed in addition to the switching of the coating material. Can be done easily. In FIG. 3, reference numeral 12 denotes an inner shaft, and 2 for the manifold.
The inner shafts of the book are fluid-tightly and movably fitted to the manifold so that one end of each of the inner shafts projects from the left and right. A drive mechanism for moving the inner shaft is attached to a portion of the inner shaft protruding from the manifold, but is omitted in the drawing.

FIG. 4 is a perspective view of the inner shaft.
13 is a deckle, and 14 is a support for supporting the deckle. The deckle is made of polytetrafluoroethylene or the like so as to be fluid-tightly fitted to the paint flow path 4 and have a movable thickness. The support is preferably made of metal in order to have strength, and its thickness may be such that it can move in the paint flow path with almost no resistance. Reference numeral 15 is an O-ring provided at the tip of the inner shaft, and the O-ring keeps the inner shaft and the manifold in a liquid-tight state. The O-ring in front of the deckle may be omitted.

FIG. 5 shows a pig and a locking member used in the present invention.
FIG. 6 is a cross-sectional view showing an example and showing a state in which a pig is held by a locking member at the left end portion of the inner shaft. The pig 9 has a shape in which a cylindrical engaging portion 903 having a flange 902 facing inward is attached to a front end and a rear end of a cylindrical main body 901 formed so that liquid does not flow inside. is doing. An O-ring 904 is attached around the main body 901, and the O-ring keeps the inner shaft and the pig liquid-tight. The locking member 10 has an operating rod 10 having a key-like engaging portion 101 at its tip.
The operation rod is rotatably projected from the closed end of the inner shaft. Since the operating rod is installed eccentrically with respect to the center axis of the pig, the engaging portion 101 of the operating rod can be moved to the pig collar 9 by simply rotating the operating rod.
02 can be engaged or disengaged.

As shown in FIG. 5, the end portion of the inner shaft has a slightly larger diameter than the other portions, and the operating rod is installed so that it can be moved forward and backward, and the pig can be drawn into this large diameter portion. Preferably. This is advantageous when coating is started from a state in which no paint is present on the manifold or the inner shaft, such as when the die is disassembled and washed. That is, when the paint is supplied to this large diameter part and then the pig is pulled into the large diameter part by the operating rod, the paint flows from the periphery of the pig into the inner shaft, so this paint adheres to the periphery of the pig and becomes a lubricant. ,
The subsequent movement of the pig can be performed smoothly.

A method of switching the paint when the pig is fitted to the inner shaft will be described (the paint is supplied from the paint supply pipe at the right end portion (not shown) to the manifold through the inner shaft, and the pig is shown in FIG. (It is assumed that the inner shaft is locked to the left end of the inner shaft), first, the paint supply pipe at the right end is stopped, and the valve of the paint discharge pipe at the right end is opened. The left and right inner shafts are moved to bring them into contact with each other at the center of the die, new paint is supplied from the paint supply pipe at the left end, and the pig is moved to the right end by the pressure of the paint. When the pig reaches the right end side, the pig is locked by the locking member. By the above operation, the old paint in the inner shaft is almost completely removed, but some old paint may remain in the inner shaft and the deckle butting part, the gap between the inner shaft and the manifold, and the like. In order to remove the remaining old paint, it is preferable to perform an operation of pulling the abutted inner shafts left and right and abutting them again, or an operation of moving the inner shafts left and right with the abutting inner shafts. When the old paint is completely removed by these operations, the inner shaft is moved to the left and right so as to be at an interval corresponding to a predetermined application width and fixed, and the painting work is performed.

FIG. 6 shows another example of engagement between the detachable locking member and the pig. In this example, engaging portions 903 having annular grooves are attached to the front and rear of the pig main body 901. And a wedge-shaped locking member 10 that fits in this annular groove
However, it is provided so that it can move back and forth through the tube wall of the inner shaft. Reference numeral 16 is a stopper for surely stopping the pig at a position where it engages with the locking member.

[0018]

According to the present invention, since the pig is moved by the fluid pressure, the mechanism is simple and the failure is unlikely to occur as compared with the method of mechanically moving the pig.

[Brief description of drawings]

FIG. 1 is a perspective view showing a basic structure of a die used in the present invention.

FIG. 2 is a diagram schematically showing a cross-sectional state of the manifold end portion when a pig is fitted to the manifold according to the present invention.

FIG. 3 is a diagram schematically showing a state of the closed end portion of the inner shaft when the inner shaft is fitted to the manifold and the pig is fitted to the inner shaft according to the present invention.

FIG. 4 is a perspective view of an inner shaft used in the present invention.

FIG. 5 is a view showing an example of a pig and a locking member used in the present invention in a state where the pig is locked to the closed end portion of the inner shaft.

FIG. 6 is a view showing another example of the pig and the locking member used in the present invention in a state where the pig is locked to the closed end portion of the inner shaft.

[Explanation of symbols]

1 die top plate 2 die bottom plate 3 manifold 4 paint flow path 5 Discharge end 6 Paint supply pipe 7 Paint discharge pipe 8 Manifold end closure 9 pigs 10 Pig locking member 11 Pressure air supply-exhaust pipe 12 Inner shaft 13 Deckel 14 Deckel's support 15 O-ring 16 stopper

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Claims (5)

(57) [Claims] 1. A manifold having both ends closed, and a flat paint flow path connecting the manifold and the paint discharge end,
In a die coating apparatus having a paint supply pipe and a paint discharge pipe open at both ends of a manifold, a pig is fitted in a liquid-tight and movable manner, and a pig is fitted at both ends of the manifold. And a locking member that locks the pig by detachably engaging with the pig, and is configured so that the pig can be positioned closer to the center of the manifold than the opening of the paint supply pipe. apparatus. 2. A manifold, a flat paint flow path that connects the manifold and a paint discharge end, and a movably fitted to the manifold, the end near the center of the manifold is open, and the other end is closed. A pair of hollow inner shafts and a means for moving these inner shafts, each inner shaft being fluid-tightly fitted to the manifold at the open end, and each inner shaft being opened. In a die coating device where a deckle that fits into the paint flow path is attached to the end and a paint supply pipe and a paint discharge pipe are open at the closed end, the pig is liquid-tight and moves on the inner shaft. Each inner shaft is fitted with a locking member that detachably engages with the pig to lock the pig. The apparatus is configured such that the pig can be positioned closer to the center of the manifold than the opening of the paint supply pipe. 3. Between the end of the manifold or the closed end of the inner shaft and the pig locked by the locking member,
The device according to claim 1 or 2, wherein the device is configured to be capable of supplying a pressure gas from the outside. 4. A cylinder having a cylindrical main body in which a liquid does not pass through and a liquid-tight fit to a manifold or an inner shaft, and a collar portion connected to both ends of the main body and facing inward. The engaging member is a rod-shaped member whose end is formed in a key shape so as to engage with the flange of the pig, and the engaging member is the end of the manifold or the inner shaft. 4. The device according to claim 1, wherein the device is mounted so as to be rotatable from the closed end of the same so as to be eccentrically and substantially parallel to these central axes. 5. The end portion of the manifold or the closed end portion of the inner shaft is thicker than the other portions, and the locking member is configured so that the pig can be drawn into the thickened portion. 5. A method according to claim 1, wherein
The device according to any one of 1.