JP2013188696A - Coating valve and coating system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating valve that can keep film thickness uniformity of a coating film formed to a coating object.SOLUTION: A coating valve includes: a valve box 31 that communicates to a coating head 2 for discharging a coating liquid to a coating object; a valve seat 31a that is provided in the valve box 31 and has an opening 31b which allows the passage of a coating liquid; and a shaft 32 that extends to penetrate through the opening 31b and can move toward the coating head 2. The shaft 32 includes: a valve body 33 that is provided at an end of the shaft 32 and can open and close the opening 31b; a cavity 34 that is provided with an inlet 35a enclosed with the valve body 33 at the end and an outlet 35b communicating in the valve box 31 at a part different from the end, and extends along the axial direction of the shaft 32 inside the shaft 32; and a check valve 36 that is provided at the outlet 35b and opens the outlet 35b only in a direction toward the outside of the shaft from the cavity.

Description

  The present invention relates to a coating valve that controls the supply of a coating liquid from a tank to a coating head, and a system including the coating valve.

  A coating system is known in which a coating film is formed on a metal foil by coating a coating solution on the metal foil that is one of the objects to be coated (see Patent Document 1). FIG. 9 is a diagram showing a configuration of a coating system related to the present invention. In the coating system 100 shown in FIG. 9, the coating liquid 160 stored in the tank 110 is fed to the coating valve 130 by the pump 140 and then supplied to the coating head 120. Thereafter, when the transport roller 150 is transporting the metal foil 170, the coating head 120 discharges the coating liquid from the slit 121 onto the metal foil 170. In the coating system 100, the coating valve 130 controls the supply of the coating liquid 160 from the tank 110 to the coating head 120. Hereinafter, the operation content of the application valve 130 will be described with reference to FIG.

  FIG. 10 is a diagram showing the operation content of the application valve 130 shown in FIG. As shown in FIG. 10, at the start of application, the valve body 133 provided at the tip of the shaft 132 is in contact with a valve seat 131 a formed inside the valve box 131. At this time, in the application valve 130, the application liquid does not leak from the gap between the valve box 131 and the shaft 132 by the seal member 134. Inside the valve box 131, the coating liquid cannot pass through the valve seat 131a because the valve body 133 contacts the valve seat 131a. That is, the valve body 133 blocks the supply of the coating liquid to the coating head 120. Thereafter, in the initial state, the shaft 132 starts to rise by the drive source 136 connected to the shaft 132 via the joint block 135. As the shaft 132 is lifted, the valve body 133 is separated from the valve seat 131a. Therefore, the coating liquid flows into the coating head 120 through the valve seat 131a. Subsequently, the coating head 120 discharges the coating solution onto the metal foil 170, whereby the formation of the coating film 180 starts. Thereafter, in a steady state, the shaft 132 continues to rise until the tip end of the shaft 132 reaches the position closest to the coating head 120 (position where the valve body 133 is farthest from the valve seat 131a), and is stationary at the position. In a steady state, the coating liquid is ejected from the coating head 120 at a constant speed, so that the thickness of the coating film 180 is kept uniform. Thereafter, in the final state, the drive source 136 lowers the shaft 132, and then the shaft 132 is in the same state as at the start of application at the end of application.

JP2011-194329A

  In the application valve 130 described above, as shown in FIG. 11, when the shaft 132 is raised (when the valve seat 131a is opened), the application liquid is applied inside the valve box 131 by the tip of the shaft 132 and the valve body 133. A pressure that pushes toward the head 120 is generated. When this pressure is large, the coating liquid is rapidly pushed out to the coating head 120. As a result, there is a possibility that a phenomenon in which the film thickness is increased in the initial stage of forming the coating film, so-called overshoot (see FIG. 12). When overshoot occurs, the uniformity of the coating film thickness is impaired.

  Therefore, an object of the present invention is to provide a coating valve capable of maintaining the uniformity of the thickness of a coating film formed on a coating target, and a coating system including the coating valve.

  In order to achieve the above object, an application valve of the present invention comprises a valve box communicating with an application head for discharging the application liquid onto an object to be applied, and an opening through which the application liquid can pass inside the valve box. And a shaft that extends through the opening and is movable toward the coating head. The shaft is provided at a tip of the shaft and opens and closes the opening. A possible valve body, an inlet surrounded by the valve body at the tip, and an outlet communicating with the inside of the valve box at a location different from the tip, the inside of the shaft being an axis of the shaft A cavity extending along a direction, and a check valve provided at the outlet and opening the outlet only in a direction from the cavity toward the outside of the shaft.

  In order to achieve the above object, the coating system of the present invention is supplied from the coating valve, a tank that supplies the coating liquid to the coating valve, and the tank that communicates with the tank via the coating valve. An application head for discharging the application liquid onto an object to be applied.

  According to the present invention, it is possible to maintain the uniformity of the thickness of the coating film formed on the coating object.

It is a figure which shows the structure of the coating system of Embodiment 1 of this invention. It is a figure which shows the structure of the application | coating valve | bulb shown in FIG. FIG. 3 is a cross-sectional view showing a state where the check valve closes the outlet in the application valve shown in FIG. 2. It is a figure which shows the operation | movement content of the application | coating valve | bulb shown in FIG. It is a figure which shows the operation | movement content of the application | coating valve | bulb shown in FIG. It is a figure which shows the structure of the application | coating valve | bulb of Embodiment 2 of this invention. It is a figure which shows the structure of the application | coating valve | bulb of Embodiment 3 of this invention. It is sectional drawing which shows the other form of the shaft of an application | coating valve | bulb. It is a figure which shows the structure of the coating system relevant to this invention. It is a figure which shows the operation | movement content of the application | coating valve | bulb shown in FIG. It is a figure which shows the mode inside the valve box at the time of the raise of the application | coating valve | bulb shown in FIG. It is a graph for demonstrating overshoot.

(Embodiment 1)
A first embodiment of the present invention will be described. FIG. 1 is a diagram illustrating a configuration of a coating system according to the first embodiment. In the coating system 10 shown in FIG. 1, the coating liquid 6 is stored in the tank 1. The coating liquid 6 is fed to the coating valve 3 by the pump 4 and then supplied to the coating head 2. The coating head 2 discharges the coating liquid from the slit 21. In front of the discharge direction of the coating liquid, the metal foil 7 that is the object to be coated is transported by the transport roller 5. When the transport roller 5 is transporting the metal foil 7, the coating head 2 discharges the coating liquid onto the metal foil 7, whereby a coating film 8 is formed on the metal foil 7. In the coating system 10, the coating valve 3 controls the supply of the coating liquid 6 from the tank 1 to the coating head 2. Hereinafter, the configuration and operation of the application valve 3 will be described.

  First, the configuration of the application valve 3 will be described. FIG. 2 is a diagram showing a configuration of the application valve 3 shown in FIG. In the application valve 3 shown in FIG. 2, the application liquid 6 stored in the tank 1 flows into the valve box 31 through the inflow path 9a. On the other hand, the coating liquid stored in the valve box 31 flows out to the coating head 2 through the outflow path 9b. A valve seat 31 a is formed inside the valve box 31. The valve seat 31a has an opening 31b.

  Inside the valve box 31, the coating liquid flowing from the tank 1 is supplied to the coating head 2 after passing through the opening 31b of the valve seat 31a. The opening 31 b is opened and closed by the valve body 33. The valve body 33 is provided at the tip of the shaft 32. The shaft 32 extends through the valve box 31 to the outside of the valve box 31. The application valve 3 is provided with a seal portion 37 so that the application liquid does not leak from the gap between the valve box 31 and the shaft 32. The rear end of the shaft 32 is connected to a drive source 39 by a joint block 38. The drive source 39 is composed of, for example, an air cylinder or a motor.

  A hollow portion 34 is formed inside the shaft 32. The hollow portion 34 includes an inlet 35 a surrounded by the valve element 33 at the distal end portion of the shaft 32 and an outlet 35 b formed on the outer peripheral portion of the shaft 32, and the inside of the shaft 32 extends along the axial direction of the shaft 32. It extends. The outlet 35b opens at the outer periphery of the shaft 32, and is further away from the application head 2 than the valve seat 31a. The outlet 35b is opened and closed by a check valve 36. FIG. 3 is a cross-sectional view showing a state where the check valve 36 shown in FIG. 2 closes the outlet 35 b in a cross section perpendicular to the axial direction of the shaft 32. The check valve 36 opens the outlet 35 b only in the direction from the cavity 34 toward the outside of the shaft 32.

  Next, the operation of the application valve 3 will be described. 4 and 5 are diagrams showing the operation contents of the application valve 3 shown in FIG.

  At the start of application shown in FIG. 4A, the valve element 33 is in contact with the valve seat 31a. Therefore, the coating liquid cannot pass through the opening 31 b inside the valve box 31. That is, the valve body 33 blocks the supply of the coating liquid to the coating head 2.

  After the start of application shown in FIG. 4A, in the initial state shown in FIG. 4B, the drive source 39 raises the shaft 32 in the moving direction A. As the shaft 32 moves up, the valve element 33 moves from the valve seat 31 a toward the application bed 2. By this movement, the coating liquid passes through the opening 31b and starts to flow toward the coating bed 2 side. At this time, since the inlet 35a is formed at the tip of the shaft 32 and the cavity 34 is formed inside the shaft 32, a part of the coating liquid flows into the cavity 34 from the inlet 35a. The applied coating liquid flows in the cavity 34 in the direction opposite to the moving direction A. Then, the internal pressure of the cavity 34 increases due to the flow pressure of the coating liquid. When the internal pressure becomes larger than the flow pressure of the coating liquid flowing inside the valve box 31, the check valve 36 opens the outlet 35b. As a result, the coating liquid that has flowed into the cavity 34 returns from the outlet 35 b to the inside of the valve box 31.

  After the initial state shown in FIG. 4 (b), in the steady state shown in FIG. 4 (c), the shaft 32 is located at the tip end closest to the application head 2 (the valve body 33 is farthest from the valve seat 31a). It keeps rising until it reaches (position) and is stationary at that position. In a steady state, the coating liquid is applied from the coating head 2 at a constant speed, so that the film thickness of the coating film 8 is kept uniform. Furthermore, since the internal pressure of the cavity 34 becomes smaller than the flow pressure of the coating liquid flowing inside the valve box 31 due to the stationary shaft 32, the check valve 36 closes the outlet 35b.

  After the steady state shown in FIG. 4C, in the final state shown in FIG. 5A, the drive source 39 starts to lower the shaft 32. Thereafter, at the end of application shown in FIG. 5 (b), the valve element 33 comes into contact with the valve seat 31a and the check valve 36 closes the outlet 35b as in the initial state (see FIG. 4 (a)). Yes.

  According to the first embodiment, since the inlet 35a is formed at the tip of the shaft 32, the area of the pressing surface that pushes the coating liquid when the shaft 32 is raised is smaller than that of the coating valve 130 (see FIG. 9). . Further, a hollow portion 34 having an inlet 35a and an outlet 35b is formed inside the shaft, and a check valve 36 is provided outside the outlet 35b. Therefore, as the shaft 32 moves up, the coating liquid flows into the cavity 34 from the inlet 35a. As a result, the internal pressure of the cavity 34 increases. As the internal pressure increases, the check valve 36 opens the outlet 35b. The coating liquid returns to the inside of the valve box 31 by opening the outlet 35b. Therefore, the pressure for pushing the coating liquid toward the coating head 2 when the shaft 32 is raised is relaxed compared to the coating valve 130. As a result, it is possible to avoid a situation in which the coating liquid is suddenly pushed out to the coating head 2, so that it is possible to maintain the uniformity of the thickness of the coating film 8.

(Embodiment 2)
A second embodiment of the present invention will be described. The coating system of Embodiment 2 has the same configuration as the coating system 10 of Embodiment 1 except for the coating valve. Hereinafter, a description will be given centering on differences from the first embodiment. FIG. 6 is a diagram illustrating a configuration of a coating valve according to the second embodiment. The same components as those of the application valve 3 of Embodiment 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the application valve 13 illustrated in FIG. 6, the shaft 32 includes the cylindrical member 14, the rod-shaped member 15, and the connecting member 16. A valve body 33 is provided at the distal end of the cylindrical member 14, and an inlet 35 a surrounded by the valve body 33 is formed. A hollow portion 34 is formed inside the cylindrical member 14. The cavity 34 includes an inlet 35a and an outlet 35b formed at the rear end of the tubular member 14. The rod-shaped member 15 is located behind the tubular member 14 in the movement direction A of the shaft 32, penetrates the valve box 32, and extends to the outside of the valve box 32. The rod-like member 15 is connected to a drive source 39 by a joint block 38 outside the valve box 32. The connecting member 16 is a hollow member for connecting the rod-like member 15 to the tubular member 14. One end of the connecting member 16 is attached to the outer peripheral portion of the cylindrical member 14. The other end of the connecting member 16 is attached to the outer periphery of the rod-like member 15. A circular hole 17 passes through the central portion of the connecting member 16. A check valve 36 is fixed to the inner surface of the hole 17.

  In Embodiment 2, when the drive source 39 raises the shaft 32, a part of the coating liquid flows from the inlet 35a into the cavity 34 and flows out from the outlet 35b through the cavity 34. Thereafter, the coating liquid that has flowed out passes through the hole 17 of the connecting member 16 and returns to the inside of the valve box 32.

  According to the second embodiment, as in the first embodiment, the pressure of pushing the coating liquid toward the coating head 2 when the shaft 32 is lifted is reduced compared to the coating valve 130. Accordingly, it is possible to avoid a situation in which the coating liquid is pushed out to the coating head 2 abruptly, so that the uniformity of the coating film 8 can be maintained.

  In the second embodiment, as shown in FIG. 6, there are two connection members 16 that face each other with the cylindrical member 14 and the rod-shaped member 15 interposed therebetween, but the present invention is not limited to this form. For example, in order to make it easy to return the coating liquid flowing out from the outlet 35b to the inside of the valve box 32 (to ensure many flow paths), the connecting member 16 continuously or intermittently connects the cylindrical member 14 and the rod-shaped member 15. A plurality of them may be installed so as to surround them.

(Embodiment 3)
Embodiment 3 of the present invention will be described. The coating system of Embodiment 3 has the same configuration as the coating system 10 of Embodiment 1 except for the coating valve. Hereinafter, a description will be given centering on differences from the first embodiment. FIG. 7 is a diagram illustrating a configuration of a coating valve according to the third embodiment. The same components as those of the application valve 3 of Embodiment 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The application valve 23 shown in FIG. 7 has a configuration in which a packing member 18 is added to the application valve 3 (see FIG. 2) of the first embodiment. In the application valve 3 of the first embodiment, when the gap between the valve body 33 and the valve seat 31a before ascending is large, the application liquid leaks from the gap and the flow is not sufficiently blocked. Further, in the application valve 3, when the shaft 32 starts to rise, the application liquid may vigorously pass through the opening 31b, so that the application liquid having a large flow rate may temporarily flow into the application head 2. In this case, the uniformity of the coating film 8 may be impaired.

  Therefore, in the third embodiment, the packing member 18 functions as a means for more reliably closing the opening 31b by being positioned in the gap between the valve body 33 and the valve seat 31a before being raised. Further, when the drive source 39 raises the shaft 32, the packing member 18 is displaced to a position away from the raised valve body 33 and the valve body 33 by the fluid pressure of the coating liquid passing through the opening 31b. Therefore, the packing member 18 functions as a means for suppressing the flow of the coating liquid even when the coating liquid passes through the opening 31b vigorously. Therefore, since the situation where the coating liquid having a large flow rate temporarily flows into the coating head 2 can be avoided, the coating head 23 is less likely to lose the uniformity of the film thickness of the coating film 8 than the coating head 3. Become.

  The present invention has been described above with reference to the embodiments, but the present invention is not limited to the above embodiments.

  In the present invention, in order to ease the pressure for pushing the coating liquid toward the coating head 2 when the shaft 32 is lifted and to facilitate the flow of the coating liquid to the cavity 34, the cavity 34 has a shaft 32 as shown in FIG. 8. The opening may have a shape in which the opening width increases as it approaches the entrance 35a. The cavity 34 shown in FIG. 8A can be formed, for example, by obliquely chamfering the corner on the inlet 35a side of the valve body 33 shown in FIG. On the other hand, the cavity 34 shown in FIG. 8B can be formed, for example, by chamfering the corner on the inlet 35a side of the valve body 33 shown in FIG. 2 into a rounded shape.

1, 110 Tank 2, 120 Coating head 3, 13, 23, 130 Coating valve 4, 140 Pump 5, 150 Transport roller 6, 160 Coating solution 7, 170 Metal foil 8, 180 Coating film 9a Inflow path 9b Outflow path 10, DESCRIPTION OF SYMBOLS 100 Application system 14 Cylindrical member 15 Bar-shaped member 16 Connecting member 17 Hole 18 Packing member 21, 121 Slit 31, 131 Valve box 31a, 131a Valve seat 31b Opening 32, 132 Shaft 33, 133 Valve body 34 Cavity 35a Inlet 35b Outlet 36 Check valve 37, 134 Seal part 38, 135 Joint block 39, 136 Drive source

Claims (6)

A valve box communicating with the application head for discharging the application liquid onto the object to be applied;
A valve seat having an opening through which the coating liquid can pass inside the valve box;
A shaft extending through the opening and movable toward the application head,
The shaft is
A valve body provided at the tip of the shaft and capable of opening and closing the opening;
An inlet surrounded by the valve body at the distal end and an outlet communicating with the interior of the valve box at a location different from the distal end, the interior of the shaft extending along the axial direction of the shaft A hollow portion,
A check valve provided at the outlet and opening the outlet only in a direction from the cavity toward the outside of the shaft.   2. The application valve according to claim 1, wherein the outlet is opened at an outer peripheral portion of the shaft and is located on a rear side in a moving direction of the shaft with respect to the valve seat. The shaft is
A tubular member provided with the valve body and the cavity,
A rod-shaped member that is separated from the tubular member rearward in the movement direction of the shaft, extends through the valve box to the outside of the valve box, and is connected to the drive source of the shaft outside the valve box;
A connecting member having one end attached to the outer peripheral portion of the cylindrical member and the other end attached to the outer peripheral portion of the rod-shaped member, and the connecting member has a hole penetrating the central portion of the connecting member A connecting member in which the check valve is fixed to the hole,
The coating valve according to claim 1, comprising:   The packing member is further displaceable between a position sandwiched in a gap between the valve seat and the valve body before movement, and a position away from the valve seat and the valve body after movement. 4. The coating head according to any one of items 1 to 3.   The coating head according to any one of claims 1 to 4, wherein the hollow portion has a shape in which an opening width is widened from the inside of the shaft toward the inlet. An application valve according to any one of claims 1 to 5,
A tank for supplying a coating liquid to the coating valve;
An application head that communicates with the tank via the application valve and discharges the application liquid supplied from the application valve to an application object;
A coating system.

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