Patent Publication Number: US-2022212225-A1

Title: Intermittent valve and intermittent coating apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is the U.S. National Phase under 35 U.S.C. § 371 of International Patent Application No. PCT/JP2020/017612, filed on Apr. 24, 2020, which in turn claims the benefit of Japanese Application No. 2019-112617, filed on Jun. 18, 2019, the entire disclosures of which applications are incorporated by reference herein. 
    
    
     BACKGROUND 
     Field of the Invention 
     The present invention relates to an intermittent valve and an intermittent coating apparatus. 
     Description of the Related Art 
     In recent years, shipments of secondary batteries have been increasing with the spread of electric vehicles (EV), hybrid vehicles (HV), plug-in hybrid vehicles (PHV), and the like. In particular, shipments of lithium-ion secondary batteries are increasing. A general secondary battery has a positive electrode plate, a negative electrode plate, a separator, and an electrolytic solution as main components. Electrode plates such as positive electrode plates and negative electrode plates have a structure in which an electrode active material is stacked on the surface of a current collector made of metal foil. 
     Conventionally, as a method for manufacturing such electrode plates, a method is known that is for intermittently applying an electrode slurry to the surface of long metal foil using an intermittent coating apparatus including: a die for discharging an electrode slurry in which an active material and a solvent are mixed; and an intermittent valve for switching between supply and non-supply of the electrode slurry to the die (see, for example, Patent Literature 1). 
     Patent Literature: Japanese Patent Application Publication No. 2006-51407 
     In order to improve the quality of a secondary battery, it is unsurprisingly required to improve the accuracy of applying an electrode slurry in intermittent coating. Meanwhile, as the shipment of secondary batteries increases, there is a demand for shortening the manufacturing time of electrode plates. However, if an electrode slurry is intermittently applied to metal foil at high speed in order to shorten the manufacturing time of an electrode plate, the accuracy of applying the electrode slurry may be lowered. 
     SUMMARY OF THE INVENTION 
     In this background, a purpose of the present invention is to provide a technology for improving the accuracy of applying a coating material in intermittent coating. 
     One embodiment of the present invention relates to an intermittent valve that switches between supply and non-supply of a coating material from a tank for storing the coating material to a die for applying the coating material to a coating target. This intermittent valve includes: a valve main unit having therein: an inflow chamber that has an upstream end, a first downstream end, and a second downstream end in which the tank is connected to the upstream end; a supply chamber that is connected to the first downstream end and the die; and a return chamber that is connected to the second downstream end and the tank; a piston that is capable of switching between a first position and a second position in the valve main unit; a supply valve that is fixed to the piston, allows the coating material to flow from the inflow chamber to the supply chamber when the piston is in the first position, and blocks the flow when the piston is in the second position; and a return valve that is fixed to the piston, blocks the coating material from flowing from the inflow chamber to the return chamber when the piston is in the first position, and allows the flow when the piston is in the second position, wherein the valve diameter of the supply valve is 1.53 times or more the valve diameter of the return valve. 
     Another embodiment of the present invention relates to an intermittent coating apparatus. This intermittent coating apparatus includes: a tank that stores a coating material; a die that applies the coating material to a coating target; and the intermittent valve according to the above embodiment that switches between supply and non-supply of the coating material to the die. 
     Optional combinations of the aforementioned constituting elements, and implementations of the invention in the form of methods, apparatuses, and systems may also be practiced as additional modes of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       Embodiments will now be described, by way of example only, with reference to the accompanying drawings which are meant to be exemplary, not limiting, and wherein like elements are numbered alike in several Figures, in which: 
         FIG. 1  is a schematic diagram of an intermittent coating apparatus according to an embodiment; and 
         FIG. 2  is a cross-sectional view schematically showing an intermittent valve. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Hereinafter, the present invention will be described based on preferred embodiments with reference to the drawings. The embodiments do not limit the invention and are shown for illustrative purposes, and not all the features described in the embodiments and combinations thereof are necessarily essential to the invention. The same or equivalent constituting elements, members, and processes illustrated in each drawing shall be denoted by the same reference numerals, and duplicative explanations will be omitted appropriately. 
     The scales and shapes shown in the figures are defined for convenience&#39;s sake to make the explanation easy and shall not be interpreted limitatively unless otherwise specified. Terms like “first”, “second”, etc., used in the specification and claims do not indicate an order or importance by any means unless specified otherwise and are used to distinguish a certain feature from the others. Those of the members that are not important in describing the embodiment are omitted from the drawings. 
       FIG. 1  is a schematic diagram of an intermittent coating apparatus according to an embodiment. An intermittent coating apparatus  1  includes a die  2 , an intermittent valve  4 , a tank  6 , a pump  8 , a feed line  10 , a return line  12 , and a die supply line  14 . 
     The die  2  is an instrument for applying a coating material  18  to a coating target  16 . The intermittent coating apparatus  1  according to the present embodiment is used for manufacturing an electrode plate of a secondary battery. The electrode plate of a secondary battery is a sheet-shaped electrode material obtained by applying an electrode slurry to a current collector and then drying the electrode slurry. Therefore, in the present embodiment, the coating target  16  is a current collector of the secondary battery, and the coating material  18  is the electrode slurry of the secondary battery. The current collector is, for example, metal foil. The electrode slurry is, for example, a mixture of a positive electrode active material or a negative electrode active material and a solvent. In the case of a commonly-used lithium ion secondary battery, a positive electrode plate is produced by applying a slurry containing a positive electrode active material such as lithium cobalt oxide or lithium iron phosphate on aluminum foil. Further, the electrode plate of the negative electrode is produced by applying a slurry containing a negative electrode active material such as graphite on copper foil. 
     The die  2  is arranged such that a discharge port  84  faces the peripheral surface of a backup roll  20  at a predetermined distance. The coating target  16  is continuously conveyed to a position where the backup roll  20  and the discharge port  84  face each other by the rotation of the backup roll  20 . 
     The intermittent valve  4  is connected to the die  2  via the die supply line  14 . The intermittent valve  4  is a mechanism for switching between supply and non-supply of the coating material  18  to the die  2 . While the coating material  18  is being supplied to the die  2 , the intermittent coating apparatus  1  can discharge the coating material  18  from the die  2  to the coating target  16 . The tank  6  is connected to the intermittent valve  4  via the feed line  10  and the return line  12 . 
     The tank  6  stores the coating material  18 . The pump  8  is provided in the feed line  10 , and the coating material  18  is sent from the tank  6  to the intermittent valve  4  by the driving of the pump  8 . The intermittent valve  4  supplies the coating material  18  supplied from the tank  6  to the die  2  via the die supply line  14 . Alternatively, the intermittent valve  4  returns the coating material  18  supplied from the tank  6  to the tank  6  via the return line  12 . 
     The intermittent valve  4  supplies the coating material  18  to the die  2 . Thereby, the coating material  18  can be discharged from the die  2  so as to form a coated part  18   a  with the coating material  18  on the coating target  16 . Further, the intermittent valve  4  returns the coating material  18  to the tank  6 . Thereby, the discharge of the coating material  18  from the die  2  can be stopped so as to form an uncoated part  16   a  without the coating material  18  on the coating target  16 . In other words, the intermittent valve  4  allows for intermittent application of the coating material  18  to the coating target  16 . The uncoated part  16   a  is used for attaching the center lead of an electrode or the like. 
       FIG. 2  is a cross-sectional view schematically showing the intermittent valve  4 . The intermittent valve  4  includes a valve main unit  22 , a piston  24 , a supply valve  26 , and a return valve  28 . The valve main unit  22  is a so-called cylinder, has a first opening  30  through which the piston  24  is slidably inserted on the upper surface, and has a second opening  32  to which the feed line  10  is connected, a third opening  34  to which the return line  12  is connected, and a fourth opening  36  to which the die supply line  14  is connected on the side surface. In the explanation of the present embodiment, for convenience, the first opening  30  is provided on the upper surface and the second opening  32  through the fourth opening  36  are provided on the side surface. However, the orientation of the intermittent valve  4  is not particularly limited. 
     Further, the valve main unit  22  has an inflow chamber  38 , a supply chamber  40 , and a return chamber  42  in the inside thereof. The inflow chamber  38  is a substantially T-shaped chamber in which one end part side is branched into two and has an upstream end  38   a , a first downstream end  38   b , and a second downstream end  38   c . The feed line  10  is connected to the upstream end  38   a  via the second opening  32 . In other words, the tank  6  is connected to the upstream end  38   a . The coating material  18  flows into the inflow chamber  38  from the upstream end  38   a  and flows toward the first downstream end  38   b  and the second downstream end  38   c  in the inflow chamber  38 . 
     The supply chamber  40  is connected to the first downstream end  38   b . The die supply line  14  is connected to the supply chamber  40  via the fourth opening  36 . That is, the supply chamber  40  is connected to the die  2 . The coating material  18  that has flowed through the inflow chamber  38  and reached the first downstream end  38   b  flows to the die  2  via the supply chamber  40  and the die supply line  14 . Therefore, the inflow chamber  38  and the supply chamber  40  form a part of the flow path of the coating material  18  connecting the tank  6  and the die  2 . 
     The return chamber  42  is connected to the second downstream end  38   c . The return line  12  is connected to the return chamber  42  via the third opening  34 . That is, the return chamber  42  is connected to the tank  6 . The coating material  18  that has flowed through the inflow chamber  38  and reached the second downstream end  38   c  flows into the tank  6  via the return chamber  42  and the return line  12 . Therefore, the inflow chamber  38  and the return chamber  42  form a part of the flow path through which the coating material  18  circulates between the tank  6  and the intermittent valve  4 . 
     The first opening  30  of the valve main unit  22 , a first connecting part  44  connecting the first downstream end  38   b  and the supply chamber  40 , and a second connecting part  46  connecting the second downstream end  38   c  and the return chamber  42  are arranged to be lined up on a straight line. The first opening  30 , the second connecting part  46 , and the first connecting part  44  are disposed in the order stated. The piston  24  is a rod-shaped member, and one end side thereof is inserted into the first opening  30 , the second connecting part  46 , and the first connecting part  44 . 
     The supply valve  26  is fixed near the first connecting part  44  of the piston  24 . The return valve  28  is fixed near the second connecting part  46  of the piston  24 . The supply valve  26  and the return valve  28  are arranged such that the distance between the supply valve  26  and the return valve  28  in the axial direction X of the piston  24  (the direction in which the axial center of the piston  24  extends) is wider than the distance between the first connecting part  44  and the second connecting part  46 . The supply valve  26 , the return valve  28 , the opening of the first connecting part  44 , and the opening of the second connecting part  46  according to the present embodiment are each circular when viewed from the axial direction X. 
     The piston  24  is capable of switching between a first position and a second position in the valve main unit  22  by being displaced in the axial direction X with respect to the valve main unit  22 . The piston  24  is in the first position when the piston  24  enters the valve main unit  22  further inside compared to when the piston  24  is in the second position and is in the second position when the piston  24  exits the valve main unit  22  further outside compared to when the piston  24  is in the first position. In  FIG. 2 , the piston  24 , the supply valve  26 , and the return valve  28  at the second position are shown by solid lines. Further, the supply valve  26  and the return valve  28  when the piston  24  is in the first position are shown by broken lines. 
     When the piston  24  is in the first position, a gap is formed between the supply valve  26  and the first connecting part  44 , allowing the inflow chamber  38  and the supply chamber  40  to communicate with each other. On the other hand, when the piston  24  is in the second position, the supply valve  26  fits into the first connecting part  44 , blocking the inflow chamber  38  and the supply chamber  40 . Therefore, the supply valve  26  allows the coating material  18  to flow from the inflow chamber  38  to the supply chamber  40  when the piston  24  is in the first position and blocks the coating material  18  from flowing from the inflow chamber  38  to the supply chamber  40  when the piston  24  is in the second position. 
     Further, when the piston  24  is in the first position, the return valve  28  fits into the second connecting part  46 , blocking the inflow chamber  38  and the return chamber  42 . On the other hand, when the piston  24  is in the second position, a gap is formed between the return valve  28  and the second connecting part  46 , allowing the inflow chamber  38  and the return chamber  42  to communicate with each other. Therefore, the return valve  28  blocks the coating material  18  from flowing from the inflow chamber  38  to the return chamber  42  when the piston  24  is in the first position and allows the coating material  18  to flow from the inflow chamber  38  to the return chamber  42  when the piston  24  is in the second position. 
     Therefore, the intermittent valve  4  is in a first state of supplying the coating material  18  to the die  2  when the piston  24  is in the first position and is in a second state of stopping the supply of the coating material  18  to the die  2  when the piston  24  is in the second position. More specifically, since the piston  24  is in the first position when the intermittent valve  4  is in the first state, the inflow chamber  38  and the supply chamber  40  communicate with each other, and the inflow chamber  38  and the return chamber  42  are blocked. Therefore, the coating material  18  that has flowed from the feed line  10  into the inflow chamber  38  is supplied to the die  2  via the supply chamber  40  and the die supply line  14 . On the other hand, since the piston  24  is in the second position when the intermittent valve  4  is in the second state, the inflow chamber  38  and the supply chamber  40  are blocked, and the inflow chamber  38  and the return chamber  42  communicate with each other. Therefore, the coating material  18  that has flowed from the feed line  10  into the inflow chamber  38  is returned to the tank  6  via the return chamber  42  and the return line  12 . 
     The piston  24  is switched between the first position and the second position by a drive unit (not shown) connected to an end part protruding outside the valve main unit  22 . The drive unit includes a motor such as a servomotor and a crank mechanism or the like that connects the motor and the piston  24 . The drive unit may be a publicly-known drive source other than a motor such as an air cylinder. 
     When the piston  24  is displaced from the first position to the second position, the piston  24  moves in the direction in which the piston  24  exits the supply chamber  40 . Therefore, the volume of the portion of the piston  24  located in the supply chamber  40  is reduced. Thereby, the pressure inside the supply chamber  40  becomes negative, and a part of the coating material  18  flows back from the die  2 . Further, when the supply valve  26  is displaced in the direction in which the supply valve  26  approaches the first connecting part  44  due to the displacement of the piston  24 , a part of the coating material  18  is drawn toward the inflow chamber  38  by the supply valve  26 . This also causes a part of the coating material  18  to flow back from the die  2 . Due to the backflow of the coating material  18 , it is possible to prevent the coating material  18  from dripping from the discharge port  84  when the discharge of the coating material  18  from the die  2  is stopped. That is, a suck back effect can be obtained. 
     In the present embodiment, the dimension of the supply valve  26  is larger than the dimension of the return valve  28 . Specifically, the valve diameter D 1  of the supply valve  26  is 1.53 times or more the valve diameter D 2  of the return valve  28 . In other words, the ratio of the valve diameter D 1  of the supply valve  26  to the valve diameter D 2  of the return valve  28  (D 1 /D 2 , this ratio is appropriately referred to as a valve diameter ratio hereinafter) is 1.53 or more. The valve diameter ratio is preferably 1.81 or more and more preferably 2.00 or more. In the present embodiment, the valve diameters D 1  and D 2  of the respective valves are the sizes of the portions of the respective valves having the largest dimension in the direction orthogonal to the axial direction X of the piston  24 . 
     By setting the dimensions of the supply valve  26  and the return valve  28  such that the valve diameter ratio is 1.53 or more, the amount of coating material  18  drawn back from the die  2  by the suck back effect (hereinafter, this amount is appropriately referred to as a suck back amount) can be increased so as to suppress the scattering of the coating material  18  on the uncoated part  16   a.    
     The present inventors performed intermittent coating using each of an intermittent valve according to a reference example having a valve diameter ratio of about 1.52 and an intermittent valve  4  according to an exemplary embodiment having a valve diameter ratio of 2.00. Then, in the reference example and the exemplary embodiment, the amount (area) of the coating material  18  scattered on the uncoated part  16   a  was measured by a publicly-known image analysis, and both were compared. As a result, it was confirmed that when the amount of the coating material  18  scattered on the uncoated part  16   a  in the reference example was set to 1, the amount of the coating material  18  scattered in the exemplary embodiment was reduced to 0.67. 
     Further, using the intermittent valve according to the reference example, the present inventors set the flow rate (flow velocity) of the coating material  18  to 3.2 L/min and performed intermittent coating. Further, using the intermittent valve  4  according to the exemplary embodiment, the flow rate of the coating material  18  was set to 4.0 L/min, and the intermittent coating was performed. As a result, in the intermittent coating using the intermittent valve according to the reference example, scattering of the coating material  18  on the uncoated part  16   a  was observed. On the other hand, in the intermittent coating using the intermittent valve  4  according to the exemplary embodiment, it was confirmed that the amount of the coating material  18  scattered was reduced as compared with the reference example even though the flow rate was increased. The suck back amount in the intermittent valve according to the reference example was 0.17 mL, and the suck back amount in the intermittent valve  4  of the exemplary embodiment was 0.22 mL. 
     In general, as the flow velocity of the coating material  18  increases, the resistance to displacement of the piston  24  from the first position to the second position increases. Therefore, the supply valve  26  is difficult to close, and the coating material  18  is likely to be scattered on the uncoated part  16   a . In spite of such a tendency, according to the present embodiment, it is possible to increase the suck back amount so as to suppress the scattering of the coating material  18  on the uncoated part  16   a . The present inventors recognizes that the suck back amount can be increased and the scattering of the coating material  18  can be suppressed if the valve diameter ratio is set to be larger than at least that of the reference example, that is, if the valve diameter ratio is set to be 1.53 or more. 
     Further, the supply valve  26  according to the present embodiment has a first flat part  26   a  extending in a direction orthogonal to the axial direction X of the piston  24  on a surface facing the first downstream end  38   b  side. Further, the valve main unit  22  has a second flat part  22   a  that comes into surface contact with the first flat part  26   a  when the piston  24  is in the second position. The first flat part  26   a  and the second flat part  22   a  are located outside the first downstream end  38   b  when viewed from the axial direction X. Further, the first flat part  26   a  faces upward, and the second flat part  22   a  faces downward such that the first flat part  26   a  and the second flat part  22   a  face each other. 
     By providing the first flat part  26   a , when the piston  24  is displaced from the first position to the second position, more coating material  18  can be drawn toward the inflow chamber  38  side. As a result, the suck back amount can be increased more reliably. Further, when the first flat part  26   a  and the second flat part  22   a  come into surface contact with each other while the piston  24  is in the second position, the leakage of the coating material  18  from the inflow chamber  38  to the supply chamber  40  can be suppressed. 
     Further, when the piston  24  is displaced from the second position to the first position, a narrow (therefore with a large flow path resistance) flow path is formed that is defined by the first flat part  26   a  and the second flat part  22   a  on the outer periphery of the first downstream end  38   b . Thereby, it is possible to suppress a large amount of coating material  18  from flowing from the inflow chamber  38  into the supply chamber  40  at the moment when the piston  24  is displaced from the second position to the first position. Further, when the piston  24  is displaced from the second position to the first position, the first flat part  26   a  can receive the hydraulic pressure of the coating material  18  flowing out from the inflow chamber  38  to the supply chamber  40 . This allows the supply valve  26  to follow the displacement of the piston  24  with higher accuracy. As a result, the supply and non-supply of the coating material  18  to the die  2  can be switched with higher accuracy. 
     Further, the supply valve  26  has a convex part  26   b  protruding toward the first downstream end  38   b  side in a region closer to the piston  24  than the first flat part  26   a  on the surface facing the first downstream end  38   b  side. While the piston  24  is in the second position, the convex part  26   b  fits into the first downstream end  38   b . Thereby, the leakage of the coating material  18  from the inflow chamber  38  to the supply chamber  40  can be further suppressed. 
     Further, at the outer edge part of the surface facing the first downstream end  38   b  side, the supply valve  26  has a taper part  26   c  that is tapered so as to be spaced apart from the second flat part  22   a  toward the outside of the supply valve  26  in a direction orthogonal to the axial direction X. In the intermittent valve  4  according to the present embodiment, the height position of the second opening  32  and the height position of the fourth opening  36  are substantially aligned. Therefore, the supply chamber  40  extends horizontally from the first connecting part  44 , then extends upward at a position deviated from the piston  24 , and becomes connected to the fourth opening  36 . Therefore, when the valve diameter D 1  of the supply valve  26  becomes large, the outer edge part of the supply valve  26  may project toward the center side of the supply chamber  40  at a spot where the supply chamber  40  bends in the vertical direction from the horizontal direction, obstructing the flow of the coating material  18 . On the other hand, by providing the taper part  26   c , it is possible to reduce the obstructing of the flow of the coating material  18  in the supply chamber  40  caused by the supply valve  26 . 
     As explained above, the intermittent valve  4  according to the present embodiment is a mechanism for switching between supply and non-supply of the coating material  18  from the tank  6  for storing the coating material  18  to the die  2  for applying the coating material  18  to the coating target  16 . The intermittent valve  4  includes a valve main unit  22 , a piston  24 , a supply valve  26 , and a return valve  28 . The valve main unit  22  has therein: an inflow chamber  38  that has an upstream end  38   a , a first downstream end  38   b , and a second downstream end  38   c  in which a tank  6  is connected to the upstream end  38   a ; a supply chamber  40  that is connected to the first downstream end  38   b  and the die  2 ; and a return chamber  42  that is connected to the second downstream end  38   c  and the tank  6 . The piston  24  is capable of switching between the first position and the second position in the valve main unit  22 . The supply valve  26  is fixed to the piston  24 , allows the coating material  18  to flow from the inflow chamber  38  to the supply chamber  40  when the piston  24  is in the first position, and blocks the flow when the piston  24  is in the second position. The return valve  28  is fixed to the piston  24 , blocks the coating material  18  from flowing from the inflow chamber  38  to the return chamber  42  when the piston  24  is in the first position, and allows the flow when the piston  24  is in the second position. The valve diameter D 1  of the supply valve  26  is set to 1.53 times or more the valve diameter D 2  of the return valve  28 . 
     By setting the valve diameter D 1  of the supply valve  26  to be 1.53 times or more the valve diameter D 2  of the return valve  28 , the suck back amount of the coating material  18  when the piston  24  is displaced from the first position to the second position can be increased so as to suppress the scattering of the coating material  18  on the uncoated part  16   a . Thereby, the accuracy of applying the coating material  18  can be improved without complicating the structure of the intermittent valve  4  and even the intermittent coating apparatus  1 . Further, the intermittent coating can be speeded up while maintaining the accuracy of applying the coating material  18 . Therefore, according to the present embodiment, it is possible to achieve both shortening of the manufacturing time and maintenance of quality of the electrode plates. 
     Further, the supply valve  26  according to the present embodiment has a first flat part  26   a  extending in a direction orthogonal to the axial direction X of the piston  24  on a surface facing the first downstream end  38   b  side. Further, the valve main unit  22  has a second flat part  22   a  that comes into surface contact with the first flat part  26   a  when the piston  24  is in the second position. The supply valve  26  having the first flat part  26   a  allows the suck back amount to be increased more reliably. Therefore, the accuracy of applying the coating material  18  can be further improved. Further, the first flat part  26   a  and the second flat part  22   a  can suppress the leakage of the coating material  18  from the inflow chamber  38  to the supply chamber  40 . Therefore, the accuracy of applying the coating material  18  can be further improved. 
     Further, the first flat part  26   a  and the second flat part  22   a  can suppress an instantaneous increase in the flow rate of the coating material  18  when the supply valve  26  is opened. Thereby, a sudden increase in the amount of the coating material  18  discharged from the die  2  can be suppressed when the intermittent valve  4  switches from the second state to the first state. Therefore, it is possible to suppress the coating thickness of the coated part  18   a  from increasing in a boundary region with the uncoated part  16   a  and make the coating thickness of the coated part  18   a  uniform. 
     When the coating thickness of the coated part  18   a  is made uniform, the entire coated part  18   a  can be pressed more reliably in press working after the coating step of the coating material  18 . Thereby, the density of the entire coated part  18   a  can be increased, and the entire coated part  18   a  can be brought into close contact with the coating target  16 . As a result, it is possible to suppress the battery performance of a part of the coated part  18   a  from deteriorating or being peeled off from the coating target  16 . Further, the first flat part  26   a  receiving the hydraulic pressure of the coating material  18  that flows out from the inflow chamber  38  to the supply chamber  40  allows the supply valve  26  to follow the displacement of the piston  24  with higher accuracy. Thereby, the supply and non-supply of the coating material  18  to the die  2  can be switched with higher accuracy, and the accuracy of applying the coating material  18  can be further improved. 
     The intermittent coating apparatus  1  includes: a tank  6  that stores a coating material  18 ; a feed line  10  and a return line  12  that connect the tank  6  and an intermittent valve  4 ; and a pump  8  that is provided in the feed line  10  and that sends the coating material  18  to the intermittent valve  4  from the tank  6 . The coating material  18  returns to the tank  6  via the return line  12  when the intermittent valve  4  is in the second state. Thereby, the supply of the coating material  18  to the intermittent valve  4  can be continued even when the discharge of the coating material  18  from the die  2  is stopped. Therefore, since the pump  8  can be constantly driven, the system configuration of the intermittent coating apparatus  1  can be simplified. 
     Described above is a detailed explanation of the embodiments of the present invention. The above-described embodiments merely show specific examples for carrying out the present invention. The details of the embodiments do not limit the technical scope of the present invention, and many design modifications such as change, addition, deletion, etc., of the constituent elements may be made without departing from the spirit of the invention defined in the claims. New embodiments resulting from added design change will provide the advantages of the embodiments and variations that are combined. In the above-described embodiments, the details for which such design change is possible are emphasized with the notations “according to the embodiment”, “in the embodiment”, etc. However, design change is also allowed for those without such notations. Optional combinations of the above components are also valid as embodiments of the present invention. Hatching applied to a cross section of a drawing does not limit the material of an object to which the hatching is applied. 
     In the embodiments, the height position of the second opening  32  and the height position of the fourth opening  36  are aligned, and the supply chamber  40  is bent in the course from the first connecting part  44  to the fourth opening  36 . However, the fourth opening  36  may be located below the second opening  32 , and the supply chamber  40  may extend linearly in the horizontal direction from the first connecting part  44 .