JP7306969B2 - Fuel cell separator manufacturing equipment - Google Patents

Description

The present disclosure relates to an apparatus for manufacturing fuel cell separators.

Generally, a fuel cell has a fuel cell stack in which a plurality of single cells are stacked. Each single cell has a membrane electrode assembly and two fuel cell separators sandwiching the membrane electrode assembly. Fuel cell separators are required to have high electrical conductivity and corrosion resistance. For this reason, a metal material for a fuel cell separator is sometimes subjected to a sintering treatment by heat treatment after the carbon black is applied to the surface of the metal material. By the baking treatment, a mixed layer containing the metal material and carbon black is formed on the surface of the metal material. Since some carbon black may remain as surplus carbon on the surface of this mixed layer, a treatment for removing this surplus carbon may be performed. Patent Document 1 describes that the removal of the excess carbon is performed by a so-called water jet method in which water is jetted onto the surface of the metal material after the firing treatment.

JP 2017-191640 A

In the production of fuel cell separators, the present inventors have often carried out excess carbon removal treatment by the water jet method as described in Patent Document 1. We experienced that excess carbon was left behind if no treatment was performed.

The present disclosure has been made in view of the above circumstances, and an object of the present disclosure is to provide a fuel cell separator manufacturing apparatus capable of removing excess carbon by suppressing the excess carbon remaining on the surface of the metal material. do.

The present disclosure can be implemented as the following forms.

According to one aspect of the present disclosure, an apparatus for manufacturing a fuel cell separator is provided. This fuel cell separator manufacturing apparatus includes a cleaning tank capable of storing a liquid, and a plate-shaped metal material for the fuel cell separator obtained by baking after coating carbon black on the surface. a conveying unit that conveys the liquid in the cleaning tank while facing the direction; and an ultrasonic irradiation unit that applies ultrasonic waves from below to the metal material being conveyed in the cleaning tank. and a liquid injection nozzle for generating a flow of the liquid in a direction crossing the conveying direction at least on the lower side of the metal material conveyed in the cleaning tank, which is the upper side and the lower side. .

According to the fuel cell separator manufacturing apparatus of this aspect, the liquid is caused to flow in a direction crossing the conveying direction at least toward the lower side of the metallic material conveyed in the cleaning tank. Since the liquid injection nozzle is provided, the metal material conveyed in the cleaning tank is prevented from sagging due to its own weight. It is possible to maintain a high carbon black removal force. Therefore, the excess carbon can be removed while suppressing the excess carbon black remaining on the surface.

1 is an overview schematic diagram of a manufacturing apparatus for a fuel cell separator as an embodiment of the present disclosure; FIG. 1 is a partial schematic plan view of a fuel cell separator manufacturing apparatus; FIG. 1 is a partial schematic side view of a fuel cell separator manufacturing apparatus; FIG. FIG. 4 is a schematic diagram showing how cleaning is performed by an ultrasonic oscillator and a liquid jet nozzle;

A. First embodiment:
FIG. 1 is an overview schematic diagram of a fuel cell separator manufacturing apparatus 100 as an embodiment of the present disclosure. In FIG. 1, an X-axis, a Y-axis and a Z-axis that are orthogonal to each other are shown. In this embodiment, the -Z direction corresponds to vertically downward. The X-axis direction and the Y-axis direction are parallel to the horizontal direction. "X-axis direction" means a concept combining the +X direction and the -X direction. Similarly, the "Y-axis direction" means a concept combining the +Y direction and the -Y direction, and the "Z-axis direction" means a concept combining the +Z direction and the -Z direction. The X-axis, Y-axis and Z-axis in other drawings described later correspond to the X-axis, Y-axis and Z-axis in FIG.

A fuel cell separator manufacturing apparatus 100 includes a carbon black coating unit 20 for coating carbon black on the front and back surfaces of a metal material 10 as a base material of a fuel cell separator, and a downstream side of the metal material 10 in the conveying direction. A baking unit 30 , a conveying unit 40 , a cleaning tank 50 , a plurality of ultrasonic transducers 60 , and a plurality of liquid injection nozzles 70 are provided.

The firing section 30 includes a heating section for heat treatment. The carbon black coating section 20 and the baking section 30 may be conventionally known, and detailed description thereof will be omitted. Examples of the metal material 10 include thin SUS (iron, chromium, nickel) and thin plate materials made of metal such as titanium.

In the fuel cell separator manufacturing apparatus 100, the metal material 10 is prepared as a long thin plate metal material wound into a roll. The belt-shaped metal material 10 unwound from the roll 11 so that the surface of the plate-shaped metal material 10 for the fuel cell separator faces the vertical direction, passes through the carbon black coating section 20, and carbon black is applied to both sides of the metal material 10. Black is applied. The metal material 10 a coated with carbon black is sent into the baking section 30 . The metal material 10a coated with carbon black is subjected to heat treatment in the baking unit 30, and the carbon black is baked. The metal material 10b obtained by sintering is supported in a belt shape and sent to the transport section 40 .

A mixed layer containing the metal material forming the metal material 10 and carbon black is formed on the surface of the metal material 10 by undergoing heat treatment in the firing section 30 . A portion of the carbon black usually remains as surplus carbon on the surface of the mixed layer. This remaining surplus carbon is an unnecessary material for the fuel cell separator, and is preferably removed.

The conveying section 40 includes a first outer guide roller 42 , a first lower guide roller 43 , a second lower guide roller 46 and a second outer guide roller 47 . The conveying unit 40 conveys the metal material 10b so as to pass through a cleaning tank 50, which is described later, for removing surplus carbon. Specifically, the conveying unit 40 conveys the metal material 10b in the cleaning tank 50 in which the liquid (cleaning liquid) is stored with the surface of the metal material 10b facing the vertical direction.

The sintered metal material 10b conveyed from the sintering unit 30 is fed by a first outer guide roller 42, a first lower guide roller 43, a second lower guide roller 46, and a second outer guide roller 47. , and passes through the cleaning tank 50 . Specifically, the fired metal material 10b moving in the +X direction out of the firing section 30 is guided by the first external guide rollers 42 located outside the cleaning bath 50 in the +Z direction, and vertically It turns in the −Z direction, which is the downward direction, and enters the cleaning liquid in the cleaning bath 50 . The sintered metal material 10b that has entered the cleaning liquid is guided in the cleaning tank 50 by the first lower guide roller 43 having an axis in the Y-axis direction, and changes its orientation in the horizontal direction (X-axis direction).

The sintered metal material 10b that has changed its orientation in the horizontal direction moves in the cleaning tank 50 in the +X direction, which is the transport direction. Then, it moves to the second lower guide roller 46 having an axis parallel to the first lower guide roller 43, where it turns upward in the +Z direction and moves vertically upward. After that, the fired metal material 10b moves out of the cleaning tank 50, passes through a second external guide roller 47 having an axis parallel to that of the first external guide roller 42, and is wound up on a roller (not shown). be done. Alternatively, it is sent to a drying processing section, a cutting processing section, or a forming processing section.

The cleaning tank 50 is a box-shaped cleaning tank with an open top, and is capable of storing a liquid (cleaning liquid). In this embodiment, the cleaning tank 50 stores water as the cleaning liquid. The cleaning liquid is not limited to water, and may be an alkaline cleaning liquid, ethanol, a hydrocarbon cleaning liquid, nitric acid, or the like.

The plurality of ultrasonic transducers 60 are all positioned on the inner bottom surface of the cleaning tank 50 . A plurality of ultrasonic transducers 60 are arranged along the X-axis direction. The ultrasonic transducer 60 has a flat oscillation surface parallel to the XY plane. The ultrasonic oscillator 60 irradiates the metal material 10b conveyed in the cleaning tank 50 with ultrasonic waves from below in the +Z direction. The ultrasonic transducer 60 removes excess carbon remaining on the surface of the metal material 10b by irradiating sound waves. A plurality of ultrasonic transducers 60 are all connected to a common ultrasonic oscillator 61 . In this embodiment, the ultrasonic intensity of the ultrasonic oscillator 61 is constant. As implementation conditions, the frequency of ultrasonic waves is 78 kHz, the irradiation amount is 1000 to 1200 W, and the sound pressure is 0.2 to 0.3 MPa. Note that the frequency of the ultrasonic waves, the irradiation amount, and the sound pressure may be other arbitrary numerical values.

The plurality of liquid injection nozzles 70 are positioned on the inner side surface of the cleaning tank 50, that is, at the end of the cleaning tank 50 in the Y-axis direction. As shown in FIG. 1, the heights (positions in the Z-axis direction) of the arrangement positions of the plurality of liquid injection nozzles 70 are all the metal It is approximately the same height as the material 10b. A plurality of liquid injection nozzles 70 are alternately arranged along the conveying direction of the metal material 10b at the +Y direction end and the −Y direction end of the cleaning tank 50 . The liquid injection nozzle 70 forms a +Y direction water flow or a −Y direction water flow in the cleaning tank 50 . Specifically, as shown in FIG. 4, which will be described later, the liquid is caused to flow in a direction crossing the transport direction with respect to the upper side and the lower side of the metal material 10b transported in the cleaning tank 50. As shown in FIG. In this embodiment, the "intersecting direction" is the orthogonal direction. The liquid injection nozzle 70 suppresses the metal material 10b conveyed in the cleaning tank 50 from sagging due to its own weight, and the position of the metal material 10b in the depth direction in the cleaning tank 50 is radiated from the ultrasonic oscillator 60. It plays a role in maintaining a high carbon black removal force by sound waves. It should be noted that although water is jetted from the liquid jet nozzle 70 in this embodiment, other liquids may be used instead of water.

FIG. 2 is a partial schematic plan view of the manufacturing apparatus 100 for fuel cell separators. FIG. 3 is a partial schematic side view of the manufacturing apparatus 100 for fuel cell separators. As shown in FIGS. 2 and 3, a plurality of ultrasonic transducers 60 are arranged at equal intervals in the X-axis direction on the bottom surface of a cleaning tank 50 in which water is stored. A belt-shaped metal material 10 b is positioned above the ultrasonic transducer 60 in the +Z direction. The speed at which the metal material 10b passes is 3 m/min in this embodiment. Note that the speed is not limited to 3 m/min and may be any speed. In this embodiment, the distance in the Z-axis direction from the liquid surface 50a to the ultrasonic transducer 60 is 75 mm. Note that the distance is not limited to 75 mm and may be any distance. Also, in the present embodiment, the plurality of ultrasonic transducers 60 are arranged at equal intervals in the X-axis direction on the bottom surface of the cleaning tank 50, but the arrangement may not be at equal intervals. In addition, the ultrasonic transducer 60 corresponds to the ultrasonic irradiation unit in the claims.

As shown in FIG. 2, the plurality of liquid injection nozzles 70 are positioned on the inner side surface of the cleaning tank 50 in the -Y direction and then on the inner side surface of the cleaning tank 50 in the +Y direction in order along the X-axis direction. They are arranged alternately on the side surface of the cleaning tank 50 so as to do so. The ejection from the alternately arranged liquid ejection nozzles 70 suppresses meandering of the metal material 10b in the Y-axis direction. The injection intensity of the liquid injection nozzle 70 is constant. In this embodiment, the liquid injection nozzle 70 is a 1/4M EJX S70×2-4 S303 manufactured by Kirino Ikeuchi. Note that other types of nozzles may be used.

FIG. 4 is a schematic diagram showing how cleaning is performed by the ultrasonic oscillator 60 and the liquid jet nozzle 70. As shown in FIG. The liquid injection nozzle 70 is positioned on the inner side surface of the cleaning tank 50 in the -Y direction, and the ultrasonic vibrator 60 is positioned on the inner bottom surface of the cleaning tank 50 . The ultrasonic transducer 60 irradiates ultrasonic waves in the +Z direction from the +Z direction end face. 4 shows only the liquid injection nozzles 70 arranged on the inner side surface in the −Y direction of the cleaning tank 50, and the liquid injection nozzles 70 arranged on the inner side surface in the +Y direction are omitted. The liquid injection nozzle 70 is arranged so that the position in the Z-axis direction is substantially the same as the position in the Z-axis direction of the metal material 10b to be transported, and is centered on the +Y direction and extends from the -Z direction to the +Z direction. sprays water over a wide angle. Although not shown, the liquid jet nozzle 70 jets water so as to spread slightly in the X-axis direction as well. For this reason, the liquid injection nozzle 70 sprays water in approximately the +Y direction to both the upper side (+Z direction side) and the lower side (−Z direction side) of the metal material 10b conveyed in the cleaning tank 50. produce flow.

When ultrasonic waves are emitted from the ultrasonic oscillator 60 , a standing wave w<b>1 of sound pressure is generated in the water in the cleaning tank 50 . This standing wave w1 has a node at the liquid surface 50a, and λ/4+(λ/2)×n (λ is one wavelength. n is an integer equal to or greater than 0) in the −Z direction from the liquid surface 50a. These waves have antinodes 50b, 50c, and 50d for each distance. Antinodes 50b, 50c, and 50d of the standing wave w1 have a higher sound pressure than other portions and a greater ability to remove excess carbon.

As shown in FIG. 4, in this embodiment, the metal material 10b is arranged so that the position in the Z-axis direction coincides with the position in the Z-axis direction of the antinode 50c of the standing wave w1, and maintains that position. transported in this way. Such positional maintenance is realized by water jets jetted from a plurality of liquid jet nozzles 70 in addition to the first lower guide roller 43 and the second lower guide roller 46 . A detailed description will be given below.

The positions of the ends in the -Z direction of the outer peripheral surfaces of the two lower guide rollers 43 and 46 are set substantially equal to the position of the belly 50c in the Z-axis direction. Therefore, by being let out by the two lower guide rollers 43, 46, the position of the metal material 10b in the Z-axis direction near these lower guide rollers 43, 46 is substantially equal to the position of the belly 50c in the Z-axis direction. Become. Here, when the metal material 10b is conveyed in the cleaning tank 50 by the rotation of the first lower guide roller 43 and the second lower guide roller 46, water is jetted from any of the liquid jet nozzles 70. If not, the metal material 10b will hang down in the -Z direction in a catenary shape (catendron shape) centering on the center position in the X-axis direction between the two lower guide rollers 43 and 46 due to its own weight. However, between the two lower guide rollers 43 and 46, by jetting water from each liquid jetting nozzle 70, the metal material 10b to be conveyed is substantially Y-axis Directional water flow is formed. Therefore, the flow of water suppresses the position of the conveyed metal material 10b from shifting in the Z-axis direction, thereby suppressing the hanging of the metal material 10b. As a result, the metal material 10b is conveyed while its Z-axis position is maintained at the Z-axis position of the bulge 50c.

According to the fuel cell separator manufacturing apparatus 100 of the embodiment described above, the liquid flows in the direction crossing the conveying direction with respect to the upper side and the lower side of the metal material 10b conveyed in the cleaning tank 50. Since the liquid injection nozzle 70 is provided, the metal material 10b conveyed in the cleaning tank 50 is prevented from sagging due to its own weight. The force of removing carbon black by sound waves emitted from the surface can be maintained at a high position, and surplus carbon black remaining on the surface can be suppressed and removed.

B. Other embodiments:
(B1) In the fuel cell separator manufacturing apparatus 100 of the above embodiment, the liquid injection nozzle 70 is arranged so that the position (height) in the Z-axis direction is substantially the same as the position in the Z-axis direction of the metal material 10b to be conveyed. , but the present disclosure is not limited thereto. For example, the liquid injection nozzle 70 has two upper and lower nozzles. One nozzle injects the cleaning liquid in the +Y direction toward the upper side of the metal material 10b, and the other nozzle is below the metal material 10b. The position in the Z-axis direction of the arrangement position (the center of gravity position) of the entire liquid injection nozzle 70 having these two nozzles is the Z-axis of the conveyed metal material 10b. A configuration different from the position of the direction may be used. Also, in the present embodiment, the direction of the flow of the cleaning liquid above and below the metal material 10b is substantially the Y-axis direction, but the present disclosure is not limited to this. Any direction intersecting with the X-axis direction and the Z-axis direction may be used. That is, in general, a nozzle that generates a flow of cleaning liquid in a direction that intersects the conveying direction is applied to both the upper side and the lower side of the metal material 10b that is conveyed in the cleaning tank 50. It may be a nozzle.

(B2) In the fuel cell separator manufacturing apparatus 100 of the first embodiment, the liquid injection nozzles 70 are alternately arranged in the conveying direction on the inner side surface of the cleaning tank 50 in the −Y direction and the inner side surface in the +Y direction. It does not have to be placement. The liquid injection nozzle 70 may be positioned only on the inner side surface in the -Y direction or may be positioned only on the inner side surface in the +Y direction.

(B3) In the fuel cell separator manufacturing apparatus 100 of the first embodiment, the liquid injection nozzle 70 directs the flow of water to both the upper side and the lower side of the metal material 10b conveyed in the cleaning tank 50. However, the present disclosure is not limited to this. The liquid injection nozzle 70 may generate a flow of water in a direction crossing the conveying direction only on the lower side of the metal material 10b. Also in such a configuration, it is possible to suppress sagging due to its own weight.

(B4) In the fuel cell separator manufacturing apparatus 100 of the first embodiment, the position in the Z-axis direction of the metal material 10b is arranged to be substantially equal to the position in the Z-axis direction of the antinode 50c of the standing wave w1. However, the present disclosure is not limited to this. The position of the metal material 10b in the Z-axis direction does not have to be substantially equal to the position of the antinode in the Z-axis direction unless it is the position of the node of the standing wave w1 in the Z-axis direction.

(B5) In the fuel cell separator manufacturing apparatus 100 of the first embodiment, the ultrasonic transducer 60 is arranged on the inner bottom surface of the cleaning tank 50, but the present disclosure is not limited to this. The ultrasonic transducer 60 may be arranged on the outer bottom surface of the cleaning tank 50 .

The present disclosure is not limited to the embodiments described above, and can be implemented in various configurations without departing from the scope of the present disclosure. For example, the technical features of the embodiments corresponding to the technical features in each form described in the outline of the invention are used to solve some or all of the above problems, or Alternatively, replacements and combinations can be made as appropriate to achieve all. Also, if the technical features are not described as essential in this specification, they can be deleted as appropriate.

w1...Standing wave 10...Metal material 10a...Metal material 10b...Metal material 11...Roll 20...Carbon black coating part 30...Baking part 40...Conveying part 42...First external guide roller , 43... First lower guide roller, 46... Second lower guide roller, 47... Second outer guide roller, 50... Washing tank, 50a... Liquid surface, 50b... Convex, 50c... Concern, 50d... Concern, 60... Ultrasonic vibrator, 61... Ultrasonic oscillator, 70... Liquid injection nozzle, 100... Manufacturing apparatus

Claims (1)

An apparatus for manufacturing a fuel cell separator,
a cleaning tank capable of storing liquid;
The plate-shaped metal material for the fuel cell separator obtained by firing after applying carbon black on the surface is conveyed in the cleaning tank in which the liquid is stored with the surface facing the vertical direction. a conveying unit that
an ultrasonic irradiating unit that irradiates ultrasonic waves from below onto the metal material conveyed in the cleaning tank;
a liquid injection nozzle that causes the liquid to flow in a direction that intersects with the conveying direction toward at least one of the upper side and the lower side of the metal material conveyed in the cleaning tank;
An apparatus for manufacturing a fuel cell separator, comprising:

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