JP7119976B2 - Fuel cell separator manufacturing equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to an apparatus for manufacturing fuel cell separators.

A fuel cell has a fuel cell stack in which a plurality of unit cells are stacked. Each unit cell has a membrane electrode assembly or a membrane electrode gas diffusion layer assembly and two separators sandwiching the membrane electrode assembly or the membrane electrode gas diffusion layer assembly. One surface of the separator is formed with a reaction gas flow path for flowing a reaction gas inside the unit cell, and the other surface is formed with a cooling medium flow path for flowing a cooling medium inside the unit cell. .

Fuel cell separators are required to have high conductivity and corrosion resistance. For this reason, a separator material made of metal as a base material is generally coated with carbon black on its surface and then baked by heat treatment. As a material for the separator material, a metal plate material such as SUS (iron, chromium, nickel), titanium, or the like is used.

By the baking treatment, a mixed layer containing the separator material and carbon black is formed on the surface of the separator material. This mixed layer has sufficient electrical conductivity. Generally, some carbon black remains as surplus carbon on the mixed layer, and a process for removing this surplus carbon is performed. Patent Document 1 describes that the removal of this surplus carbon is performed by a so-called water jet method in which water is jetted onto the surface of the separator material after the baking 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 have experienced that excess carbon remains unremoved when jet treatment is not performed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a method for reliably removing surplus carbon remaining on the surface of a fuel cell separator formed by firing carbon black on the surface of a metal material. An object of the present invention is to provide an apparatus for manufacturing a fuel cell separator capable of

An apparatus for manufacturing a fuel cell separator according to the present invention comprises a baking unit for baking a metallic separator material having a surface coated with carbon black, and a baking unit for removing surplus carbon present on the surface of the separator material after baking. and an ultrasonic cleaning unit, wherein the ultrasonic cleaning unit guides a cleaning tank, an ultrasonic vibrator disposed on the bottom surface of the cleaning tank, and the separator material after baking that is conveyed in the cleaning tank. guide rollers, the guide rollers being a first guide roller group for guiding the conveyed separator material after sintering in a horizontal direction along the oscillation surface of the ultrasonic transducer; a second guide roller group higher than the first guide roller group on the rear side of the transportation of the baked separator material sent out from the roller group, and at least one of the second guide roller group A rotating brush is arranged on the second guide roller so as to come into contact with the fired separator material guided on the second guide roller.

In the fuel cell separator manufacturing apparatus according to the present invention, the excess carbon remaining on the surface of the separator material after baking can be reliably removed by ultrasonic cleaning. In addition, it is possible to prevent the excess carbon after peeling from adhering to the surface of the separator material again. As a result, it is possible to reliably manufacture a fuel cell separator as desired without surplus carbon on the surface.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view for explaining a main part of an apparatus for manufacturing a fuel cell separator according to an embodiment; FIG. 4 is a diagram for explaining a state in which excess carbon existing on the surface of the separator material after firing is removed by ultrasonic cleaning.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram for explaining a main part of a fuel cell separator manufacturing apparatus 100 according to an embodiment.

A fuel cell separator manufacturing apparatus 100 includes a carbon black applying section 20 for applying carbon black to the front and back surfaces of a metal separator material as a base material 10, and is positioned downstream of the base material 10 in the feeding direction. A baking unit 30 is 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 ones, and detailed description thereof will be omitted. Examples of the metal separator material as the base material 10 include thin SUS (iron, chromium, nickel) and titanium.

In the fuel cell separator manufacturing apparatus 100, a long metal material wound into a roll is used as the base material 10, and the base material 10 unwound from the roll 11 has a carbon black coating portion 20. In the process of passing, both sides are coated with carbon black. The base material 10 a coated with carbon black is sent into the baking section 30 . The substrate 10a coated with carbon black is subjected to heat treatment in the baking unit 30, and the carbon black is baked. The baked base material 10 b is then sent to the ultrasonic cleaning section 40 .

By undergoing heat treatment in the baking unit 30, a mixed layer containing the metal material as the base material and carbon black is formed on the surface of the base material 10. FIG. A portion of the carbon black usually remains as surplus carbon on the mixed layer. This remaining surplus carbon is an unnecessary material for the fuel cell separator and must be removed. The ultrasonic cleaning unit 40 removes the surplus carbon 25 .

The ultrasonic cleaning unit 40 includes a box-shaped cleaning tank 41 with an open top. The inside of the cleaning tank 41 is filled with a cleaning liquid. The baked base material 10 b sent out from the baking section 30 passes through the washing tank 41 while being guided by guide rollers. Specifically, the base material 10b after baking, which leaves the baking section 30 and moves in the X-axis direction, is guided by the first external guide rollers 42 positioned above the cleaning tank 41 (+side in the Z-axis direction) and outside the tank. It is guided downward in the vertical direction (Z-axis direction) and enters the cleaning tank 41 . The base material 10b after sintering that has entered the cleaning tank 41 is guided in the cleaning tank 41 by the first lower guide roller 43 having an axial center in the Y-axis direction, and oriented in the horizontal direction (X-axis direction). change.

The fired base material 10b that has changed its orientation in the horizontal direction moves in the cleaning tank 41 in the X-axis direction. Then, it moves to the second lower guide roller 44 having an axis parallel to the first lower guide roller 43, where it turns upward (Z-axis direction + side) and moves vertically upward. The first lower guide roller 43 and the second lower guide roller 44 correspond to an example of the "first guide roller" in the present invention.

An upper guide roller 45 having an axis parallel to the first inner guide roller 43 is positioned in the cleaning tank 41 . The upper guide roller 45 is located above the first lower guide roller 43 and the second lower guide roller 44 (Z-axis direction + side). The upper guide rollers 45 correspond to an example of "a second guide roller group higher than the first guide roller group" in the present invention.

A brush roller 50 having the same length as the Y-axis direction of the upper guide roller 45 is positioned above the upper guide roller 45 (on the positive side in the Z-axis direction) with its axial centers parallel to each other. The brush roller 50 is positioned above the upper guide roller 45 so that the tip of the brush contacts the peripheral surface of the upper guide roller 45 . A rotational force is transmitted to the brush roller 50 from a driving source (not shown). The brush roller 50 corresponds to an example of the "rotating brush" according to the invention.

Guided by the second lower guide roller 44, the base material 10b after baking changes its direction upward (+ side in the Z-axis direction) and moves vertically upward. pass. After passing, the fired substrate 10b, turned vertically downward, passes a third lower guide roller 46 whose Z-axis position is substantially the same as the second lower guide roller 44, where It turns around and is guided vertically upwards. After that, the baked base material 10b moves out of the washing tank 41, passes through a second external guide roller 47 having an axis parallel to that of the first external guide roller 42, and is taken up by a roller (not shown). be done. It is also sent to the cutting processing section and the forming processing section.

In the fuel cell separator manufacturing apparatus 100, the back surface side ( The ultrasonic transducer 60 is positioned on the Z-axis direction (− side). The ultrasonic transducer 60 has a flat oscillation surface in the X-axis direction, and is directed toward the back side of the baked base material 10b moving from the first lower guide roller 43 toward the second lower guide roller 44. , that is, upward (Z-axis direction + side). Note that 61 is an ultrasonic oscillator.

FIG. 2 illustrates a state in which excess carbon 25 existing on the surface is removed by irradiating the fired base material 10b with ultrasonic waves from the ultrasonic transducer 60. FIG. In FIG. 2, only the surplus carbon 25 existing on the surface of the base material 10b after firing is illustrated for the sake of clarity.

FIG. 2(a) shows the state before the ultrasonic wave is applied, and the baked base material 10b is positioned parallel to the oscillation surface of the ultrasonic transducer 60. FIG. FIG. 2(b) schematically shows a state when ultrasonic waves are applied. The oscillated ultrasonic waves are applied to the rear surface of the fired base material 10b. As a result, cavitation occurs on the back surface of the base material 10b after baking, and the surplus carbon 25 on the back surface side is removed. The surplus carbon 25 after removal falls downward by its own weight. Some of the ultrasonic waves pass through the base material 10b after baking and reach the upper surface side of the base material 10b after baking. As a result, cavitation occurs also on the upper surface side of the base material 10b after baking, and the surplus carbon 25 on the upper surface side is also removed. The removed surplus carbon 25 temporarily floats on the upper surface side of the fired base material 10b, but with time, it falls on the upper surface side of the fired base material 10b, as shown in FIG. 2(c). In addition, there is a risk of re-adherence to the upper surface side of the base material 10b after firing.

In the fuel cell separator manufacturing apparatus 100 of the embodiment, this reattachment can be effectively prevented. As shown in FIG. 1, in the fuel cell separator manufacturing apparatus 100, when the fired substrate 10b is moving from the first lower guide roller 43 to the second lower guide roller 44, the The base material 10b is irradiated with ultrasonic waves from the ultrasonic transducer 60, as shown in FIG. 2(b). As a result, excess carbon present on both sides is peeled off and removed. However, on the upper surface side (Z-axis direction + side) of the base material 10b after firing, as shown in FIG.

In the fuel cell separator manufacturing apparatus 100, even if the excess carbon re-adheres, the brush roller 50 will not move when the fired base material 10 passes between the upper guide roller 45 and the brush roller 50. , the redeposited surplus carbon is again removed from the surface of the base material 10 after baking. Therefore, unnecessary surplus carbon does not remain on the surface of the base material 10b after firing sent out from the ultrasonic cleaning unit 40, and a desired fuel cell separator can be obtained. In the fuel cell separator manufacturing apparatus 100 described above, one pair of the upper guide roller 45 and the brush roller 50 is provided, but two or more pairs may be provided.

100... Apparatus for manufacturing fuel cell separators,
10 ... base material (metal separator material),
10a ... base material coated with carbon black,
10b ... Base material after carbon black firing treatment,
11 ... Roll of base material,
20... carbon black coated portion,
25 ... surplus carbon,
30... Firing section,
40... Ultrasonic cleaning section,
41... Washing tank,
42 ... the first external guide roller,
43... First lower guide roller,
44 ... second lower guide roller,
45... upper guide roller,
46 ... third lower guide roller,
47 ... second external guide roller,
50... brush roller,
60... Ultrasonic vibrator,
61... Ultrasonic oscillator.

Claims (1)

An apparatus for manufacturing a fuel cell separator,
a baking unit that bakes a metallic separator material with carbon black applied to the surface;
an ultrasonic cleaning unit for removing excess carbon present on the surface of the separator material after baking,
The ultrasonic cleaning unit includes a cleaning tank, an ultrasonic oscillator arranged on the bottom surface of the cleaning tank, and a guide roller for guiding the baked separator material conveyed in the cleaning tank,
The guide rollers include a first guide roller group that guides the conveyed separator material after sintering in the horizontal direction along the oscillation surface of the ultrasonic transducer; and a second guide roller group higher than the first guide roller group on the rear side of the separator material after baking, and at least one second guide roller of the second guide roller group A rotating brush is arranged so as to be in contact with the fired separator material guided on the second guide roller,
A fuel cell separator manufacturing apparatus characterized by:

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