JP2001038624A - Flat work machining method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form fine grooves in a flat work with high accuracy while minimizing the fraction defective in the machining. SOLUTION: In this working method, the masking of a part other than the part to form bottomed grooves 4, 7 of a work (substrate) 1 is implemented in advance by covering the part with a masking material 13. A flat soft backing member 16 is stuck on a base plate 14 and fixed thereto by a lower adhesive 15a, and the masked work 1 is stuck on the soft backing member 16 and fixed thereto by an upper adhesive 15b. The fixed work 1 is mounted on a sand blasting machine together with the base plate 14, and the blasting is executed to form the bottomed grooves 4, 7 in a part to be machined without any masking material 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of processing a flat work such as a jig used for assembling a substrate and a semiconductor in a fuel cell separator used by being mounted on a portable power supply or an electric vehicle. Things.

[0002]

2. Description of the Related Art A fuel cell separator is composed of a thin plate-shaped substrate made of metal or carbon. A fluid passage for supplying a fuel gas such as hydrogen or an oxidizing gas such as oxygen is provided on the surface of the substrate. Numerous fine bottomed grooves forming a cooling water passage for supplying the cooling water are formed. Conventionally, the bottomed groove of the above-mentioned substrate is provided by mounting the substrate, which is a work, directly on a rigid support plate such as a jig or a pallet and mounting the same on a processing machine, and performing high-energy processing such as machining such as cutting or electric discharge machining. Was formed by

[0003]

However, the conventional method of processing a groove with a bottom in the above-mentioned conventional method has a problem in that the material is easily chipped at the time of the groove processing, especially when the substrate is made of a brittle material, so that an accurate groove is formed. In some cases, the shape cannot be obtained, or the substrate is damaged and cannot be used as a product.Therefore, there is a problem that the yield in processing is poor, and in the latter case, the processing efficiency is poor regardless of the processing accuracy. There is dissatisfaction that production cost increases.

The present invention provides a method of processing a flat work, which can form a fine groove with a bottom with high precision without damaging the work even on a brittle flat work. The purpose is to provide. It is another object of the present invention to provide a method of processing a flat work, which can reduce the defective rate in processing and can process the work at low cost.

[0005]

In order to achieve the above object, according to the first aspect of the present invention, a flat work in which a non-processed portion is covered with a mask material is provided by interposing a soft backing member on a base plate. , And a bottomed groove is formed by sandblasting in a required processed portion of the work. In the method having the above configuration, when processing the bottomed groove by sandblasting, the impact of the injection pressure of the beads on the work is moderately buffered by the soft backing member. In addition, the beads are prevented from being broken, and scattering of beads rebounding due to the formation of the groove on the groove wall is suppressed, so that the bottomed groove is accurately formed.

In the method according to the first aspect, when the soft backing material is made of a polyurethane resin (claim 2), the effect of cushioning the impact due to the injection pressure of the beads is optimized, and the formation of the groove is further improved. Done in The method according to claim 1 or 2, wherein the work is fixed to the base plate with an adhesive adhered to both surfaces of the soft backing material (claim 3). In addition, the workpiece is easily fixed to the base plate and can be easily handled with a sand blasting machine or the like, and the groove is processed with high precision.

In the method according to any one of claims 1 to 3, the bottomed groove may have a cross-sectional shape in which the groove width on the opening side and the groove width on the bottom side are different. Item 4), even in this case, machining of the groove is performed smoothly. In the method according to the fourth aspect, it is possible to configure the cross section in which the groove width on the opening side is small and the groove width on the bottom side is large is trapezoidal. In this configuration, even if the edges of the groove on the opening side and the grooves on both sides on the bottom side are acute angles, the groove can be accurately and easily processed without any damage.

In a method according to claim 4 or 5, after forming a temporary groove having a rectangular cross section having a width equal to the smaller dimension of the groove width, a bottomed portion is formed on the side of the temporary groove. When the widening groove for completing the cross-sectional shape of the groove is formed (claim 6), the groove can be processed more smoothly and easily. In the method according to any one of claims 1 to 6, the work may be a substrate of a fuel cell separator (claim 7). In the method according to any one of the aspects, the work may be made of carbon. In these configurations, the groove processing for the thin brittle work is performed safely and easily without causing damage to the work.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to processing of a fuel cell separator substrate will be described below with reference to the accompanying drawings. 1 and 2, reference numeral 1 denotes a substrate of a fuel cell separator. The substrate 1 is composed of a carbon plate impregnated with a thermosetting resin such as a phenol resin or an epoxy resin and an amorphous carbon plate, and is formed in a substantially rectangular shape with a thin flat plate. A fluid passage 2 for supplying a fuel gas such as hydrogen or an oxidizing gas such as oxygen is provided on one surface 1a of the substrate 1, and a cooling water is supplied on the other surface (opposite surface) 1b. A cooling water passage 3 is provided.

The fluid passage 2 has a large number of parallel bottomed grooves 4 formed in a straight line in the vertical direction in FIG. 1, and the upstream side is connected to a gas inlet hole 6 for fuel gas through an inlet groove 5a. , The downstream side is connected to the gas outflow hole 6a via the outflow groove 5b. Further, the cooling water passage 3 has a large number of parallel bottomed grooves 7 formed linearly in the left-right direction in FIG. 1, and the upstream side and the downstream side thereof are formed through water inflow grooves 8a and outflow grooves 8b. To the water inflow hole 9 and the water outflow hole 9a. As shown in FIG. 2, the cross-sectional shapes of the bottomed grooves 4 and 7 of the fluid passage 2 and the cooling water passage 3 are trapezoidal shapes in which the width S1 of the opening 10 is small and the width S2 of the bottom 11 is large. (Dovetail groove shape). In addition, 12 and 12a are a gas inflow hole and a gas outflow hole for the oxidizing gas.

The substrate (work) 1 configured as described above
In order to form the bottomed grooves 4 and 7 in advance, a masking process is performed in which a portion (non-processed portion) of the substrate 1 where a groove is not formed is previously covered with a mask material 13 (FIG. 3). The mask material 13
Any material can be used as long as it has good adhesion to the carbon plate of the substrate 1, but usually a resist film for photoprocessing is used. This film is coated on the substrate 1 and the arrangement pattern of the bottomed grooves 4 and 7 of the fluid passage 2 and the cooling water passage 3 is printed on the film. The masking process is completed by removing the material.

Next, as shown in FIG. 3, a flat soft backing member 16 is attached and fixed on a base plate 14 supporting a work such as a jig or a pallet with a lower adhesive 15a. Then, the masked work (substrate) 1 is attached and fixed on the soft backing member 16 by the adhesive 15b on the upper side. As the soft backing member 16, a polyurethane resin which supports the work 1 with appropriate rigidity and has physical properties effective for reducing the rebounding force of beads is preferable, but other synthetic resins having physical properties close to this are preferable. Polymer materials, for example, acrylic rubber,
Chloroprene rubber, acrylic resin, epoxy resin,
Nylon-based resin, phenol-based resin, and silicone-based resin can be used. As described above, the work 1 fixed on the base plate 14 is carried into a sand blasting machine by an appropriate handling device, and is mounted on the work table, and blast processing for forming the bottomed grooves 4 and 7 is performed. Will be applied.

In the above-mentioned blasting, the beads to be used may be irregular, cubic, rectangular, or polyhedral.
Any material may be used as long as it has a corner for shaving the carbon plate. The material is silicon carbide (SiC) or manganese oxide (MnO) in consideration of contamination of the carbon plate.
Is appropriate. Using beads (amorphous) with a particle size of 3 to 200 μm, a shot pressure of 1 kg /
Blasting is performed by uniformly spraying the beads on the carbon plate as the work 1 at a cm ^{2 to 5} kg / cm ² .

As a method of forming the bottomed grooves 4 and 7, a nozzle having an injection port having a width dimension W of the opening 10 of the groove or a slightly smaller dimension is used, and the nozzle is oriented perpendicular to the workpiece 1. While the beads are being sprayed in this state, the beads are moved in the groove forming direction (length direction) in accordance with the arrangement pattern of the bottomed grooves 4 and 7 to form a rectangular section having the width W and the depth H of the opening 10. A temporary groove A is formed. After a while
Using a small-diameter nozzle, the nozzle is inclined in accordance with the inclined side walls 10a, 10a of the bottomed grooves 4, 7, and in this state, the nozzle is moved in the direction in which the grooves are formed, so that the nozzles are provided on both sides of the temporary groove A. A wide groove B for completing the cross-sectional shape of the bottom groove is formed. Thus, the processing for forming the bottomed grooves 4 and 7 is completed.

In the above, the non-processed portion of the work 1 to which the mask material 13 is in close contact maintains the initial flat surface of the carbon plate by protecting the tip end surface of the work 1 by the mask material, while the mask material 13 is The grooved portions that are not in close contact are smoothly cut by the corners formed in the irregular shaped beads to form the required grooves. After the processing of the bottomed groove is completed, the work 1 is appropriately washed with an alkaline solution or the like, so that the polyurethane resin or the adhesive 1 of the soft backing member 16 is formed.
Dissolve and remove 5a, 15b and dry.

According to the method of forming the bottomed groove, the provisional groove A having a rectangular cross section having a width dimension equal to the width of the opening 10 of the bottomed groove is used in advance.
Is formed by the injection of beads from a nozzle directed perpendicularly to the work 1. However, since the soft backing member 16 is interposed on the back surface of the work 1, the beads are injected by the soft backing member 16. Since the impact on the work 1 due to the pressure is moderately buffered, the work 1 is not broken due to cracks in the bottom portion 11 thinned by the formation of the provisional groove A, and the provisional groove A is formed. When
The beads bounce off and scatter on the side wall of the temporary groove A, cracking the middle part of the side wall to break the work or break the opening 10 of the groove.
The bottomed grooves 4, 7 can be finished to an accurate cross-sectional shape without damaging the edge 10b.

The method of forming the bottomed grooves 4 and 7 is not limited to the above. For example, when forming the temporary groove A, instead of finishing the entire cross section of the temporary groove A in one step from one end to the end of the groove, the temporary groove A is divided into a plurality of sections in the depth direction, and the depth of the groove is gradually increased. The number of steps may be increased according to the number of sections, and the finishing may be performed. Using a small-diameter nozzle, the temporary groove A is divided into a plurality of sections on the left and right, the nozzle is repeatedly moved in the direction in which the grooves are formed by the number of times corresponding to the number of sections, and the processing is performed. May be formed, or after forming both the widened grooves B first, the remaining portions of the cross-sectional shapes of the bottomed grooves 4 and 7 may be formed. A method of forming a bottom groove can be employed.

In the above embodiment, the work 1 is fixed on the base plate 14 by the adhesive adhered to both sides of the soft backing member 16, so that the work 1 can be securely fixed and handled. Alternatively, the work 1 may be attached to the base plate 14 together with a soft backing member 16 having the lower surface thereof, using a fixture as appropriate.

In the above embodiment, the cross-sectional shape of the bottomed grooves 4 and 7 of the work 1 is trapezoidal in which the width of the groove on the opening 10 side is reduced. Is not limited to the above, and as shown in FIG.
It may have an inverted trapezoidal shape in which the width of the side is larger than that of the bottom portion 11a, or may have a rectangular shape, a triangular shape, an arc shape, or another shape. Also in the case of the bottomed groove shown in FIG. 4, as in the case of the trapezoidal bottomed groove, the provisional groove A1 is formed and then the widening groove B1 is formed to complete the bottomed groove 4a.
In addition, as shown in FIG. 5, the bottomed grooves 4b, 4
c is a bottom corner 4d on both surfaces 1a, 1b of the workpiece 1.
In the case where the members 4e are formed close to each other, the portions where the members 4e approach each other are thinned and easily broken. However, by using the soft backing member 16 as described above, damage to the work 1 can be prevented. The bottomed groove can be processed reliably without inviting.

Further, in the above-described embodiment, since the support plate such as a jig or a pallet is used as the base plate 14 for supporting the work 1, the work 1 can be easily handled, which is convenient. A processing table of a processing machine may be used. In the above embodiment,
Although the case where a straight bottomed groove is formed in the work 1 has been described, the bottomed groove is not limited to this and may be a curved or meandering groove.

Further, in the above-described embodiment, the case where the substrate of the fuel cell separator is used as the work 1 has been described. However, the present invention is not limited to this, and may be applied to a flat component of another product. Good. Furthermore, in the above-described embodiment, the case where a carbon plate is used as the work 1 has been described, but the present invention is not limited to this, and may be applied to stainless steel, titanium, and other metal plates.

[0022]

As described above, the first aspect of the present invention is:
A flat work with the unprocessed part covered with a mask material,
A soft backing member is interposed and fixed on the base plate, and a bottomed groove is formed by sandblasting in a required processing portion of the work. Therefore, when processing the bottomed groove by sandblasting, the soft backing member is used. As a result, the impact of the bead injection pressure on the work is moderately buffered, so that the work does not break from the part thinned by the formation of the groove with the bottom, and the groove wall surface of the bead that rebounds due to the formation of the groove Scattering is suppressed, and no cracks enter the groove wall surface. Therefore, the formation of the bottomed groove can be performed efficiently and accurately without eliminating processing defects.

According to the second aspect of the present invention, since the soft backing member is made of the polyurethane resin, the shock absorbing effect by the injection pressure of the beads is optimal, and the formation of the bottomed groove is further improved. It can be carried out. According to the third aspect of the present invention, since the work is fixed to the base plate with the adhesive adhered to both surfaces of the soft backing member, the work is closely fixed to the base plate together with the soft backing member. Thus, it is possible to easily handle a workpiece with a sand blasting machine or the like, and to perform machining of a bottomed groove with high accuracy.

According to the fourth and fifth aspects of the present invention, the bottomed groove has a cross-sectional shape different from that of the bottomed groove in that the groove width on the opening side and the groove width on the bottom side are different. In the case where the cross section in which the groove width on the opening side of the bottomed groove is small and the groove width on the bottom side is large is trapezoidal, the groove on the opening side Even when the edges and the grooves on both sides on the bottom side have an acute angle, the processing of the bottomed groove can be performed accurately and easily without any damage.

According to the sixth aspect of the present invention, after forming a temporary groove having a rectangular cross section having a width equal to the smaller dimension of the groove width, the bottomed groove is formed on the side of the temporary groove. Since the widened groove for completing the cross-sectional shape is formed, the processing of the groove with the bottom can be performed more smoothly and easily. Claim 7
According to the invention described in claim 8, the work is used as the substrate of the fuel cell separator, and is made of carbon.
Processing of a groove with a bottom on a thin brittle work can be performed safely and easily without causing damage to the work.

[Brief description of the drawings]

FIG. 1 is a front view showing a substrate of a fuel cell separator as an example of a work.

FIG. 2 is an enlarged cross-sectional view taken along the line II in FIG.

FIG. 3 is a sectional view showing an embodiment of the present invention.

FIG. 4 is a sectional view showing a case where the present invention is applied to a work having a groove with a bottom having another sectional shape.

FIG. 5 is a sectional view showing a sectional shape of another bottomed groove of a work.

[Description of Signs] A Temporary groove B Widening groove 1 Substrate (work) 2 Fluid path 3 Cooling water path 4,7 Bottomed groove 10 Opening 11 Bottom 13 Mask material 14 Base plates 15a, 15b Adhesive 16 Soft backing member

Claims (8)

[Claims] 1. A flat work in which a non-processed portion is covered with a mask material is fixed on a base plate with a soft backing member interposed therebetween, and a bottomed groove is formed in a required processed portion of the work by sandblasting. A method for processing a flat work. 2. The method according to claim 1, wherein the soft backing member is made of a polyurethane resin. 3. The method for processing a flat work according to claim 1, wherein the work is fixed to the base plate with an adhesive adhered to both surfaces of the soft backing member. 4. The flat plate according to claim 1, wherein the bottomed groove has a cross-sectional shape in which a groove width on an opening side and a groove width on a bottom side are different. Processing method for workpieces. 5. The method according to claim 4, wherein the cross section in which the groove width on the opening side is small and the groove width on the bottom side is large is trapezoidal. 6. A widening section for forming a temporary groove having a rectangular cross section having a width equal to the smaller dimension of the groove width, and then completing the cross sectional shape of the bottomed groove on a side portion of the temporary groove. The method according to claim 4 or 5, wherein a groove is formed. 7. The method for processing a flat work according to claim 1, wherein the work is a substrate of a fuel cell separator. 8. The method of processing a flat work according to claim 1, wherein the work is made of carbon.