JP5750305B2 - Anodized workpiece - Google Patents

Description

  The present invention relates to an alumite processed product in which a hard film is formed by anodic oxidation on the surface of a workpiece mainly composed of aluminum.

  For example, in products such as brake piston parts for automobiles and hydraulic control valves (spools) used in automatic transmissions for automatic cars, the durability, corrosion resistance, wear resistance, etc. of the aluminum alloy of the material (workpiece) are improved. In order to improve, an alumite processed product in which a hard coating treatment (anodizing treatment) that forms a hard coating by anodic oxidation on the surface of the workpiece is used (see, for example, Patent Document 1).

  In such an alumite processed product, a polishing process using a centerless polishing machine or the like is usually performed in order to adjust the product dimensions after the hard coating treatment. However, the hard coating formed on the surface of the anodized workpiece is a porous coating composed of fine pores that grow in a direction substantially perpendicular to the surface of the workpiece. Therefore, as shown in FIG. 8, a non-growth portion S in which a gap is formed without forming the coating layer 130 is formed in the corner portion (projection corner portion) 122 protruding toward the outside of the main body 121 of the workpiece 120. There has been a problem that the hard coating layer 130 is missing from the non-growth portion S at the time of contact with a grindstone or other workpiece when performing polishing or the like. In particular, in an anodized workpiece with chipping, when used for parts that require precision such as a hydraulic control valve (spool), it may cause malfunctions such as causing malfunction of the automatic transmission. The yield was lowered and it was economically disadvantageous.

Japanese Patent Laid-Open No. 5-118458

  This invention is made | formed in view of the said point, and provides the alumite processed material with which the hard film formed in the projecting angle part of a workpiece is hard to chip.

  That is, according to the first aspect of the present invention, a concave portion having a circular arc shape when viewed from the side is formed at a projecting angle portion of a workpiece mainly composed of aluminum, and a hard coating layer is formed on the surface of the workpiece including the concave portion by anodization. The present invention relates to an anodized workpiece characterized by being a reinforced projecting angle portion.

  According to a second aspect of the present invention, there is provided the anodized workpiece according to the first aspect, wherein the concave portion having an arc shape when viewed from the side is a fan-shaped concave portion having a radius of 0.03 to 5.0 mm.

  The invention according to claim 3 relates to the anodized workpiece according to claim 1 or 2, wherein the apex of the recess of the workpiece is cut into a tapered portion inclined in a side view or an arc-shaped recess in a side view. .

  The invention according to claim 4 relates to the anodized article according to any one of claims 1 to 3, wherein the film thickness of the hard coating layer is 10 to 100 μm.

  The anodized workpiece according to the invention of claim 1 is formed with a concave portion having an arc shape in a side view at a projecting angle portion of a workpiece mainly composed of aluminum, and a hard coating layer formed by anodization on the surface of the workpiece including the concave portion. Since the reinforced protrusion angle portion is formed, an excellent chipping suppression effect can be obtained.

  The invention of claim 2 can obtain a better chipping suppression effect in claim 1 because the arc-shaped recess in side view is a fan-shaped recess having a radius of 0.03 to 5.0 mm.

  A third aspect of the present invention is the chip 1 or the second aspect according to the first or second aspect, since the apex portion of the concave portion of the workpiece is cut into a tapered portion inclined in a side view or a concave portion having an arc shape in a side view. Can be improved.

  According to a fourth aspect of the present invention, since the hard coating layer has a thickness of 10 to 100 μm in the first to third aspects, performances such as durability, corrosion resistance, and wear resistance can be sufficiently obtained and economical. Is also advantageous.

It is a side view of the alumite processed material which concerns on one Example of this invention. It is a schematic sectional drawing of the vicinity of the protrusion angle part of the workpiece in which the fan-shaped protrusion part was formed. It is a schematic sectional drawing of the strengthening protrusion angle | corner vicinity of an alumite processed material. It is a schematic sectional view of the vicinity of the reinforced projecting angle portion of the anodized workpiece in which the fan-shaped projecting portion centered on the outer side from the apex portion of the projecting angle portion is formed. It is a schematic sectional view of the vicinity of the projecting angle portion of the anodized product in which the projecting angle portion of the workpiece is formed in the tapered portion or the chamfered portion. FIG. 5 is a schematic cross-sectional view in the vicinity of a projecting angle portion of a workpiece in which a tapered portion or a recess is formed at the apex of the recess. It is a schematic sectional drawing of the protrusion angle | corner vicinity of the anodized workpiece in which the eccentric recessed part was formed. It is a schematic sectional drawing of the protrusion angle | corner vicinity of the conventional alumite processed material.

  An anodized workpiece 10 according to an embodiment of the present invention shown in FIG. 1 is formed with a concave portion 23 having an arc shape in a side view formed at a projecting angle portion 22 of a workpiece 20 mainly composed of aluminum, and including the concave portion 23. A hard coating layer 30 is formed on the surface of the workpiece 20 by anodic oxidation to form a reinforced protrusion 40.

  The workpiece 20 is made of aluminum alone or an appropriate aluminum alloy, and as shown in FIG. 2, is formed into a predetermined product shape having at least one projecting corner 22 that is a corner projecting toward the outside of the main body 21. Is done. When machining into a predetermined shape, the projecting angle portion 22 is formed in the concave portion 23 having a circular arc shape when viewed from the side by a known cutting device or the like.

  The hard coating layer 30 is a porous oxide coating composed of fine pores formed on the surface of the workpiece 20 by anodizing the workpiece 20 mainly composed of aluminum with an electrolyte such as dilute sulfuric acid. This improves the durability, corrosion resistance, wear resistance, and the like of the workpiece 20. The film thickness of the hard coating layer 30 is preferably 10 to 100 μm. When the film thickness is smaller than 10 μm, effects such as durability, corrosion resistance, and abrasion resistance are insufficient. Further, when the film thickness is larger than 100 μm, there is a problem in terms of dimensional accuracy and price.

  As shown in FIG. 3, the reinforced projecting angle portion 40 is formed by forming a hard coating layer 31 on the surface of the concave portion 23 having a circular arc shape when viewed from the side of the workpiece 20. In the reinforced protrusion 40, a dense coating is formed in the concave portion 23 having a circular arc when viewed from the side due to volume expansion during the generation of the hard coating layer 31. Therefore, the non-growth part S, which is a gap in which no coating layer is formed, is not formed in the hard coating layer 31 on the surface of the recess 23, and the boundary between the hard coating layer 31 on the surface of the recess 23 and the hard coating layer 32 on the surface of the main body 21. The non-growth part S can be reduced, and the strength of the hard coating layer 30 such as wear resistance and impact resistance is improved. In addition, since the reinforced protrusion 40 is formed in a side-view arc shape that is substantially the same shape as the side-arc-shaped concave portion 23, it is difficult for other objects to physically contact. By these, generation | occurrence | production of the chip | tip in the protrusion part 22 of the hard film layer 30 can be suppressed effectively.

  As shown in FIG. 2, the anodized workpiece 10 is preferably a fan-shaped recess 23 </ b> A having a radius of 0.03 to 5.0 mm with the apex 22 </ b> A of the projecting corner 22 as the center. When the radius of the fan-shaped concave portion 23A is smaller than 0.03 mm, the shape of the reinforced protrusion angle portion 40 does not become an arc shape when viewed from the side, and a sufficient chip suppression effect cannot be obtained. If the radius of the fan-shaped recess 23A is larger than 5.0 mm, a sufficient chipping suppression effect cannot be obtained, for example, the surface of the reinforced projecting angle portion 40 is widened and other objects are easily brought into physical contact. Moreover, if it is set as the fan-shaped recessed part 23A with a radius of 0.1-0.5 mm, the more outstanding chip | tip suppression effect can be acquired. Furthermore, as shown in FIG. 4, a good chipping suppression effect can be obtained even with a fan-shaped recess 23B having a center 22B outside the apex 22A of the projecting angle portion 22. In the fan-shaped recess 23B, the radius is 0.03 to 5.0 mm (more preferably 0.1 to 0.5 mm), and the center distance from the apex 22A of the projecting corner 22 is less than the radius.

Next, specific examples of the alumite processed product of the present invention will be described. In the following examples, A6061-T6 as a workpiece is processed into a bulb shape having a diameter of 12 mm, the shape of the projecting angle portion is adjusted, and anodization is performed to form a hard coating layer with a film thickness of 60 μm and a hardness of about 350 Hv. Hydraulic control control valves for the automatic transmissions of prototype examples 1 to 7 were created. The conditions of the anodizing treatment are 78 minutes at 5 ° C. and a current density of 2.2 A / dm ² with the workpiece as an anode in a sulfuric acid bath of 15 to 20%.

  Prototype Example 1 is a valve having a concave portion 23 (fan-shaped concave portion 23A) having a radius of 0.2 mm as shown in FIG. 4 is a valve of a concave portion 23 (fan-shaped concave portion 23B) having a radius of 0.2 mm connecting a position of 0.1 mm from the apex portion 22A of the projecting angle portion 22 shown in FIG. 4, and Prototype Example 3 is an example of the projecting angle portion 50A of the workpiece 20A. 5A is a valve having a tapered portion 51 in which a portion of 0.1 mm is cut out from the apex portion of the projecting angle portion 50A shown in FIG. 5A, and prototype 4 shows the shape of the projecting angle portion 50A of the workpiece 20A. 5 (a) shows a valve having a tapered portion 51 in which a portion of 0.15 mm is cut out from the apex portion of the projecting angle portion 50A. In the prototype 5, the shape of the projecting angle portion 50B of the workpiece 20B is shown in FIG. The valve of the chamfered portion 52 chamfered with a radius of 0.1 mm from the apex of the projecting angle portion 50B shown in Sample 6 is a valve of the chamfered portion 52 in which the shape of the protruding portion 50B of the workpiece 20B is chamfered with a radius of 0.15 mm from the apex of the protruding portion 50B shown in FIG. It is the conventional valve | bulb of the corner | angular part which the shape of the protrusion 122 of the workpiece 120 protruded toward the outer side shown in FIG.

  Therefore, for Prototype Examples 1 to 7, 9 valves are prepared for each prototype, and each stage of the prototype is alternately stacked in two stages on a known vibration sieving device and vibrated for 3 minutes with an amplitude of 0.5 mm. (Good product rate) was confirmed visually.

  For Prototype Example 1, the yield rate was 87.5%. For Prototype Example 2, the yield rate was 75%. For Prototype Example 3, the yield rate was 37.5%. For Prototype Example 4, the yield rate was 37.5%. For Prototype Example 5, the yield rate was 0%. For Prototype Example 6, the yield rate was 62.5%. For Prototype Example 7, the yield rate was 0%.

  As shown in the results of Table 1, Prototype Examples 1 and 2 in which the shape of the projecting angle portion 22 of the workpiece 20 is a valve of the concave portion 23 are good, and in particular, Prototype Example 1 is a valve of the fan-shaped concave portion 23A. Was the best. On the other hand, in prototype examples 3 and 4 in which the shape of the projecting angle portion 50A of the workpiece 20A is the tapered portion 51, the boundary between the hard coating layer 36 of the tapered portion 51 and the hard coating layer 32 on the surface of the main body 21 is not. Since the growth part S was relatively large, good results were not obtained. In Prototype Examples 5 and 6 in which the shape of the projecting angle portion 50B of the workpiece 20A is the chamfered portion 52, a large number of non-growth portions S are formed on the hard coating layer 37 of the chamfered portion 52 and the chamfered portion 52 is formed. Since the non-growth portion S is formed at the boundary between the hard coating layer 37 of the portion 52 and the hard coating layer 32 on the surface of the main body 21, good results were not obtained. Note that, in Prototype Example 7 which is a conventional product, the non-growth portion S of the projecting angle portion 122 was very large, and thus a good result was not obtained.

  Subsequently, 500 each of the first prototype example 1 which is a valve of the fan-shaped recess 23A and the prototype example 7 which is a conventional product are prepared, aligned by a parts feeder, and then introduced into a known centerless polishing machine. Polishing was performed at 30 to 50 μm and the presence or absence of chipping was visually observed to determine the number of defective products and the ratio of defective products (defective rate) to the entire valve (500).

  For Prototype Example 1, the number of defective products was only 1 out of 500, and the defective rate was 0.2%. On the other hand, in Prototype Example 7, the number of defective products was 25 out of 500, and the defect rate was 5%.

  As shown in the results of Table 2, in the prototype 1 in which the shape of the projecting angle portion 22 of the workpiece 20 is a valve of the recess 23, the defect rate is significantly higher than that in the prototype 7 which is a conventional valve. I found it improved.

  As illustrated and described above, in the anodized workpiece of the present invention, a concave portion having a circular arc shape when viewed from the side is formed at a projecting angle portion of a workpiece mainly composed of aluminum, and the surface of the workpiece including the concave portion is anodized. By forming the hard coating layer by the reinforced projecting angle portion, the occurrence of non-growth portions is greatly suppressed, and other members from the viewpoint of the shape of the projecting angle portion and the strength of the hard coating layer Therefore, it is possible to effectively cope with the physical contact with the material, so that an excellent chipping suppression effect can be obtained. Therefore, the yield can be improved and the manufacturing cost can be reduced as compared with the conventional case.

  The anodized product of the present invention is not limited to the above-described embodiments, and can be implemented by appropriately changing a part of the configuration without departing from the spirit of the invention. For example, as shown in FIG. 6, the apex portion 24 of the recess 23 of the workpiece 20 may be cut into a tapered portion 25 </ b> A that is inclined when viewed from the side or a recess 25 </ b> B that is arc-shaped when viewed from the side. The shape of each apex 24, 24 of the recess 23 may be a combination of a tapered portion 25A and a recess 25B as shown, or only one of them. Thereby, it becomes possible to further reduce the non-growth portion (S) at the boundary between the hard coating layer (31) on the surface of the recess 23 and the hard coating layer (32) on the surface of the main body 21, and further improve the chipping suppression effect. be able to.

  In addition, in the example, the protrusion corner portion vertex of the workpiece and each vertex of the concave portion having a circular arc shape when viewed from the side are approximately equidistant. However, as shown in FIG. The center position 22C of the recess 23 may be decentered in the desired direction to form the recess 23C having an arc shape when viewed from the side. In the anodized workpiece in which the eccentric recess 23 is formed, the non-growth portion S1 on the eccentric side (in the illustrated example, the side surface 21A of the main body) is reduced, so that the hard coating layer 30 near the apex 24A on the eccentric side is missing. This can be effectively suppressed, and is particularly effective in preventing chipping only on the one surface 21A side of the main body 21.

DESCRIPTION OF SYMBOLS 10 Alumite processed material 20 Workpiece material 22 Projection angle part 23 Side surface circular-arc-shaped recessed part 30 Hard coating layer 40 Strengthening projection angle part

Claims (4)

  A concave portion having a circular arc shape when viewed from the side is formed in the projecting angle portion of the workpiece mainly composed of aluminum, and a hard coating layer by anodization is formed on the surface of the workpiece material including the concave portion to form a strengthened projecting angle portion. Anodized product characterized by that.   The anodized workpiece according to claim 1, wherein the concave portion having an arc shape when viewed from the side is a fan-shaped concave portion having a radius of 0.03 to 5.0 mm.   The anodized workpiece according to claim 1 or 2, wherein a vertex of the concave portion of the workpiece is cut into a tapered portion that is inclined in a side view or a concave portion that has an arc shape in a side view.   The anodized product according to any one of claims 1 to 3, wherein the hard coating layer has a thickness of 10 to 100 µm.

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