JPH0222157B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing an outer cutter for an electric shaver, in which a conductive substrate on which a resist is formed at a position corresponding to the hair introduction hole of the outer cutter is subjected to primary electroforming, and then a drawing process is performed. After that, it is formed into a spherical shape and then subjected to secondary electroforming.

Electroforming is known as a manufacturing method for this outer cutter.
FIG. 5 shows a cross section of this type of outer cutter being manufactured by a conventional method, in which a resist b is formed at a position corresponding to the whisker introduction hole of the outer cutter of a flat conductive substrate a, and a master mold A This is formed into a spherical shape with a predetermined curvature by drawing, and then primary electroforming is performed on the outer convex part to form primary electroforming c, and after peeling treatment, secondary electroforming is performed. Then, a secondary electroformed layer d was formed, and the secondary electroformed layer d was peeled off to obtain a spherical outer cutter substrate. However, in this conventional method, the primary electroforming was performed after the matrix A was formed into a spherical shape by a drawing method, so that the center (top) of the main surface of the matrix A was closer to the electrode, and the precipitated ions were Therefore, the thickness of the secondary electroformed layer d is the maximum thickness T at the center (apex), and gradually becomes thinner as it moves away from the center until the secondary electroformed layer d at the outermost periphery. The thickness t of the center becomes much thinner than that of the center. By the way, as shown by the solid line in Figure 6, this kind of outer cutter has a central part with reduced rigidity to give sufficient flexibility to ensure adhesion to the skin surface, and a peripheral part that is attached to the central part. It is desirable to provide greater rigidity to ensure strength, but since the outer cutter manufactured by the above conventional method is thicker towards the center, sufficient flexibility is ensured at the center as shown by the dotted line. In addition, there was a drawback that the peripheral part lacked rigidity, making it weak in terms of strength. Furthermore, when primary electroforming is performed after drawing the flat substrate a, the ends of the resist b peel off from the substrate a due to the drawing, as shown in FIG.
There were drawbacks such as precipitated ions penetrating and electrodepositing between the formed edges, causing an overhang c' in the primary electroformed layer c, and also causing distortion in the outer cutter being formed.

Therefore, the present invention was made for the purpose of providing a method for manufacturing an outer cutter that eliminates the drawbacks of the conventional method, and in which a primary voltage is applied to a conductive substrate on which a resist is formed at a position corresponding to the whisker introduction hole of the outer cutter. After casting, drawing is performed to form a spherical shape, and then secondary electroforming is performed to form the outer cutter. The resist is finished thinly and the edges of the resist do not peel off from the substrate during drawing.

Hereinafter, the method for manufacturing an outer cutter according to the present invention will be explained in order of steps with reference to the drawings.

FIG. 1 is a cross-sectional view of the mother die, and the mother die 1 is located at a position corresponding to the hair introduction hole of the outer cutter on the upper surface of a flat substrate 2 made of a conductive thin metal plate such as a nickel plate or an aluminum plate. , by forming a thin film resist 3 made of an electrically insulating material. 2a is the substrate 2
This is the exposed surface on which the resist 3 is not formed. There are various ways to form the resist 3, but for example, a thin layer of UV resin is applied to the top surface of the substrate 2, a pattern sheet with a net blade pattern is placed on top of it, and ultraviolet rays are irradiated to fill the hair introduction holes of the outer blade. It is formed by curing the corresponding portion and then eluting the uncured portion.

Figure 2 shows the mother mold 1 formed in this way, which is immersed in an electrodeposition bath (not shown) and subjected to primary electroforming. 2
Precipitated ions are electrodeposited on the exposed surface 2a excluding the resist 3 to form the primary electroformed layer 4. Electroforming is performed until the electroformed layer 4 grows to have a thickness equal to or greater than that of the resist 3 and covers the upper peripheral edge of the resist 3. If primary electroforming is performed before drawing in this way, the distance from the electrode of the flat substrate 2 is equal over the entire surface, so the precipitated ions will be electrodeposited uniformly on the exposed surface 2a. , primary electroformed layer 4
All have the same thickness, and the center part is not thicker than the peripheral part as in the conventional case.

Once the primary electroformed layer 4 has been formed, it is peeled off by immersion in an aqueous solution of potassium dichromate or the like, and then drawn. FIG. 3 shows a cross-sectional view of the drawing process, in which 5 is a male die having an outwardly convex spherical tip surface, 6 is a female die having a center opening corresponding to the male die 5, and primary electroforming The mother mold 1 is installed so that the layer 4 is located on the opposite side of the male mold 5, and the male mold 5 is pushed into the female mold 6 to form the mother mold 1 into a spherical shape. At this time, since the primary electroformed layer 4 is fixed to the substrate 2 so as to cover the peripheral edge of the upper surface of the resist 3, the end portion of the resist 3 does not peel off from the substrate 2.

After the drawing process is completed, the master mold 1 is immersed in the electrodeposition bath again to perform secondary electroforming, and a secondary electroformed layer 7 is formed on top of the primary electroformed layer 4 to a predetermined thickness. (See FIG. 4) Once the electroforming is completed, the secondary electroformed layer 7 is peeled off to complete the production of the outer blade substrate. The thickness of the center part (top part) of the outer cutter board formed in this way is much thinner than that of the conventional one, and as shown by the chain line in Figure 6, it approaches the ideal curve and the rigidity of the center part is reduced. is considerably improved, and there is almost no distortion. In the above embodiments, the peeling process is performed prior to the drawing process, but it may be performed after the drawing process.

As explained above, the present invention applies primary electroforming to a matrix 1 formed by applying an electrically insulating resist 3 to the positions corresponding to the whisker introduction holes of the outer cutter of a flat conductive substrate 2, thereby removing the resist. Primary electroformed layer between 3 and 4
After forming, the mother mold 1 is formed into a spherical shape by drawing, and then secondary electroforming is performed to form a secondary electroformed layer 7 on the upper surface of the primary electroformed layer 4. Therefore, the wall thickness at the center of the outer cutter can be made considerably thinner than conventional ones, and an extremely precise finish without distortion can be expected. It has the advantage that it makes good contact with the surface, has sufficient strength at its periphery, and has no risk of fatigue failure due to long-term use.

[Brief explanation of drawings]

The figure shows an embodiment of the present invention.
The figure is a sectional view of the mother die, Figure 2 is a sectional view of the mother die subjected to primary electroforming, Figure 3 is a sectional view during drawing, and Figure 4 is a sectional view of the mother die after primary electroforming.
The figure is a cross-sectional view of the mother mold subjected to secondary electroforming, Figure 5 is a cross-sectional view during manufacturing by the conventional method, Figure 6 is a graph showing the elastic properties of the outer cutter, and Figure 7 is manufactured by the conventional method. It is a sectional view inside. 1... Mother mold, 2... Conductive substrate, 3... Resist, 4... Primary electroformed layer, 7... Secondary electroformed layer.

Claims (1)

[Claims] 1 A mother mold 1 formed by applying an electrically insulating resist 3 to a position corresponding to the whisker introduction hole of the outer blade of a flat conductive substrate 2 is subjected to primary electroforming to form the resist 3.
After forming the primary electroformed layer 4 between them, the mother mold 1 is formed into a spherical shape by drawing, and then secondary electroforming is performed to form a secondary electroformed layer on the upper surface of the primary electroformed layer 4. 7. A method for manufacturing an outer blade of an electric razor.