JPH01317646A - Production of hand for timepiece - Google Patents

Abstract

PURPOSE:To reduce the man-hours for working and assembling by subjecting a band material to surface finishing, then simultaneously subjecting the material to curved surface forming and blanking back of outside shapes by a press blanking die of a male die the front end of which has a curved recess shape and forming a coating finish layer on the surface. CONSTITUTION:The band material 1 consisting of copper or brass is continuously pressed and is thereby formed with pipe holes 2, pilot holes 3, relief holes 4a, 4b, and projections 5. The surface part of the material 1 is subjected to surface finishing 6 such as buffing to a specular surface. The material 1 is pressed by the external press blanking die of the male die 7 the front end 7a of which has the curved projecting shape, by which the curved surface forming and blanking back of the outside shapes of the hand 11 for timepieces are simultaneously executed. The relief holes 4a are provided to prevent the deformation of the material 1 at the time of the external blanking back of the hand 11 and the relief holes 4b are provided in order to allow the easy back of the material 1 at the time of the blanking back. The coating finish layer is thereafter formed on the material. The hand is supplied in the state of being blanked back into the band material to an assembling stage in this way and, therefore, the flawing by transportation is prevented and the man-hours for working and assembling are reduced.

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method for manufacturing a watch hand. [Prior art] Conventionally, when using a watch with a curved pointer (round shape),
The manufacturing method for the minute hand is to continuously press a strip of non-ferrous metal such as copper alloy to punch a pilot hole, a square hole, and an escape hole in order, and then shape the strip including the square hole into a curved shape (round The pointer part was formed into a curved shape (instep round shape) by surface pressing using a press surface pressing mold having a metal mold equipped with a carbide material member having a mirror-like concave portion. After that, the pressed surface part is buffed to a mirror surface, the outer shape of the hands is pressed out, and a coating finish layer is formed on the pressed hands by plating, painting, etc. to complete the hour and minute hands. was.

[Problem to be solved by the invention]

However, the above-mentioned conventional clock hour and minute hands have the following problems. (1) The member that is attached to the square press die and forms the pointer into a curved shape (round shape) is made of an expensive carbide material. In addition, to form a curved (round-shaped) recess in a carbide material, it must be processed by electric discharge machining, which requires heavy processing equipment, and it is difficult to make a rough electric discharge machined surface into a mirror surface. Since this requires a huge amount of research time, an expensive press die is required, which increases the cost of the guideline. (2) Furthermore, since the finished hour and minute hands for one watch are made as a single unit, scratches occur during transportation to the watch assembly process, and separation and sorting using a parts feeder is required during the automatic assembly process, which increases costs. It had become. (3) Recently, there has been a movement to make the display mechanism including the pointer thinner, and as a result, the thickness of the pointer has also become thinner. Even if surface pressing is applied to the thin strip of raw material, the amount of movement of the raw material is small, and the curved surface shape with a small curvature (
This makes it difficult to manufacture hour and minute hands for watches with high-quality hands that have a thick, three-dimensional feel. Therefore, the present invention is intended to solve these conventional problems, and its purpose is to create a high-quality pointer section with a three-dimensional feel and a thickly curved surface shape (round shell shape) that can be adapted to thinner watches. It is a place that provides low-cost pointers for your watches. [Means for Solving the Problems 1] In order to solve the above-mentioned problems, the present invention has been completed, and provides a method for manufacturing a watch hand in which a metal strip is continuously pressed to form a hole. A step of applying a surface finish such as buffing or diamond cutting to the surface portion of the band material including the hole-shaped holes, and a step of cutting out the outer shape of the portion of the band material including the hole-shaped holes using a press having a rounded shape with a curved convex tip. A step of simultaneously forming the curved surface of the watch hand and extracting the outer shape by pressing with a mold, and forming the hole 1
A process of forming a coating finish layer by plating, painting, etc. on the surface of the band material containing the watch pointer whose curved surface has been molded and the outer shape has been extracted, and removing the watch pointer from the band material on which the coating finish layer has been formed. It is characterized by consisting of a process. [Example] Below, an example of the present invention will be explained in detail based on the drawings. Figure 0 shows the present invention in the order of steps. FIG. 1 is a partial plan view of a pressed band material according to an embodiment of the present invention, in which a copper or brass band material L is continuously pressed to form a hole 2, a pilot hole 3, and a relief hole. hole 4
a, 4b, and protrusion 5 are formed. The hook hole 2 is fitted into the pointer shaft of the watch mechanical body, and the precision of the hook hole 2 is the same as that of the conventional one. The pilot hole 3 is used for positioning during post-processing, and is used in conventional continuous press processing. Figure 2 shows II-II in Figure 1.
A line cross section is shown, and the hole 2 is bent downward. FIG. 3 shows a cross section taken along the line ■-III in FIG. 1, in which the protrusion 5 is formed. The protrusion 5 will be described later. FIG. 4 is a partial plan view of the strip material which has been surface-treated in FIG. 1, and after the above-mentioned press working, the surface portion of the strip material 1 including the hole 2 is buffed. Surface finish 6 such as diamond cutting is applied to make it mirror-like. Since buffing and diamond cutting are performed on the strip material, no chattering occurs even if the strip material is thin, and the processing load is reduced. FIG. 5 is a partial cross-sectional view of the surface-treated strip material in FIG. 4 placed in an outline cutting die, and 7 is a tip 7a
The tip 7a of the 0-year-old type 7 has a convex curved O type, 8 is a medium type, 9 is a stripper, and 1O is a knockout.A recess 7b is provided at the tip 7a of the 0-year-old type 7, through which the hollow part escapes during press forming. FIG. 6 is a partial cross-sectional view of the band material in which the curved surface forming process of the watch hand and the extraction process of the outer shape are simultaneously performed on the band material in FIG. 1 is continuously pressed using a press outer shape cutting die having a rounded shape 7 with a tip 7a having a curved convex shape to simultaneously form the curved surface of the watch hand 11 and extract the outer shape. As a result, the watch pointer 11 is formed into a curved surface that follows the curved convex shape of the tip 7a of the round die 7 of the press outer shape cutting die, and the watch pointer 11 is pulled back into the band l by the knockout 10. There is. FIG. 7 is a partial plan view of the band material in which the curved surface forming process of the watch hand and the extraction process of the outer shape were simultaneously performed on the band material in FIG.
The watch hand 11 is continuously pressed using a press outer die having a rounded shape 7 whose tip 7a has a curved convex shape.
The escape hole 4a is provided for the purpose of preventing the band l from being deformed when the outer shape of the timepiece pointer 11 is removed. A pointer 11 is provided for the purpose of making it easier to return to the strip l when removing the outer shape. In the embodiment, the escape hole 4b was provided so as to be in contact with the end portion 11a of the outer shape of the timepiece pointer 11.
This escape hole 4b and the end portion 11 of the outer shape of the watch hand 11
A similar effect can be obtained even if the distance from a is set to 5/100 to 10/100 mm. Figure 8 shows a cross section along the line V■-■ in Figure 7,
After the above-mentioned curved surface molding and outer shape extraction processing, a covering finishing layer 1 is applied by plating, painting, etc. on the surface of the band l containing the watch hand 11 whose curved surface 21 has been molded and the outer shape has been extracted.
2 is formed. It is also possible to form a coating finishing layer 12 on the surface of the band material 1 and then continuously apply a printed line on the center line of the needle body in the state of the band material by printing. Finally, the watch pointer 11 is removed from the band material 1 containing the watch pointer 11 from which the hook hole 2 and the outer shape have been removed, and the watch pointer 11 is completed. A plan view of a completed watch hand is shown. To remove it, you can bend the band 1 (or press the watch pointer 11 lightly from above) (either method allows you to easily remove the watch pointer 11 from the band 1. After the pointer 11 is pulled back into the band 1, it is also possible to transport the band 1 to the watch assembly process with the coating finishing layer 12 formed on the surface of the band 1. The protrusions 5 may be hoop-shaped or short, and their shapes can vary depending on the automatic assembling method of the watch.The protrusions 5 are provided to prevent scratches on the finished surface due to overlapping at this time. Figure 3 shows the first
The figure shows a cross section taken along the line ■[-■l, and the convex portion of the protrusion 5 is provided on the finished surface side, but the same effect can be obtained even if it is provided on the back surface side. FIG. 10 is a cross-sectional view of the completed watch hand shown in FIG. 9, in which a surface finish 6 is provided on the upper surface of a brass metal material 13, and a coating finish layer 12 is formed on the upper and lower surfaces thereof. [Effects of the Invention J As explained above, according to the present invention, a watch hand whose pointer part has a curved shape (instep round shape) is continuously surface-finished in the form of a band material, and then the pointer has a curved tip. After forming the pointer's curved surface and punching out the outer shape simultaneously by pressing with a press outer shape cutting die having a convex shape, the coating finish layer is formed, resulting in the following effects. was gotten. (1) The pressing mold equipped with expensive carbide material, which requires heavy processing equipment and an enormous amount of processing time, as in the past, is no longer necessary, and the pressing process can also be omitted. (2) Since the curved surface forming process of the pointer part is a bending process, a curved surface shape (instep round shape) that is thicker and has a smaller curvature can be obtained than a surface stamped product with the same needle thickness. (3) Since it is possible to supply the timepiece pointer to the timepiece assembly process in a state in which it has been pulled back into the band material, it is possible to prevent the timepiece pointer from being scratched during transportation. or,
In the automatic assembly process, separation and sorting using a parts feeder are no longer necessary, reducing assembly man-hours. In this way, it has a high-quality pointer section with a thick three-dimensional feel that can be adapted to thinner watches, and the number of man-hours for processing and assembly can be significantly reduced, making it possible to provide inexpensive watch hands. .

[Brief explanation of the drawing]

FIG. 1 is a partial plan view of a pressed band material showing an embodiment of the present invention, and FIG. 2 is a section II-II in FIG. 1.
3 is a sectional view taken along the line III-III in FIG. 1, FIG. 4 is a partial plan view of the strip material that has been surface-treated in FIG. 1, and FIG. Partial cross-sectional view of a state in which the strip material subjected to
The figure is a partial cross-sectional view of a state in which the curved surface forming process of the watch hand and the extraction process of the outer shape are simultaneously performed on the band material in FIG. 4. Fig. 7 is a partial plan view of the band material in which the curved surface forming process of the watch hand and the extraction process of the outer shape were simultaneously performed on the band material in Fig. 4, and Fig. 8 is the ■-VU#ji! in Fig. 7! Cross-sectional view. Figure 9 is a plan view of the completed watch hand, Figure 1O is the 9th
It is a sectional view taken along the line XX in the figure. l... Band material 2... Hakama hole 3... Pilot hole 4a, 4b... Relief hole 5... Protrusion 6... Surface Finished surface 7...Silver type 8...Medium type 9...Stripper lO...Knockout 11...Clock pointer 12... ...Coating finishing layer 13...Metal material or more Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10

Claims (2)

[Claims] (1) In a method for manufacturing watch hands in which a metal strip is continuously pressed to form a hole, the step of applying a surface finish such as buffing or diamond cutting to the part of the band that includes the hole. and a step of simultaneously performing the curved surface forming process of the watch hand and the process of extracting the external shape by pressing the part of the band material including the hole with a press external shape cutting die having an O type with a curved convex tip. a step of forming a coating finish layer by plating, painting, etc. on the surface of the band material including the watch hand which has been subjected to the above-mentioned hole, curved surface molding process, and extraction process of the outer shape; and a process of forming a coating finish layer by plating, painting, etc. A method for manufacturing a watch pointer, comprising the steps of: removing the watch pointer from a piece of material. (2) Before the step of applying the surface finish of the watch hand,
The watch hand according to claim 1, characterized in that the part of the band material including the hole is continuously pressed to provide a plurality of protrusions and relief holes at the end portions of the outer shape of the watch hand. Production method.