JPH05307088A - Manufacture of watch crown - Google Patents

Abstract

PURPOSE:To manufacture a watch crown consisting of a spherical surface substantially with the skin knurled, with which the quality stability of the skin part is secured and the number of dies required to make shaping with forges is decreased. CONSTITUTION:A rod of round section as a material to be processed 1 is turning-machined into a preset length (Step 1), and the skin part is shaped with forging using dies 4 which is given a columnar form which is knurled 2 and whose one end consists of a spherical surface (Step 2). Then the mechanism part inside of the crown is turning-machined (Step 3), and finally the columnar periphery is processed with forging (Step 4).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a timepiece crown, and more particularly to a method for manufacturing a crown having a decorative groove pattern (hereinafter referred to as knurling).

[0002]

2. Description of the Related Art FIG. 2 shows a conventional method for manufacturing a timepiece crown, which shows a first step, in which a material 1 having a round cross section is turned into a T shape with a preset size. To do.
Shows a second step, in which the T-shaped upper surface skin portion of the processed material 1 that has been turned is formed by press forming the skin portion knurl 2 with a forming die having a forging forming function. Indicates the third step,
The skin part of the work material that was knurled in the previous step,
A spherical shape is formed by narrowing down with a diaphragm die having a diaphragm function. Shows a fourth step, in which a knurl is applied to the surface of the outer skin by forging with a bending die having a compression function. In a fifth step (not shown), the crown inner diameter groove is turned. In the sixth step (not shown), the outer periphery of the crown is ground. The method for manufacturing the crown of the spherical body is generally known as described above.

[0003]

However, in the conventional manufacturing method, the thin plate-shaped material to be processed is extremely compressed during the drawing process in the third step, and due to elasticity which is a characteristic of the metal material,
There is a problem that the dimensional variation of the outer diameter part occurs, and when the material to be processed is squeezed, there is a problem that a part of the material to be processed adheres to the die due to friction and causes a galling phenomenon on the skin part. This causes various quality problems such as the material to be processed in the formed skin is rolled and wrinkled. Further, in the conventional forging method, the cost is increased when manufacturing the mold, because it is composed of a plurality of molds having different functions. Therefore, an object of the present invention is to prevent the elasticity, adhesion, and rolling of the material to be processed and to reduce the number of molds in order to solve the conventional problems.

[0004]

In order to solve the above-mentioned problems, the present invention provides a method for manufacturing a timepiece crown.
By forming a columnar shape with one end having a knurled die side which is a forging pressure molding die component and a spherical surface, and having an appropriate length, by forging a workpiece material having a round cross section, The knurled and spherical multiple shapes are simultaneously formed on the skin, and then the functional parts inside the crown are removed by turning to prevent the occurrence of elasticity, adhesion, and rolling of the work material. ..

[0005]

In the method of manufacturing a timepiece crown having the above-described structure, the functional portion inside the crown is replaced with a turning process so that a forging pressure is applied to a work material having an appropriate length and a round cross section. Molding has become possible, and the knurling on the skin and the multiple shapes for the spherical surface have been singularized, eliminating the need for conventional drawing. As a result, the dimensional variation of the outer diameter portion due to the elasticity of the material to be processed, the galling phenomenon caused by sticking to the die, and the wrinkle state caused by rolling are prevented, and the quality is stabilized. Furthermore, in order to mold the knurled surface and the spherical surface of the skin, the number of molds required in plural was reduced to a single mold, and the mold manufacturing cost was reduced.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a method for manufacturing a timepiece crown of the present invention. In (Step 1), a bar material having a circular cross section, which is a material to be processed, is turned to a preset length by an automatic lathe (not shown). Cut by processing. In this case, the outer diameter of the material to be processed is set to the minimum size that can be inserted into the shape part of the die 4 of the forging press die.

In the second step, the cut workpiece material is a knurled hemispherical inner surface and a cylindrical inner surface continuous with the hemispherical inner surface, which is a component of a die having a forge forming function. It is inserted into a die 4 having a knuckle, and forged by a punch 3 to form a knurled surface and a spherical surface on the skin of the crown. After the press forming, the material to be processed is released from the knockout 5.

In (Step 3), the inside of the crown is hollowed out and turned by an automatic lathe (not shown). In this case, in order to prevent runout and flaws of the material to be processed, the gripping shape part of the chuck (not shown) used for gripping the crown which is the work at the time of turning is knurled, and one end has a spherical surface. The condition is that it should be a hollow that has the same shape as the skin of the crown and that has a cylindrical shape.

In step 4, a die 4 having a spherical inner surface with a knurled surface having the same shape as the skin of the crown and a punch 3 having a conical inner surface with a knurled surface are used to form a cylindrical crown outside the crown. By forging the diameter portion, the crown skin portion is formed into a roughly spherical body. After that (process 5)
Then, the mechanical part inside the crown is turned, and (process 6)
Then, polish the skin of the crown.

FIG. 3 is a perspective view of a timepiece crown obtained by the above-described manufacturing method, in which the button 7 and the winding stem 8 are attached to the completed crown 9 by caulking.

[0011]

As described above, according to the present invention, in a timepiece crown having a roughly spherical body in which a knurl is applied to the outer skin portion, a work material having an appropriate length and a circular cross section is provided on the knurl and one side. Forging is performed with a die having a cylindrical shape with the end part of which is a spherical surface, after which the mechanical part inside the crown is turned, and then the cylindrical outer diameter part is further forged. It has the effects described below. Knurl the skin and the spherical shape of one end,
Since the forging is performed simultaneously with the work material with a round cross section, the dimensional variation of the outer diameter part due to the elasticity of the work material, the galling phenomenon that occurs on the die, and the wrinkle state due to rolling are prevented, and the crown skin The quality of the department was stable. Knurl the skin and the spherical shape of one end,
By using a single mold, the number of molds required in the past was reduced, and the mold manufacturing cost was reduced.

[Brief description of drawings]

FIG. 1 is a process drawing showing the manufacturing method of the present invention. (Step 1) is an external perspective view of a material to be processed in turning the material to be processed of the timepiece crown of the present invention. (Step 2) is a cross-sectional view of press molding of the skin portion of the timepiece crown of the present invention. (Step 3) It is a cross-sectional view of the crown for turning the inner diameter mechanism portion of the timepiece crown of the present invention. (Step 4) is a cross-sectional view of outer diameter forging processing of the timepiece crown of the present invention. (Step 5) is a diagram of turning of the inner diameter mechanism portion of the timepiece crown of the present invention. (Step 6) It is a diagram of the appearance polishing of the timepiece crown of the present invention.

FIG. 2 is a process drawing showing a conventional manufacturing method. (Step 1) is an external perspective view of a material to be processed in conventional material turning of a timepiece crown. (Step 2) It is a cross-sectional view of knurling forging of a conventional timepiece crown. (Process 3) It is sectional drawing of the drawing process of the conventional timepiece crown. (Process 4) It is sectional drawing of the outer diameter forge processing of the conventional timepiece crown. (Step 5) It is a diagram of conventional inner diameter mechanism part turning of a timepiece crown. (Step 6) It is a diagram of external polishing of a conventional timepiece crown.

FIG. 3 is a perspective view of a timepiece crown according to the present invention.

[Explanation of symbols]

 1 Work Material 2 Knurl 3 Punch 4 Die 5 Knockout 6 Guide Plate 7 Button 8 Winding Machine 9 Crown

Claims (1)

[Claims] 1. A step of cutting a material having a circular cross section into a set length, and a die having a knurled hemispherical inner surface and a cylindrical inner surface continuous with the hemispherical inner surface,
The step of inserting the material to be processed into forging, the step of turning the inside of the material to be processed with the shaft portion left, and the step of knurling the same shape as the crown skin portion, and having a spherical inner surface And a step of forging the outer shape portion of the crown with a die and a punch having a conical inner surface to produce a substantially spherical crown.