JPS5863063A - Rotor of step motor for watch and manufacture therefor - Google Patents

Abstract

PURPOSE:To reduce the number of parts and to eliminate the occurrence of flux or the like of a rotor permanent magnet by a method wherein parts such as a rotor pinion, and a rotor permanent magnet are integrally insert-molded by a high-molecular material. CONSTITUTION:A rotor core 10 is driven in a hoop carrier 30 punched pilot holes 30a and driving holes 30b and a previously magnetized rotor permanent magnet 2 is incorporated. Next, an electromagnet or a permanent magnet is arranged in a molding metal mold 5 or at a platen section located immediately before the outside of the molding metal mold 5 and a centering to the molding metal mold 5 is done by applying a magnetic field to the rotor permanent magnet 2. Assembled rotor stem 10 and the rotor permanent magnet 2 are unitedly inserted and molded by a high-molecular material, for example, thermoplastic resin such as hard plastic and a rotor is obtained. A pinion section 40a is composed by molding.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a structure of a rotor used in a step motor for a watch and a method of manufacturing the rotor.

Conventionally, in this type of rotor in a step motor for a watch, the following steps have been taken to incorporate a rotor magnet made of sintered material into a rotor pinion. 1st
As shown in the figure, there is a process of sandwiching the rotor pinion 1 using the magnet frames 3 and 4 without applying an overload to the rotor magnet 2, or a process of gluing the rotor magnet directly to the rotor pinion (not shown), or Magnet frame 1 in advance on rotor kana
In this step, the rotor magnet is pressed in, the rotor magnet is glued to it, and the adhesive is dried.

However, the conventional p-body structure has various drawbacks as described below.

(1) There are many parts that engage the rotor, resulting in high cost.

(z) Since all of the parts constituting the rotor are metal parts, the mass becomes large and a moment of inertia acts, reducing efficiency as a step motor.

(8) Since all of the parts that make up the rotor are in the form of single items, automation in their assembly is complicated.

(4) If an overload is applied to the rotor magnet, there are many causes for a decrease in yield, such as cracks occurring in the sintered magnet or, if adhesive is used, adhesive flowing out.

The present invention was made in order to eliminate the above-mentioned drawbacks of the conventional technology, and it reduces the number of parts, greatly improves workability, facilitates automation of rotor assembly, and provides a watch with uniform quality. The object of the present invention is to provide a rotor structure for a step motor and a method for manufacturing the same.

Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

In Fig. 2, pilot hole 50m and driving hole 5 are prepared in advance.
The rotor stem 10 is driven into the 7-pull rear 30 from which 0A has been pressed out, and the rotor magnet 2 is installed. At this time, the rotor magnet 2 has been magnetized in advance and is temporarily fixed to the rotor stem 1o by the magnetization. .

In the above state, the rotor magnets 2 are simply randomly set on the rotor stem 10, and the phases of the binion portions 40α formed by the molding die and the rotor magnets 2 in the magnetic pole direction are also random. Therefore, it is necessary to install a permanent magnet or an electromagnet for positioning on the platen inside the molding die 5 or immediately before the outside of the molding die 5 to perform phase alignment with the molding die 5. The rotor stem 10 and rotor magnets 2 assembled using a polymeric material are fed into the connected molding machine, and the rotor stem 10 and rotor magnet 2 assembled using a polymer material are molded using a mold W5 to complete the rotor shown in FIG. 2.

The present invention completes the rotor through the above-mentioned series of processes, and as described above, the series of openings according to the present invention:'・1: According to the overnight assembly device and rotor structure, the rotor pinion or rotor stem and the rotor constituting the rotor are Since the magnet is integrally insert-molded with a polymer material, the number of parts is small, the number of man-hours required for assembly is reduced, and workability is significantly improved.Furthermore, the component parts are supplied in a hoop shape as a molding form. This facilitates the automation of the molding process and eliminates the occurrence of abnormalities such as rotor magnet damage and racks, which is effective in improving quality.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of a conventional rotor structure, and FIG. 2 is a sectional view showing an embodiment of the rotor of the present invention. 1... Rotor pinion 2... Rotor magnet 3.4... Magnet frame 10... Rotor stem 30... Hoop Chiaria 30g... Pilot hole 50h...Drilling hole 40...Polymer material 40α...Molding pinion part No. I E No. 2 IM

Claims (1)

[Scope of Claims] (1) A rotor for a step motor for a watch, characterized in that the rotor is formed from a rotor pinion, rotor magnets, etc., and the parts such as the rotor pinion and rotor magnets are integrally constructed using a polymer material. . (2) The rotor of a step motor for a timepiece according to claim 1, wherein the polymer material is a thermoplastic resin such as a hard plastic. (8) A step of assembling the rotor pinion or rotor stem and rotor magnet in a hoop carrier in advance, then a step of applying a magnetic field to the rotor magnet to make the magnetic pole direction of the rotor magnet constant; A method for manufacturing a rotor for a step motor for a watch, which comprises a process of insert molding magnets using a polymeric material.