JPH0635192Y2 - Movement fastening structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a part fastening structure for a timepiece movement.

[Prior Art] With the price reduction of watches, not only the digital display timepieces but also the pointer display timepieces have been reduced in the number of components and made plastic. Further, base parts for mounting and storing the components and base parts such as a train wheel bridge are made of plastic. As a conventional fastening structure for fastening the base parts to complete the movement, a screw fastening fixing structure shown in a sectional view in FIG. 5 is generally used.

That is, a boss 22 integrally formed on a base plate 21 made of a plastic material has an engaging portion 23 for engaging a component 30 and a train wheel bridge 27, and the component 30 is attached to the engaging portion 23. After engaging and mounting, the train wheel bridge 27 is laminated to hold the component 30 and the screw 31 is fixed to the insertion hole portion 24 of the boss 22 of the main plate 21 by screwing and fastening the movement. .

Further, as another conventional structure, a snap fit fixing structure is known in which a retaining pin is inserted instead of a screw to fasten the movement. For example, a snap-fit retaining device as disclosed in Japanese Patent Laid-Open No. 53-32266 is an example thereof, and FIG. 6 shows its configuration in a sectional view. Boss 22
The engaging portion 23 for engaging the main plate 21 and the hollow insertion hole 24
A convex portion 26 and an axial split groove (not shown) are formed. After the base plate 21 is fitted into the engaging portion 23 of the boss 22, the retaining pin 32 is inserted into the insertion hole 24 to fix the base plate 21.

As another conventional method, a fastening structure for a movement by caulking, which is shown in a sectional view in FIG. 7, is also known. That is, the boss 22 that is the protruding portion of the base plate 21 made of a plastic material has the engaging portion 23 that engages the component 30. After engaging the component 30 with the engaging portion 23,
This is a structure in which the train wheel bridge 27 is laminated to hold the component 30, and the head of the boss 22 made of plastic is heat-crimped to the crimp shape 25 by heating or the like to fasten the movement.

[Problems to be solved by the device]

In the screw tightening fixing structure shown in FIG. 5, a plurality of metal screws are required, and not only the cost of the screw but also the number of assembling steps such as supply, transportation and screw tightening are required. There were drawbacks in that there was a large variation in the torque, and there were many quality problems due to floating parts and the generation of chips during screw tightening. Further, the snap-fit fixing structure shown in FIG. 6 also requires a metal retaining pin, which increases the cost of parts and assembly, and the boss shape of the base plate has a complicated shape with many irregularities, which not only complicates the plastic molding die. However, there was a drawback that the moldability was hindered. Furthermore, although the number of parts is not increased in the thermal caulking fixing structure shown in Fig. 7, the parts are always lifted by thermal caulking and the fixing force is weak, so it is easy to break the fastening part due to impact or the like. However, there is a drawback that it takes time because of thermal deformation and it hinders rationalization of the assembly process.

An object of the present invention is to provide a structure for securely fastening a movement by a simple method without increasing the number of parts.

[Means for Solving the Problems]

In a structure in which a movement is fastened by a boss that is a protruding portion of a main plate made of a plastic material, an engagement portion that engages a component that constitutes the movement with the boss, a hollow insertion hole portion, and an insertion hole portion The retaining shaft part that is press-fitted to prevent coming off is integrally configured, and parts are destroyed by engaging parts with the engaging part and pressing the retaining shaft part that is the head of the boss. It is characterized in that it is press-fitted into the hollow insertion hole of the boss like a wedge, and the components are fixed by expanding the engaging portion.

Further, in a structure in which a boss, which is a protruding portion of a main plate made of a plastic material, and a movement are fastened by a train wheel bridge made of a plastic material, an engaging portion for engaging a component constituting the movement with the boss of the main plate is provided. , An insertion hole portion having an upper end opened, and an engagement hole portion that engages with an engagement portion of a boss of the main plate in the train wheel bridge, and a retaining portion that is press-fitted into the insertion hole portion and prevents disengagement. Are integrally formed, the parts are engaged with the engaging portions of the boss of the main plate, the engaging hole portions of the train wheel bridge are engaged, and the retaining shaft portion of the train wheel bridge is pressed. As a result, while being partially destroyed, it is press-fitted into the insertion hole of the boss of the main plate in a wedge shape, and by expanding the engaging portion, the parts are fixed and the train wheel bridge is fixed. Characterized by being configured.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view showing a first embodiment of the present invention.
FIG. 2 is a sectional view showing the movement fastening state of the first embodiment of the present invention. According to FIG. 1, an engaging portion 3 for engaging a component 10 and a train wheel bridge 7 and a hollow insertion hole portion 4 are provided on a boss 2 projecting from a main plate 1 made of a plastic material.
A retaining shaft portion 5 that is press-fitted into the insertion hole portion 4 and prevents the detachment is integrally formed via a cutting portion 6. The shaft diameter of the retaining shaft portion 5 is set larger than the hole diameter of the insertion hole portion 4 so that the retaining shaft portion 5 is press-fitted into the insertion hole portion 4. Further, the cutting portion 6 has the retaining shaft portion 5 and the insertion hole portion 4
The wall thickness is set so that it will be cut with a force that is less than the force to press into.

A plurality of bosses of the main plate 1 are prepared in accordance with the respective parts 10, and the parts 10 are engaged with the engaging parts 3 to be housed, and then the train wheel bridge 7 is laminated to form the entire movement. Thereafter, the retaining shaft portion 5 protruding from the head of the boss 2 is strongly pressed toward the main plate 1 to cut the thin cut portion 6, and the retaining shaft portion 5 is inserted into the insertion hole portion 4. A shaft portion 5a press-fitted in a wedge shape is formed, and as shown in FIG. 2, the shaft portion 5a spreads the insertion hole portion 4 and the engagement portion 3 of the boss 2 and spreads the components 10 engaged. The parts 10 and the train wheel bridge 7 are fixed by being pressed against the train wheel bridge 7 and the movement is fastened. Also, the main plate 1 without the train wheel bridge 7
Even in the configuration of only the component 10 and the component 10, it is possible to fasten the main plate 1 and the component 10 as described above by the fixing structure of the present invention.

FIG. 3 is a sectional view showing a second embodiment of the present invention. Further, FIG. 4 is a sectional view showing the movement fastening state of the second embodiment of the present invention. According to FIG. 3, the boss 12 projecting from the base plate 11 made of a plastic material is provided with an engaging portion 13 for engaging the component 20 and the train wheel bridge 17, and a hollow insertion hole portion 14. Reference numeral 17 designates a train wheel bridge made of a plastic material, which is press-fitted into the insertion hole portion 14 of the boss 12 of the main plate 11 through a thin-walled cut portion 19 to integrally form a retaining shaft portion 18 for preventing the retaining shaft. . The shaft diameter of the retaining shaft portion 18 is the boss 12 of the main plate 11.
It is made thicker than the hole diameter of the insertion hole 14
18 is set so that it can be press-fitted into the insertion hole portion 14. Further, the thickness of the cutting portion 19 is set so that the retaining shaft portion 18 can be cut with a force less than the force of press-fitting it into the insertion hole portion 14.

A plurality of bosses 12 of the main plate 11 are prepared in accordance with the respective components 20, and the components 20 are engaged with the engaging portions 13 of the bosses 12 to be housed therein, and then the wheel train bridge 17 is laminated to form the entire movement. Make up. After that, the head portion of the retaining shaft portion 18 that is integrally formed with the train wheel bridge 17 is strongly pressed toward the main plate 11 to cut the thin cut portion 19, and the retaining shaft portion 18 is inserted. A shaft portion 18a press-fitted in a wedge shape is formed in the hole portion 14, and the retaining shaft portion 18a is engaged by pushing the engagement portion 13 of the boss 12 of the main plate 11 as shown in FIG. parts
20 and the train wheel bridge 17 are fixed to the main plate 11 to fasten the movement.

[Effect of device]

As is clear from the above description, according to the present invention, not only the movement can be fastened without increasing the number of parts, but also the main plate and the wheel bridge are integrally formed with the retaining shaft, which is called alignment or transportation. The equipment on the assembly process is also insoluble and the assembly process can be simplified. Further, since the fixing is performed by press fitting, the assembling speed can be increased, there is no quality trouble such as defective conduction due to floating of parts, and there is an effect that it is strong against impact.

[Brief description of drawings]

1 is a sectional view showing a fastening structure of a movement according to a first embodiment of the present invention, FIG. 2 is a sectional view showing a fastening state of a movement according to a first embodiment of the present invention, and FIG. 3 is a second view of the present invention. FIG. 4 is a cross-sectional view showing an embodiment, FIG. 4 is a cross-sectional view showing a movement fastening state of a second embodiment of the present invention, FIG. 5 is a cross-sectional view showing a conventional screw fastening fixing structure, and FIG. 6 is a conventional snap. Sectional drawing which shows a fitting fixing structure, FIG. 7 is sectional drawing which shows the conventional thermal caulking fixing structure. 1, 11 ...... Base plate, 2, 12 ...... Boss, 3, 13 ...... Engagement part, 4, 14 ...... Insertion hole part, 5, 5a, 18, 18a ...... Retaining shaft part, 6, 19 ... … Cutting part, 7, 17 …… Train wheel bridge, 10, 20 …… Parts.

Claims (2)

[Scope of utility model registration request] 1. A structure in which a movement is fastened by a boss that is a protruding portion of a substrate made of a plastic material,
The boss is integrally formed with an engagement portion that engages a component that constitutes a movement, a hollow insertion hole portion, and a retaining shaft portion that is press-fitted into the insertion hole portion and prevents the detachment. By engaging a part with the engaging part and pressing the retaining shaft part that is the head of the boss, a part of it is destroyed, and it is press-fitted into the hollow insertion hole of the boss in a wedge shape, A movement fastening structure, characterized in that the components are fixed by expanding the engaging portion. 2. In a structure in which a movement is fastened by a boss that is a projecting portion of a substrate made of a plastic material and an auxiliary substrate made of a plastic material, the boss of the substrate is engaged with a component constituting the movement. Department,
An insertion hole portion having an open upper end is formed, and an engagement hole portion that engages with an engagement portion of a boss of the substrate and a retaining portion that is press-fitted into the insertion hole portion and prevents the detachment are formed on the auxiliary substrate. It is configured integrally, by engaging a part with the engaging portion of the boss of the substrate, engaging the engaging hole portion of the auxiliary substrate, and pressing the retaining shaft of the auxiliary substrate. While being partially destroyed, it is press-fitted into the insertion hole of the boss of the board in a wedge shape, and the engaging part is expanded to fix the parts and the auxiliary board. A characteristic movement fastening structure.