JPH074860B2 - Ultrasonic welding mold - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an ultrasonic welding mold for abutting and holding an optical fiber at a predetermined position when manufacturing an optical branching / coupling device by an ultrasonic welding method.

(Prior Art) One of the methods for manufacturing an optical branching / coupling device is an ultrasonic welding method. This is a method in which the outer peripheral portions of a plurality of optical fibers are pressed against each other with a predetermined pressing force over a predetermined length, ultrasonically excited, and the cores are bonded to each other in the pressed region. Specifically, the optical branching / coupling device is manufactured as follows.

First, a mold corresponding to the shape of the optical branching / coupling device to be manufactured is prepared. 4 and 5 are perspective views showing an example of a mold, the former showing a disassembled state and the latter showing a fitted state. This mold 20 has a lower mold member 21.
And an upper mold member 22 finished to a shape that can be fitted to the lower mold member 21. Further, a groove portion 21a extending in the X direction is provided on the upper surface of the lower mold member 21, and a groove portion 22a extending in the X direction is provided on the lower surface of the upper mold member 22, respectively. In FIG. 4, 23 and 24 are spacers made of an elastic material such as silicon rubber. The spacers 23 and 24 are inserted between the lower and upper mold members 21 and 22, respectively, and the lower and upper mold members are inserted. The relative inclination of 21, 22 is prevented, and the displacement of the fibers 10, 11 is also prevented.

Next, as shown in FIG. 4, after the plastic fibers 10 and 11 extending in the X direction are arranged at predetermined positions, the lower and upper mold members are engaged while the plastic fibers 10 and 11 are engaged with the grooves 21a and 22a. The lower and upper mold members 21, 22 are fitted to each other by relatively moving 21, 22 in the vertical direction. As a result, the plastic fibers 10 and 11 are held in contact with each other at a predetermined position (Fig. 5), and preparation for ultrasonic welding is completed.

Subsequently, a predetermined pressing force is applied from above to the upper mold member 22.
The ultrasonic vibration is applied to the upper mold member 22 while still being applied to the upper mold member 22. As a result, a part of the core is solid-phase bonded,
An optical branching / coupling device having a predetermined shape is formed.

Finally, after taking out this optical branching coupler from the mold 20,
The optical branch coupling portion is molded with resin or the like to reinforce the strength of the branch coupling portion.

(Problems to be Solved by the Invention) In the die 20 configured as described above, when the upper die member 22 and the lower die member 21 are fitted, the surface 22c of the upper die member 22 is formed. And the surface 21b of the lower mold member 21 are in contact with each other. Moreover, as shown in FIG. 6, surfaces that are in contact with each other
The surface directions of 21b and 22c are parallel to the excitation direction of the ultrasonic vibration, in other words, the normal direction of the surfaces 21b and 22c is substantially orthogonal to the excitation direction. Therefore, when ultrasonic vibration is applied as described above, there arises a problem that the contact surfaces (surfaces 21b and 22b) vibrate in the vibration direction and are welded to each other.

Therefore, in order to solve this problem, a means of applying a lubricant such as graphite to the surface 21b and / or the surface 22c has been proposed. However, since it is necessary to apply a lubricant each time the optical branching / coupling device is manufactured, work efficiency is reduced.

Moreover, it is difficult to apply the lubricant only to the predetermined part, and if the lubricant adheres to the fibers 10 and 11 and the ultrasonic welding is performed as it is, the lubricant is mixed in the optical branching coupling part and the optical branching is performed. This will seriously affect the characteristics of the coupler (branch ratio, insertion loss, etc.).

(Object of the Invention) The present invention has been made to solve the above problems, and an optical branching / coupling device can be manufactured without affecting the characteristics of the optical branching / coupling device and with excellent work efficiency. An object is to provide a mold for ultrasonic welding.

(Means for Achieving the Object) The present invention is composed of two or more mold members finished so that they can be fitted to each other, and abutting the outer peripheral portions of a plurality of optical fibers over a predetermined length in a fitted state. An ultrasonic welding mold for transmitting ultrasonic vibrations applied to at least one of the mold members to the optical fibers while holding the core members to weld the cores of the optical fibers to each other, In order to achieve the object, between the surfaces of the mold members facing each other,
Moreover, the resin member is provided so that the normal line direction of the facing surface is substantially orthogonal to the exciting direction of the ultrasonic vibration.

(Operation) According to the present invention, the resin member is interposed between the surfaces of the mold members facing each other, and at a position where the normal direction of the facing surfaces is substantially orthogonal to the exciting direction of the ultrasonic vibration. Inserted,
Welding of the mold members by ultrasonic vibration is prevented. Therefore, the step of applying a lubricant such as graphite becomes unnecessary, and the work efficiency is improved. Moreover, there is no possibility that the lubricant will adhere to the optical fiber, and the characteristics of the optical branching / coupling device can be kept constant.

(Embodiment) FIGS. 1 and 2 are perspective views showing an embodiment of an ultrasonic welding mold according to the present invention. FIG. 1 shows a disassembled state and FIG. 2 shows a fitted state. Shows. As shown in FIG. 1, this ultrasonic welding mold 20 'is composed of lower and upper mold members 21,22, spacers 23,24, and a resin member 30. The resin member 30 is finished so that it can be inserted between the lower and upper mold members 21 and 22 in the fitted state (FIG. 2). The other components, that is, the lower and upper mold members 21 and 22, and the spacers 23 and 24 have the same configurations as those shown in FIG. 4 (conventional example), and therefore the description thereof is omitted here.

For this reason, the plastic fibers 10, 11 extending in the X direction
The plastic fiber 10, 11
With the groove portions 21a and 22a engaged, the lower and upper mold members 21 and 22 are relatively moved in the vertical direction to move the spacer 2
When mated together via 3,24, plastic fiber
10, 11 are held in contact with each other at a predetermined position. Also, the mold member 21,
Resin material when mating 22 or after mating
30 to the lower and upper mold members 21, 2 as shown in FIG.
By inserting it between the second surfaces 21b and 22c, relative displacement of both mold members 21 and 22 in the horizontal direction is prevented. At the same time, welding of both surfaces 21b and 22c due to ultrasonic vibration is prevented as follows.

As described above, when the mold members are in contact with each other and the surface direction of the contact surface is parallel to the vibration direction of the ultrasonic vibration, the mold members are welded at the contact surface. Resulting in. On the other hand, in the case of resins, when the surface direction of the contact surface is orthogonal to the vibration direction, the resin is welded on the contact surface, but the surface direction and the vibration direction are parallel. In some cases, welding of both does not occur. That is, the mold member (metal) and the resin have different vibration directions when ultrasonically welding. Further, as shown in FIG. 3 which is a partially enlarged sectional view of the fitted state of the die 20 ′, the resin member 30 is interposed between the surface 21 b of the lower die member 21 and the surface 22 c of the upper die member 22. Since it is mounted, both surfaces 21b and 22c do not come into direct sliding contact. Therefore, even if ultrasonic vibration is applied to the upper mold member 22 to form the optical branching coupler in the state shown in FIG. 2 (fitting state of the mold 20 '), the surface 21b, Welding of 22c is prevented. It should be noted that welding at the joint surface between the molds 21 and 22 and the resin member 30 due to ultrasonic vibration does not occur.

Further, as described above, the resin member 30 is prepared in advance and is inserted between the surfaces 21b, 22c of the lower and upper mold members 21, 22, so that the lubricant (graphite or the like shown in the proposed example is used. The coating step of) becomes unnecessary and the working efficiency is improved. Moreover, since no lubricant is used, the lubricant is not mixed into the optical branching coupling portion, and there is no problem of change or deterioration of the characteristics of the optical branching coupler.

Incidentally, in the above embodiment, the lower and upper mold members 21, 22
The spacers 23 and 24 are inserted between the lower and upper mold members 21 and 22 respectively to prevent the relative inclination of the spacers 23 and 24, but these spacers 23 and 24 are not essential components. Here, when the spacers 23, 24 are not provided, the upper surface of the lower mold member 21 and the lower surface of the upper mold member 22 are in direct contact, but the normal direction of the contact surface and the ultrasonic vibration Since the direction of vibration is parallel, welding does not occur at their contact surfaces.

In the above embodiment, in order to prevent welding of the lower and upper mold members 21 and 22 by ultrasonic vibration, the resin member 30 is interposed between the surfaces 21b and 22c. The resin member may be inserted between the surfaces of the upper mold member that correspond to each other, and at a position where the normal line direction of the opposing surfaces is substantially orthogonal to the vibration direction of the ultrasonic vibration.

Further, in the above embodiment, the mold members 21 and 22 and the resin member 30 are separated from each other, but the upper mold member 22 (or the lower mold member 21) and the resin member 30 are mechanically or It may be adhered in advance by an adhesive or the like.

Further, in the above embodiment, the mold 20 'is composed of the lower and upper mold members 21 and 22 which are finished in a shape that can be fitted to each other. It goes without saying that the present invention can also be applied to a case where the present invention can be applied to a case where it is composed of three or more mold members finished in a shape that can be fitted.

(Effect of the Invention) As described above, according to the present invention, between the surfaces of the mold members facing each other, and the normal direction of the facing surfaces is substantially orthogonal to the exciting direction of the ultrasonic vibration. By interposing the resin member at the position to be welded, welding of the mold members due to ultrasonic vibration is prevented. Therefore, the step of applying a lubricant such as graphite becomes unnecessary, the working efficiency can be improved, and the possibility that the lubricant adheres to the optical fiber is eliminated, and the characteristics of the optical branching coupler can be kept constant. .

[Brief description of drawings]

1 and 2 are perspective views showing an embodiment of an ultrasonic welding mold according to the present invention, FIG. 3 is a partially enlarged sectional view thereof, and FIGS. 4 and 5 are ultrasonic welding. FIG. 6 is a perspective view showing a conventional example of a molding die, and FIG. 6 is a partially enlarged sectional view thereof. 10, 11 ... Plastic fiber, 21 ... Lower mold member, 21b
... surface, 22 ... upper mold member, 22c ... surface, 30 ... resin member

Claims (1)

[Claims] 1. A mold comprising at least two mold members finished so that they can be fitted with each other, and at least while holding the outer peripheral portions of a plurality of optical fibers in contact with each other over a predetermined length in a fitted state. An ultrasonic welding mold for transmitting ultrasonic vibration applied to one of the members to the optical fiber to weld the cores of the optical fibers to each other, wherein the mold members face each other. Ultrasonic welding mold, characterized by comprising a resin member interposed between the surfaces to be formed, and at a position in which the normal line direction of the opposite surface is substantially orthogonal to the exciting direction of the ultrasonic vibration. .