JPH0425437A - Mold for ultrasonic welding - Google Patents

Abstract

PURPOSE:To prevent the mutual welding of mold members by ultrasonic excitation, and to improve operating efficiency by interposing a resin member between the mutually opposed surfaces of the mold members and at a position, where the normal direction of the opposed surfaces crosses at a right angle with the excitation direction of ultrasonic vibrations. CONSTITUTION:Mold members 21, 22 are moved relatively in the vertical direction and fitted mutually through spacers 23, 24 under the state in which plastic fibers 10, 11 are engaged with groove sections 21a, 22a, and the plastic fibers 10, 11 are abutted and held at specified positions. When the mold members 21, 22 are fitted at that time, resin members 30 are interposed among the areas 21b, 22c of lower and upper mold members 21, 22, and relative positional displacement in the horizontal direction of both mold members 21, 22 is prevented while the mutual welding of both surfaces 21b, 22c by ultrasonic excitation is obviated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an ultrasonic welding mold that abuts and holds an optical fiber at a predetermined position when manufacturing an optical branching coupler using an ultrasonic welding method.

(Prior Art) Ultrasonic welding is one of the methods for manufacturing optical branching couplers. This is a method in which the outer peripheries of a plurality of optical fibers are pressed against each other with a predetermined pressing force over a predetermined length, and then ultrasonic waves are applied to bond each core to each other in the pressed area. Specifically, the optical branching coupler is manufactured as follows.

First, a mold corresponding to the shape of the optical branching coupler to be manufactured is prepared. 4 and 5 are perspective views showing an example of the mold, the former showing the disassembled state and the latter showing the fitted state. This mold 20 includes a lower mold member 2
1, and an upper mold member 22 that is finished in a shape that can fit into the lower mold member 21. Further, a groove 21a extending in the X direction is provided on the upper surface of the lower mold member 21, and a groove 22m extending in the X direction is provided on the lower surface of the upper mold member 22, respectively. In addition, in FIG. 4, 23 and 24 are spacers made of elastic columns such as silicone rubber, and the spacers 23 and 24 are inserted between the lower and upper mold members 21 and 22, respectively, so that the lower and upper mold members Relative tilting of the members 21 and 22 is prevented, as well as displacement of the fibers 10, 11.

Next, as shown in FIG. 4, after placing the plastic fiber 10.11 extending in the X direction at a predetermined position, the plastic fiber 10.11 is engaged with the grooves 21a and 22a while the lower and upper mold members are 21 and 22 relative to each other in the vertical direction, the lower and upper mold members 21
．． 22 are fitted together. As a result, the plastic fibers 10.11 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 2.
2, ultrasonic vibration is applied to the upper mold member 22. As a result, a portion of the core is solid-phase bonded to form an optical branching coupler having a predetermined shape.

Finally, after this optical branching coupler is taken out from the mold 2o, the optical branching and coupling part is molded with resin or the like to reinforce the strength of the branching and coupling part.

(Problems to be Solved by the Invention) By the way, in the mold 20 configured as described above, when the upper mold member 22 and the lower mold member 21 are fitted together, the surface of the upper mold member 22 22c and the surface 21 of the lower mold member 21
b and are mutually opposed. Moreover, as shown in Figure 6,
The surface direction of the surfaces 21b and 22c that are in contact with each other is parallel to the excitation direction of the ultrasonic vibration.
, 22C are substantially perpendicular to the excitation direction. Therefore, if the ultrasonic vibration is applied as described above, a problem arises in that the facing surfaces (surfaces 21b, 22b) vibrate in the excitation direction and weld to each other.

Therefore, in order to solve this problem, the surfaces 21b and/or
Alternatively, a method has been proposed in which a lubricant such as graphite is applied to the surface 22c. However, since it is necessary to apply lubricant every time the optical branching coupler is manufactured, work efficiency decreases.

Moreover, it is difficult to apply lubricant only to a designated part, and if lubricant adheres to the fiber 10.11 and ultrasonic welding is performed as it is, the lubricant may get mixed into the optical branching and coupling part, causing the optical Branch coupler characteristics (branch ratio, insertion loss, etc.)
This will have a serious impact on the

(Purpose of the Invention) This invention was made to solve the above problems, and it is possible to manufacture an optical splitter/coupler with excellent work efficiency without affecting the characteristics of the optical splitter/coupler. The purpose is to provide a mold for ultrasonic welding.

(Means for Achieving the Object) This invention consists of two or more mold members that are finished so that they can be freely fitted into each other, and in a fitted state, the outer peripheries of a plurality of optical fibers are brought into contact over a predetermined length. An ultrasonic welding mold for welding the cores of each optical fiber to each other by transmitting ultrasonic vibration applied to at least one of the mold members to the optical fiber while holding the optical fiber, To achieve the purpose, between the mold members or mutually opposing surfaces,
Moreover, a resin member is inserted in the normal direction of the opposing surfaces or in a position substantially orthogonal to the excitation direction of the ultrasonic vibration.

(Function) According to the present invention, the resin member is interposed between the mold members or between the mutually opposing surfaces, and at a position where the normal direction of the opposing surfaces is substantially orthogonal to the excitation direction of the ultrasonic vibration. inserted,
Welding of the mold members to each other due to ultrasonic vibration is prevented. Therefore, the process of applying a lubricant such as graphite is unnecessary, and work efficiency is improved. Furthermore, there is no possibility that the lubricant will adhere to the optical fiber, and the characteristics of the optical branching coupler can be maintained constant.

(Example) Figs. 1 and 2 are perspective views showing an embodiment of an ultrasonic welding mold according to the present invention, with Fig. 1 showing the disassembled state and Fig. 2 showing the fitted state. It 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 has a fitted shape N!
! In (Fig. 2) the lower and upper mold members 21.2
It is finished so that it can be inserted freely between the two. Note that the other components, namely the lower and upper mold members 21 and 22
, spacers 23 and 24 have the same structure as shown in FIG. 4 (conventional example), so their explanation will be omitted here.

For this reason, the plastic fiber 10. extending in the X direction.
11 in place, the plastic fiber 1
0.11 is engaged with the grooves 21a and 22a, the lower and upper mold members 21 and 22 are moved relative to each other in the vertical direction and fitted into each other through the spacers 23 and 24, and the plastic fiber 10. ．． 11 is held in abutment at a predetermined position. Also, when fitting the mold members 21 and 22,
Alternatively, after the fitting is completed, the resin member 30 is attached to the surfaces 2 of the lower and upper mold members 21 and 22 as shown in FIG.
When inserted between 1b and 22c, relative displacement of both full-form members 21, 22 in the horizontal direction is prevented. at the same time,
Welding of both surfaces 21b and 22c due to ultrasonic vibration is prevented in the following manner.

As mentioned above, if the mold members are in contact with each other and the direction of the facing surfaces is parallel to the excitation direction of the ultrasonic vibration, the mold members will be welded together on the facing surfaces. Resulting in. On the other hand, in the case of resins, when the plane direction of the opposing surfaces is perpendicular to the excitation direction, the resins are welded to each other on the opposing surfaces, but when the plane direction and the excitation direction are parallel, In some cases, welding of the two does not occur. That is, the direction of vibration when performing ultrasonic welding is different between the mold member (metal) and the resin. Further, as shown in FIG. 3, which is a partially enlarged sectional view of the mold 20' in the fitted state, a resin member 30 is interposed between the surface 21b of the lower mold member 21 and the surface 22c of the upper mold member 22. Since it is mounted on both sides 21b.

22c is no longer in direct sliding contact. Therefore, even if ultrasonic vibration is applied to the upper mold member 22 for forming the optical branching coupler while the state shown in FIG. 2 (the fitted state of the mold 20') is maintained, the surface 21b.

Welding of the 22c to each other is prevented. In addition, the mold 21°22
Welding due to ultrasonic vibration does not occur at the joint surface between the resin member 30 and the resin member 30.

In addition, since the resin member 30 is prepared in advance and inserted between the surfaces 21b and 22c of the lower and upper mold members 21 and 22 as described above, the lubricant (
Graphite, etc.) coating process is no longer necessary, improving work efficiency. Furthermore, since no lubricant is used, no lubricant is mixed into the optical branching/coupling portion, and problems such as changes in characteristics and deterioration of the optical branching/coupling device do not occur.

In addition, in the above embodiment, the lower and upper mold members 21.
To prevent relative tilting of 22, spacer 23.2
4 are inserted between the lower and upper mold members 21 and 22, respectively, but these spacers 23 and 24 are not essential components. Here, if the spacers 23 and 24 are not provided, the upper surface of the lower mold member 21 and the upper mold member 22
Although the lower surface of the contact surface is in direct contact with the lower surface of the contact surface, since the normal direction of the contact surface and the excitation direction of the ultrasonic vibration are parallel, welding does not occur on those contact surfaces.

In the above embodiment, in order to prevent welding of the lower and upper mold members 21 and 22 due to ultrasonic vibration, the surfaces 21b and 2
The resin member 30 is interposed between the mold members 2c and 2c, but the point is that the ultrasonic vibration is applied between the mutually opposing surfaces of the lower and upper mold members, and in the normal direction of the opposing surfaces. The resin member may be inserted at a position substantially perpendicular to the direction.

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 (
Alternatively, the lower mold member 21) and the resin member 30 may be brought into close contact with each other in advance mechanically or with an adhesive.

Further, in the above embodiment, the lower and upper mold members 21 and 22 are finished in a shape that allows the mold 20' to fit into each other.
However, the present invention is not limited to this, and the present invention can also be applied to a case where the mold member is comprised of three or more mold members that are finished in a shape that allows them to fit into each other. It goes without saying that you can do it.

(Effects of the Invention) As described above, according to the present invention, between the mutually opposing surfaces of the mold members, the normal direction of the opposing surfaces is approximately orthogonal to the excitation direction of the ultrasonic vibration. By inserting the resin member at the position where the mold members are placed, welding of the mold members to each other due to ultrasonic vibration is prevented. This eliminates the need for the process of applying lubricants such as graphite, improving work efficiency, and eliminating the risk of lubricants adhering to optical fibers, allowing the characteristics of the optical splitter and coupler to remain constant. .

[Brief explanation of the drawing]

1 and 2 are respectively perspective views showing one 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 respectively illustrative of ultrasonic welding. FIG. 6 is a perspective view showing a conventional example of a mold, 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, 0... Resin member

Claims (1)

[Claims] (1) Consisting of two or more mold members finished so as to be able to fit into each other, at least one of the mold members is An ultrasonic welding mold for welding the cores of each optical fiber to each other by transmitting ultrasonic vibration applied to one optical fiber to the optical fiber, wherein the surfaces of the mold members facing each other; An ultrasonic welding mold comprising: a resin member inserted between the resin member and the resin member at a position where the normal direction of the opposing surfaces thereof is substantially orthogonal to the excitation direction of the ultrasonic vibration.