JPH0564842A - Ultrasonic fusing method and jig for ultrasonic fusion - Google Patents

Abstract

PURPOSE:To provide such a method and jig that neither a crack nor a flaw is generated in a fragile part of such a work wherein an opening part or a notch is in the vicinity of a fusing part. CONSTITUTION:At the time of performance of ultrasonic fusing, projected parts 6a of a jig main body 6 for ultrasonic fusion comprised of room temperature vulcanizing type silicone resin are fitted respectively into, for example, key holes 5 each of a key lid 2 of a telephone and fused. Ultrasonic vibration energy to a fragile part 2c of a molded product close to the key holes 5 each is weakened by a vibration attenuation action by the projected part 6a and neither a crack nor a flaw is generated in the fragile part 2c of the molded product.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic welding method and an ultrasonic welding jig applied when assembling, for example, a plastic molded product, and particularly to a part to be welded (hereinafter referred to as a work piece). The present invention relates to an ultrasonic welding method in the case where there is a notch or an opening in the call) and an ultrasonic welding jig to be used at that time.

[0002]

2. Description of the Related Art For example, a viscoelastic body such as plastic has a characteristic that vibration energy due to ultrasonic vibration is converted into heat energy in the plastic to generate heat.
There is known a so-called ultrasonic welding method in which plastics are melted and joined by utilizing this heat generation.

This welding method is simpler than the conventional method of joining plastics with each other by means of inclusions such as an adhesive, and the reason is that the welding procedure is simple and the appearance finish after welding is beautiful. In recent years, it has been used in various production fields.

[0004]

In the ultrasonic welding as described above, for example, a portion of a work to be welded (hereinafter, referred to as a welded work) is a work to be welded (hereinafter, referred to as a welded work). The welded part heats and melts by contacting the part to be welded), abutting a vibrator (also called a horn) on it, and concentrating ultrasonic energy from the horn to the welded part. Workpieces are joined.

However, there is no problem if the ultrasonic energy propagates only to the portion of the work to be welded in this way, but not only the welded portion, depending on the structure (wall thickness) and shape of the welded work or the work to be welded. The vibration energy may propagate to other parts that do not require welding, which may have various adverse effects.

For example, specifically, in the vicinity of one welded portion,
There are notches and holes between the two welded parts.
In the case of a thin work having a fragile portion, there is a problem that vibration from the welded portion resonates largely in the vicinity of the notch or the hole and cracks or scratches are generated in the fragile portion.

The present invention is provided in view of the problems of the ultrasonic welding method described above. Even when welding a work having a fragile portion, the welding does not cause cracks or scratches in the fragile portion. An object of the present invention is to provide a jig used for the method and its welding.

[0008]

According to the present invention, in order to achieve the above-mentioned object, in the vicinity of the welding site of the welding work to be ultrasonically welded to the work to be welded, or between the welding sites, Is a method for ultrasonically welding a welded work having a notch or an opening that is weaker than the work part, and the ultrasonic cutoff material is applied to the notch or the opening during ultrasonic welding. There is provided an ultrasonic welding method, characterized in that ultrasonic vibration energy is applied to a welding portion while engaging a supporting member made of the same.

Further, according to the present invention, there is provided an ultrasonic welding jig used when ultrasonically welding a welded work having a notch or an opening in the vicinity of a welded portion, which is an ultrasonic attenuation material. And a jig body capable of supporting the welded work, the jig body further having a protrusion capable of engaging with the notch or the opening and supporting the periphery thereof. A sonic welding jig is provided.

[0010]

[Action] A support member made of an ultrasonic attenuating material is engaged with a notch or an opening in the vicinity of a fragile portion of a welded work to support the same, so that the vibrator of the ultrasonic welding machine can face the fragile portion. The ultrasonic vibration energy is absorbed by this support member and is not attenuated by the time it reaches the fragile portion to cause it to resonate significantly.

[0011]

Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows, as an example of a work that can be welded by the method of the present invention, a state before assembling an upper lid portion of a telephone, and an ultrasonic welding jig used in this assembly (ultrasonic welding). Is shown. In this figure, 1
Is an upper lid body as a work to be welded, 2 is an upper lid body 1
Key lid as a welding work for ultrasonically welding to 3
Is an ultrasonic welding jig (hereinafter referred to as a jig) as a supporting member for supporting the upper lid body 1 and the key lid 2 on the welding.
The upper lid body 1 and the key lid 2 are both thermoplastic plastic molded products.

The upper lid main body 1 has a key lid opening 4 for mounting the key lid 2 on the top thereof, and the side edge portions 2a and 2b of the key lid 2 are received on both side edges thereof. Welding projections 1a and 1b are provided. The two parts are assembled by welding the side edge portions 2a and 2b of the key lid 2 to the welding projections 1a and 1b of the upper lid body 1, respectively.

When the telephone is completed, the key cover 2 is provided with a plurality of key holes 5 in three rows, into which a plurality of keys (not shown) are inserted, and therefore, between the adjacent key holes 5. The lattice-shaped molded product portion, particularly the molded product portion 2c that separates the upper and lower key holes 5 in the central row, is relatively weak compared to other portions.

The jig 3 is a resin (thermoplastic resin) that solidifies by cooling, such as PVC sol (vinyl chloride resin) or RTV silicone (normal temperature vulcanizing silicone resin), or a resin that solidifies by heating (thermosetting). Resin body) and a metal receiving member (also called an anvil) 7 attached to the side surface of the jig body 6.

The jig body 6 has elasticity like rubber due to its material, and has an outer shape that fits tightly to the upper lid body 1. Further, on the upper surface thereof, a plurality of projecting portions 6a having substantially the same shape are provided corresponding to each key hole 5 of the key lid 2, and the upper lid main body 1 provided with the key lid 2 is attached to the jig 3.
When mounted on the key holes 5, the protrusions 6a are closely fitted in the key holes 5.

FIG. 2 shows the upper lid body 1 and the key lid 2 described above.
In ultrasonic welding, first, the key lid 2 is attached to the opening portion 4 of the upper lid main body 1, and further this is attached to the jig 3, and FIG. It is sectional drawing which follows A.

As is clear from these figures, in the preparation stage for ultrasonic welding, the upper lid body 1 as the work to be welded is laterally supported by the receiving member 7 on the side of the jig.
Further, the key lid 2 is placed on the upper lid body 1, and each key hole 5
The projecting portion 6a of the jig main body 6 having elasticity is engaged with.

Therefore, the welding of these plastic molded products is performed with respect to the side edge portions 2a, 2b of the key lid 2 located on the welding projections 1a, 1b of the upper lid body 1 in the assembled state as shown in the figure. This is done by abutting a horn (not shown) of the ultrasonic welding machine from above and operating it. At this time, the upper lid main body 1 itself is received from below by a receiving member 7 provided on the side of the jig. In order to be supported, the ultrasonic vibration energy from the horn is a plastic molded product of the upper lid body 1 and the key lid 2.
Is propagated to and the two contact portions, that is, the welding projections 1a and 1b, are converted by the conversion of vibration energy into heat energy.
And the edge portions 2a and 2b are melted, whereby the upper lid body 1 and the key lid 2 are joined.

At this time, the ultrasonic vibration from the horn is not only applied to the contact portion of the two parts but also to the other edge portions 2a, 2b side through the rib between the key holes 5, as shown by the arrow in FIG. It is propagated and its vibration is conventionally two edge parts 2
In the intermediate molded product portion 2c between a and 2b, it can be maximized due to the resonance action, but according to the present embodiment, since each key hole 5 is filled with the projecting portion 6a of the elastic jig body 6, The ultrasonic vibration energy from the horn is weakened by the vibration damping action of the protrusion 6a itself in the process of being transmitted to the molded product part 2c, and as a result, the molded product part 2c is obtained.
The adverse effect on c, that is, the generation of cracks and scratches that have conventionally occurred can be prevented.

As described above, according to this embodiment, the ultrasonic attenuating material is provided with the protrusions 6a which engage with the key holes 5 forming the fragile molded product portion 2c in the key lid 2 without excess or deficiency. Welding is performed by using the jig 3 consisting of the above-mentioned, so that the propagation of ultrasonic vibration energy to the fragile site is weakened as compared with the conventional welding method in which only the receiving member 7 without the jig as shown in FIG. 4 is supported. Therefore, even if the oscillator oscillation time is made longer than in the conventional case, the welding strength can be increased without causing cracks or scratches in the fragile portion.

The above-mentioned embodiment has been a description of a welding jig and a welding method applied to a work forming a fragile portion in the middle of two welding portions, but the present invention is naturally limited to this embodiment. Even if there is a notch near the welded part, a jig made of ultrasonic attenuating material with a protrusion that complements the notch shape is prepared. It should be welded while backing up.

[0022]

As described above, according to the present invention, when the work is ultrasonically welded, a notch or an opening near the fragile portion of the work is engaged with a supporting member made of an ultrasonic attenuation material to support the work. However, by ultrasonically oscillating, the ultrasonic vibration energy from the oscillator of the ultrasonic waves to the fragile portion is absorbed by the support member, and the generation of cracks or scratches in the fragile portion is prevented. Further, along with this, the ultrasonic oscillation time can be increased, and the welding strength of the work site to be welded can be increased.

[Brief description of drawings]

FIG. 1 is an external perspective view of a portable telephone component and a welding jig to which an ultrasonic welding method according to the present invention can be applied.

FIG. 2 is a top view in which the respective elements shown in FIG. 1 are integrated in ultrasonic welding.

FIG. 3 is a sectional view of the component and the jig taken along the line AA of FIG.

FIG. 4 is a cross-sectional view of components and jigs during conventional welding corresponding to FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Upper lid main body (welding work) 1a, 1b ... Welding projection (welding site) 2 ... Key lid (welding work) 2a, 2b ... Side edge part (welding site) 2c ... Molded product part (fragile part) 3 ... jig for ultrasonic welding (support member) 5 ... key hole (opening) 6 ... jig body 6a ... protruding portion

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ichisuke Kuramochi 654 Kawawa-cho, Midori-ku, Yokohama-shi, Kanagawa Within Fujitsu Kasei Co., Ltd.

Claims (2)

[Claims] 1. A notch or an opening for providing a weaker portion than other work portions in the vicinity of the welded portion of the work to be ultrasonically welded to the work to be welded or between the welded portions. A method for ultrasonically welding a welded work having a portion, wherein ultrasonic vibration energy is applied to the welded portion while engaging a supporting member made of an ultrasonic attenuating material with the notch or opening during ultrasonic welding. An ultrasonic welding method characterized by giving. 2. An ultrasonic welding jig used when ultrasonically welding a welding work having a notch or an opening in the vicinity of a welding portion, the welding work comprising an ultrasonic attenuation material. A jig for ultrasonic welding, characterized in that it has a jig body capable of supporting the above, and the jig body further has a protrusion capable of engaging with the notch or the opening and supporting the periphery thereof. ..