JPH059148Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The invention is designed to sandwich another member, such as an ink absorber, between two ultrasonically welded members, such as the front and rear shafts of a writing instrument, without play. This invention relates to an ultrasonic welded structure.

(Prior art) Conventionally, as shown in FIG. 18, the joint surfaces 20a and 21a of the front shaft 20 and rear shaft 21 made of synthetic resin are integrated without any gaps by ultrasonic welding, and polyester fibers and acrylic fibers are arranged inside. The tip of the ink storage body 22 made of a fiber bundle such as
b to press against the tapered inner surface 20b of the nib 20 and hold it without any play, and place the rear part of the nib 23 on the ink storage body 2.
A writing instrument that can be inserted into a pen is known.

(Problem to be solved by the invention) In the above-mentioned conventional technology, since the tip of the ink storage body is compressed in the radial direction of pressing into a tapered surface to prevent backlash, the capillary action of the ink storage body is inhibited. There was a problem.

(Means for Solving the Problems) The present invention aims to solve the above-mentioned problems by bringing two members into contact with each other with a gap in between, placing another member in the gap, and sandwiching the two members between the two members. In such a synthetic resin structure, a protrusion that can be welded by ultrasonic vibration is provided on the abutment surfaces of the two members, and the protrusion is completely welded to the clamping surface of the other member, so that the abutment surface The invention is characterized in that a thermally deformable protrusion is provided which can be heated by ultrasonic vibration at a height such that when there is no gap, the protrusion is pressurized and deformed by heat and no rattling occurs.

Figure 1 is an explanatory diagram of the action of ultrasonic welding. When welding synthetic resin members A and B together, a protrusion a is provided on the joint surface of one member A, and the protrusion a is attached to member B.
When the ultrasonic horn H is brought into contact with the member A,
The vibration energy of the ultrasonic horn H concentrates on the protrusion a, melting and welding the protrusion a.

By the way, as shown in Fig. 2, members A and B are ultrasonically welded, and another member C is inserted into the gap formed by members A and B.
When forming an ultrasonic welded structure that sandwiches parts A and B, if part C is short, looseness will occur as shown in Figure 3, and if part C is too long, a gap will be created between the welded parts of parts A and B as shown in Figure 4. This results in insufficient welding.

When there is a member C sandwiched between member A and member B, the present invention not only uses ultrasonic welding of member A and member B, but also uses the relative dimensional variation of members A, B, and C to In order to eliminate backlash and insufficient welding of parts A and B, as shown in Fig. 5, heat deformation protrusions _a3 are formed on parts A and C to cover the dimensional variations.
It is provided protruding from the clamping surface.

When protrusions a ₁ and a ₂ of members A and B are completely welded as shown in Fig. 6, thermally deformed protrusion a ₃ is attached to member C as shown in Fig. 7.
The height is such that the tip is pressed and deformed by the heat when it comes into contact with the handle, and can be held without play.

Members A, B, and C may be combined as shown in Fig. 8, two sandwiching members C and C' may be arranged in parallel as shown in Fig. 9, and members C and C' may be combined as shown in Fig. 10. They may be arranged in series, or the member C may be a ring as shown in FIG.

(Embodiment) Fig. 12 shows the first embodiment of the present invention, in which 1 is a front shaft made of synthetic resin, 2 is a rear shaft made of synthetic resin, 3 is an ink tank, 4 is a bellows made of thermosetting resin, 5 is a pen tip. A protrusion 1a that is welded by the above-mentioned ultrasonic welding is protrudingly provided on the contact surface of the front shaft 1 with the rear shaft 2,
Completely welded without any gaps by ultrasonic vibration.
1b is a thermally deformable protrusion that is pressed and deformed at the tip of the bellows 4 without melting, and the bellows 4 and the ink tank 3 are held together without play.

FIG. 13 shows a second embodiment of the present invention, in which 11 is a front shaft made of synthetic resin, 12 is a rear shaft made of synthetic resin, 13 is an ink storage body, and 14 is a pen tip. On the front shaft 11, a projection 11a is formed on the surface in contact with the rear shaft 12, and a thermally deformable projection 11b is formed on the surface in contact with the ink storage body 13. Before ultrasonic welding, it looks as shown in Fig. 14, but when the ultrasonic horn is applied, the protrusion 11a
are completely welded without any gaps. At this time, the thermally deformable protrusion 11b is also heated, and the top part is pressed and deformed by the ink storage body 13, so that the ink storage body 13 is held without play (see FIG. 15).

Figures 16 and 17 show the third embodiment of the present invention,
Contact surface 3 of the synthetic resin frame 30 with the synthetic resin frame 31
A protrusion 30c to be ultrasonically welded is formed on the contact surface 30a with 1a. Reference numeral 33 denotes a resin lens, and a thermally deformable protrusion 30b is formed on the surface of the synthetic resin frame 30 that comes into contact with the resin lens 33.
That is, the resin lens 33 is held between the heat deformable protrusion 30b of the synthetic resin frame 30 and the rib 31b of the synthetic resin frame 31 without play.

Note that the present invention can be applied not only to the above-mentioned writing instruments and lenses but also to various other products.

(Effects) According to the present invention, in a synthetic resin structure in which two members are brought into contact with each other with a gap, another member is disposed in the gap, and the two members are sandwiched between the two members.
A protrusion that can be welded by ultrasonic vibration is provided on the abutment surface of a member, and when the protrusion is completely welded to the clamping surface of another member and there is no gap between the abutment surfaces, the abutment surface is pressed and deformed by heat. Since there is a protruding heat deformation protrusion that can be heated by ultrasonic vibration at a height that does not cause rattling, parts A and B are ultrasonically welded and the gap formed by parts A and B is filled with other parts. When forming an ultrasonic welding structure that sandwiches member C, member C due to relative dimensional variations of members A, B, and C.
It is possible to eliminate backlash and insufficient welding of members A and B.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the action of ultrasonic welding, Fig. 2 is a front view of an embodiment of a structure to which the present invention is applied, Fig. 3 is a front view when member C in Fig. 2 is short, and Fig. 4 is a front view of an embodiment of the structure to which the present invention is applied. Fig. 2 is a front view when member C is too long; Fig. 5 is a front view before ultrasonic welding showing the principle of the present invention; Fig. 6 is a front view of Fig. 5 after ultrasonic welding; 7 is an enlarged view of the main part of FIG. 6, FIGS. 8 to 11 are front views of various embodiments of the structure to which the present invention is applied, FIG. 12 is a front sectional view of the first embodiment of the present invention, and FIG. The figure is a front sectional view of the second embodiment of the present invention, FIG. 14 is a front sectional view of the main part before ultrasonic welding of FIG. 13, and FIG. 15 is a front sectional view of the main part of FIG. 13 after ultrasonic welding. , FIG. 16 is a plan view of a third embodiment of the present invention, FIG. 17 is a front sectional view taken along the line AA in FIG. 16, and FIG. 18 is a front sectional view of a conventional comparative example. A, B... Members to be ultrasonically welded with a gap, C... members disposed and sandwiched between the gaps of members A and B, a ₁ , a ₂ ... members protruding from the joint surface of member A. Protrusion provided, a ₃ ... Heat deformation protrusion provided protruding from the member C clamping surface of member A, 1, 11 ... front shaft, 2, 12 ... rear shaft,
1a, 11a, 30c... Protrusions to be ultrasonically welded, 1b, 11b, 30b... Heat deformed protrusions heated by ultrasonic vibration.

Claims (1)

[Scope of utility model claims] In a synthetic resin structure in which two members are in contact with each other with a gap between them, another member is disposed in the gap, and the two members are sandwiched, ultrasonic vibration is applied to the contact surfaces of the two members. A protrusion that can be welded is provided protrudingly, and the height is such that when the protrusion is completely welded to the clamping surface of another member and there is no gap on the contact surface, the height will not be pressed and deformed by heat and cause play. An ultrasonic welded structure with protruding thermally deformable protrusions that can be heated by ultrasonic vibrations.