JPH10291255A - Magnetic induction welding method for large-scale synthetic resin member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the transmitting condition of heat from a metallic wire in magnetic induction welding to secure fusion over the whole welded portion to thereby eliminate a local jointing failure and water entering the welded portion due to the joint failure, whereby a risk of an internal heating heater being damaged, leak and electric shock can be avoided and generation of rust on the metallic wires and breakage of the welded portion due to rust so generated can also be eliminated. SOLUTION: A groove 5 is formed in a confronting surface of either a welded portion on a main body 1 side of a toilet seat or a welded portion of a bottom plate 2 side thereof in a loop fashion so as to go therearound in welded portions 3, 4 on inner and outer circumferential edges of the main body 1 and the bottom plate 2 of the toilet seat of a western style toilet which are large scale synthetic resin members that are to be welded together, and a metallic wire 7 as an electricity conductive material is fitted into this groove 5 so as to be interposed between the respective welded portions which metallic wire is coated with a coating synthetic resin 6 which is identical to a material of the welded portions and formed in a loop fashion similarly to the groove 5, and heat is generated in the metallic wire 1 by eddy current by placing the metallic wire in a high-frequency magnetic field, whereby the coated synthetic resin of the metallic wire 7 is first fused by heat so generated and then the respective welded portions are fused for integral joint.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for electromagnetically welding a large synthetic resin member such as a toilet seat of a Western style toilet.

[0002]

2. Description of the Related Art A toilet seat of a Western-style toilet has a toilet seat body forming a seat surface and a bottom plate for closing a lower surface of the toilet seat body, which are joined by ultrasonic welding, hot plate welding, or vibration welding. And electromagnetic induction welding. (1) Ultrasonic welding is performed by providing a gap or a step between the toilet seat body and the bottom plate except for the welded parts of both parts so that they do not directly touch each other. The welded portions are joined by heating and melting between the welded portions by applying vibration pressure. However, in this case, the gap or step provided between the toilet seat main body and the bottom plate cannot be completely closed, so that dirt may enter the remaining gap or step. Moreover, the surface is easily scratched by vibration applied during welding, and often requires post-finishing to remove the scratches. Also, for ultrasonic welding between the toilet seat body and the bottom plate, ABS resin (acrylonitrile butadiene styrene resin) or the like is suitable for both materials, but this ABS resin is disadvantageous in that it is cracked by toilet detergent. There is. To improve chemical resistance, PP resin (polypropylene resin) is preferably used, but ultrasonic welding is difficult due to the size of the toilet seat body and the bottom plate, which are large synthetic resin molded members, and ,
Due to the low surface hardness, the surface is more easily scratched. (2) Hot plate welding involves interposing a hot plate (heater) between the welded portions of the toilet seat body and the bottom plate to heat and fuse the welded portions, quickly pull out the hot plate and pressurize the two. The welds are joined together. However, in this case, when the hot plate is inserted, a sufficient opening interval is required between the toilet seat body and the bottom plate, and if this interval is small, the peripheral wall of the toilet seat body is thermally deformed. In addition, it is difficult to control the height direction (step), and the opening state fluctuates due to a difference in the molding dimension between the toilet seat main body and the bottom plate. Therefore, the yield is poor and the quality remains problematic. (3) In vibration welding, the bottom plate vibrates horizontally while the toilet seat body and the bottom plate are pressed against each other at the welded portions, and the welded portions are fused by frictional heat between the welded portions due to the vibration. By doing so, the welded portions are joined to each other. However, in this case, a portion other than the welded portion may touch and melt due to a change in the degree of pressurization or a molding dimension between the toilet seat body and the bottom plate, and this may protrude to the outside. In addition, a positional shift between the toilet seat body and the bottom plate may occur. Therefore, joining is not easy, often requires post-processing, and the appearance often deteriorates. (4) The electromagnetic induction welding involves interposing a wire formed in a loop along the welded portion between the loop-shaped welded portions of the toilet seat body and the bottom plate to generate an eddy current in the wire by a high-frequency magnetic field. The heat generated by the eddy current causes the welded portions to melt with each other, and pressurize and join the two. However, in this case, in a place where the state of heat transfer from the wire is poor, a poor bonding may occur locally due to insufficient melting. Such a local joint failure allows water to enter the inside, causing failure of the internal heating heater, etc., electric leakage,
There is a risk of causing an electric shock, and the wire may rust, which may destroy the welded portion. In order to remedy such inconvenience, it has been attempted to generate heat due to hysteresis loss in the magnetic sheet by interposing a magnetic sheet between the welding portions instead of wires, but this magnetic sheet is used as a toilet seat body. Heat is induced in the aluminum foil or the like surrounding the heater for heating, and the performance of the heater for heating cannot be guaranteed. In addition, various problems remain in incorporating the magnetic sheet, and the cost increases. Therefore,
It cannot be adopted at present.

[0003]

Since the above-described electromagnetic induction welding generates heat due to eddy current in the wire, the wire can accurately generate heat, and therefore, heat can be transferred from the wire. As long as the condition is good, it is possible to reliably obtain a predetermined melting at the welded portion, the melting state can also be appropriately controlled externally, high mechanical strength, high reliability, beautiful appearance, and Welding in a short time can be obtained. Therefore, the present invention improves the state of heat transfer from the wire in electromagnetic induction welding, ensures that the entire welded portion can be melted, eliminates local joining defects, and prevents water from entering due to joining defects. It is intended to eliminate the risk of failure, leakage, and electric shock of the internal heating heater and the like, and to eliminate the rust of the wire and the destruction of the welded portion due to the rust.

[0004]

In order to achieve the above object, the present invention is directed to a method for coating two large synthetic resin members to be welded between the welded portions with a synthetic resin similar to the welded portions. With the conductive material interposed, the conductive material is placed in a high-frequency magnetic field to generate heat due to eddy currents. And joined together.

The invention according to claim 2 is characterized in that the welding portions 3 and 4 on the inner and outer peripheral edges of the toilet seat body 1 and the bottom plate 2 of the Western style toilet, which are large synthetic resin members to be welded, are located on the toilet seat body 1 side. A groove 5 which loops in a loop is formed on the opposite surface of one of the welded portions of the welded portion 4 and the bottom plate 2, and a coating synthetic resin 6 of the same material as the welded portions 3, 4 is formed in the groove. Wire 7 which is a conductive material and is covered with
The wire is placed between the welded portions 3 and 4, and the wire is placed in a high-frequency magnetic field to generate heat due to the eddy current in the wire. It is characterized in that the parts 3, 4 are melted and joined together.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION

1. 1. FIGS. 1 to 4 show an embodiment 1 according to the first and second aspects of the present invention. 1 to 4, reference numeral 1 denotes a toilet seat body of a Western-style toilet which is a large synthetic resin member to be welded, and 2 denotes a bottom plate provided on a lower surface of the toilet seat body, and these are injected by PP resin (polypropylene resin). Formed by molding. In FIG. 2, 9 is a heater for heating adhered to the inner surface of the toilet seat main body, and 10 is an aluminum foil for protection adhered to the outside of the heater for heating.

[0007] As shown in FIGS. 1 and 2, the toilet seat body 1 and the bottom plate 2 have welding portions 3 and 4 in a loop shape facing each other on the inner peripheral edge and the outer peripheral edge. . As shown in FIG. 3 in an inverted posture, grooves 5 are formed along the welded portions in a loop on the facing surface of the welded portions 3 on the toilet seat body 1 side, and the welded portions of the bottom plate 2 are formed. In FIG. 4, a ridge 8 that is larger than the width of each groove 5 and taller than the groove depth of each groove 5 and has a sharp tip is made to loop around the respective grooves 5 in a loop shape. Has formed.

Then, the toilet seat body 1 and the bottom plate 2 are inverted as shown in FIG. 3 so that the synthetic resin of the same material (PP resin) as the welded portions 3 and 4 is provided in each of the grooves 5. Wires 7 serving as conductive materials, which are covered with the coating 6 and formed in the same loop shape as the respective grooves 5, are respectively fitted with the coating synthetic resin 6, and only a part of each coating synthetic resin 6 is projected. The wire 7 and its synthetic resin 6 have a concentric circular cross section. The diameter of the wire 7 is preferably about 0.4 mm. Next, as shown in FIGS. 3 and 4, in the inverted posture,
The bottom plate 2 is overlaid on the toilet seat body 1 from above, and high-frequency magnetic lines of force 12 are applied from the surrounding electromagnetic coils 11 while being pressed down. That is, the base material is placed in a high-frequency magnetic field. As a result, an eddy current is generated in each wire 7, and the coating synthetic resin 6 is first melted by the heat generated by the Joule heat due to the eddy current, and then the welded portions 3 and 4 are successively melted.
The two are joined together. In this case, the coating synthetic resin 6
Is in close contact with the peripheral surface of the wire 7 and is surely melted in each part, and this melting leads to fusion of the welded parts 3 and 4, so that the welded parts 3 and 4 are bonded and integrated generally accurately. Is done.

FIG. 5 and FIG. 6 show that the bottom plate 2 is fitted inside the toilet seat main body 1 in the above-mentioned first embodiment, and the fitting surface is tapered. Others are the same as in the case of 1, and the description is omitted.

[0010]

According to the first and second aspects of the present invention,
Because of the configuration described above, in electromagnetic induction welding, a conductive material,
The synthetic resin coating the conductive material and the coated synthetic resin 6 can be first reliably melted by the heat generated by the eddy current of the wire 7, and the fusion can lead to the fusion between the welded portions.
Therefore, it is possible to improve the state of heat transmission between the welded portions, to reliably perform the melting at the entire welded portion, to eliminate the local bonding failure, and to accurately and accurately bond the welded portions to each other. It can be joined and integrated. Of course, the advantages unique to electromagnetic induction welding, which are not found in other various welding means, can be fully exhibited, and high mechanical strength, high reliability, beautiful appearance, and short time welding can be achieved. Obtainable.

According to the second aspect of the present invention, in addition to the above-described effects, it is possible to eliminate the intrusion of water due to poor connection, and to eliminate the risk of failure, electric leakage, and electric shock of the internal heating heater and the like. In addition, rust of the wire and destruction of the welded portion due to this can be eliminated.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment 1 according to the first and second aspects of the present invention.

FIG. 2 is an enlarged cross-sectional view taken along line AA of FIG.

FIG. 3 is an explanatory sectional view showing a main part of Embodiment 1 of the present invention before welding, which is enlarged and inverted.

FIG. 4 is an explanatory cross-sectional view after welding, showing a main part of Embodiment 1 in an enlarged and inverted manner.

FIG. 5 is an explanatory sectional view showing a main part of a second embodiment before welding, which is shown in an enlarged and inverted manner.

FIG. 6 is an explanatory sectional view showing a main part of the second embodiment after welding, which is enlarged and inverted to show a main part.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Toilet seat main body 2 ... Bottom plate 3 ... Welding part 4 ... Welding part 5 ... Groove 6 ... Coating synthetic resin 7 ... Wire 8 ... Ridge 9 ... Heating heater 10 ... Aluminum foil 11 ... Electromagnetic coil 12 ... Magnetic force line

Continuation of the front page (72) Shingo Muramatsu, Inventor Shingo 3000, Mita, Atsugi-shi, Kanagawa Prefecture (72) Inventor Akira Oishi 2-1-1 Nakajima, Kokurakita-ku, Kitakyushu-shi, Fukuoka Totoki Kiki Co., Ltd. (72) Inventor Seiichiro Inoue 2-1-1 Nakajima, Kokurakita-ku, Kitakyushu-shi, Fukuoka Prefecture

Claims (2)

[Claims] A conductive material coated with synthetic resin of the same type as the welded portion is interposed between the welded portions of two large synthetic resin members to be welded, and the conductive material is placed in a high-frequency magnetic field. The large-sized synthetic resin member is characterized in that heat is generated in the conductive material by eddy current, and the generated heat firstly joins the synthetic resin covering the conductive material, and then fuses the welded portions together to join them together. Electromagnetic induction welding method. 2. A welded portion 3 on the toilet seat body 1 and a welded portion on the bottom plate 2 side between the welded portions 3 and 4 on the inner and outer peripheral edges of the toilet seat body 1 and the bottom plate 2 of the Western style toilet as a large synthetic resin member to be welded. A groove 5 is formed in the opposite surface of either one of the welding portions 4 and 4 in a loop shape, and the groove 5 is covered with a coating synthetic resin 6 of the same material as those of the welding portions 3 and 4. A wire 7 as a conductive material formed in the same loop shape is fitted and interposed between the welded portions 3 and 4, and the wire is placed in a high-frequency magnetic field to generate heat due to eddy current in the wire. An electromagnetic induction welding method for a large synthetic resin member, characterized in that the wire-coated synthetic resin 6 is then fused together with the welding portions 3 and 4 to be integrally joined.