| 摘要 |
<p>An O-ring shaped annular rib 63 is disposed around the outer periphery of a flexible diaphragm member 62, and grooves 70 and 71 are formed for receiving the annular rib 63 in the hollow space in the compressed state wherein the foregoing hollow space is defined between a first synthetic resin member 60 for holding the diaphragm 62 in the clamped state and a second synthetic resin member 61. While the annular rib 63 is received in each of the grooves 70 and 71, a location 64 where the first synthetic resin member 60 and the second synthetic resin member 61 come in contact with each other at the positions located outward of the grooves 70 and 71 is subjected to welding with the aid of a supersonic welding tool 65. A gap 76 is formed between the first synthetic resin member 60 and the supersonic welding tool 65, and this gap 76 is caused to disappear by progressively performing a welding operation. At this time, further proceeding of the welding operation is inhibitively suppressed by allowing the first synthetic resin member 60 and the supersonic welding tool 65 to come in contact with each other, and the compression rate specified for the annular rib 63 is kept constant. Alternatively, a metallic spacer 77 is interposed between the first synthetic resin member 60 and the second synthetic resin member 61. In this case, a gap 78 is formed in the hollow space defined by the second synthetic resin member 61 and the metallic spacer 77 prior to a welding operation, and this gap 78 is caused to disappear as the welding operation is progressively performed so as to allow further proceeding of the welding operation to be inhibitively suppressed. At this time, the compression rate specified for the annular rib 63 is kept constant. <IMAGE></p> |
