| 摘要 |
PURPOSE:To smoothly insert a bulb fitted with a base into and detach the bulb out of a bulb insertion hole and make the sealing surely reliable by an O-ring set between the bulb furnished with a base and the bulb insertion hole. CONSTITUTION:An insertion structure is composed of a circular bulb insertion hole 40 formed in a reflector 1 and a bulb furnished with a base to be inserted into the insertion hole 40 through an O-ring 30. A disk-like joining part 25 which can be joined with the bulb insertion hole 40 is formed in a base main body 20 made of synthetic resin to support a bulb main body (electric bulb) and a recessed groove 26 is formed in the outer circumferential face of the disk-like joining part 25 and the O-ring 30 to be pressed to the inner circumferential face of the bulb insertion hole 40 of the reflector 1 is set in the recessed groove 26. The groove width W of the recessed groove 26 is made wider than the diameter D of the circle of the circular cross-section shape of the elastic sealing member 30, so that prescribed uniform contacting pressure can be obtained in the circumferential direction and the bulb can be attached and detached smoothly. The O-ring 30 is prevented from dropping out of the recessed groove 26 by making the groove depth deeper than a half of the diameter D of the circle. |
