JPS6410892B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field: This invention relates to a photoelectric switch, and particularly to its assembly.

"Conventional Devices and Their Problems" Conventionally, this type of photoelectric switch has two separate case parts that are joined together only with adhesive, but this is difficult to work with, and because the adhesive has fluidity. , it is difficult to handle, especially in narrow areas, and to solve this problem, it is possible to join the case parts only by ultrasonic welding, but there are holes for sensitivity adjustment and holes for indicator lights between the joint surfaces. In such cases, problems arise in the sealing properties.

Furthermore, as shown in FIG.
2, the O-ring 31, the lens plate 35, and the presser frame 34 are stacked one after another, and the presser frame 3
4 is fixed to the case 1, but since a pressing force is applied to the O-ring 31 in the axial direction, there is a risk that the sealing performance between the presser frame 34 and the case 1 will not be stable.

"Objective" In view of these conventional problems, it is an object of the present invention to provide a photoelectric switch with good sealing properties and high working efficiency.

"Embodiment" An embodiment of the present invention will be described below with reference to the drawings.

That is, in FIGS. 1 to 7, a case 1 is formed by a pair of case parts 3 and 4 that are divided approximately symmetrically along its axis, and a window 11 is provided in a first side wall 5 of the case. Further, the second side wall 6 of the case 1 is provided with a window 13 for adjusting the sensitivity regulator 12 and a window 15 for the indicator light 14, respectively. Furthermore, a protrusion 17 is integrally formed on the abutting edge of one of the case portions 3 of the first side wall 5, third side wall 7, and fourth side wall 8 of the case 1. The printed circuit board 19 constitutes a switching circuit and is housed within the case 1. The holder 21 holds a light emitting element 22 or a light receiving element 23, and has windows 25 and 26 in the corresponding portions of these elements. The holder has a flange 27, and a groove 28 is formed at the rear of the holder along its entire circumference. This groove is formed in the shape of a mountain with an inclination of approximately 15 degrees on the upper and lower sides of the holder 21, and the cross-sectional shape along the groove is hexagonal, and each corner has a predetermined curvature. ing. A seal ring 31 is fitted into this groove. A groove 32 is provided at the peripheral edge of the window 11 of the case 1, and the flange 27 of the holder 21 fits into this groove. Furthermore, a hexagonal rib 33 is formed on the case 1 at the rear of the groove 32 in correspondence with the groove 28, and the seal ring 31 is compressed between the holder 21 and the case parts 3 and 4 in a state where the two case parts 3 and 4 are connected. .

Lens plate 35 covering the front of holder 21
has a protrusion 36 on the peripheral edge of the surface that comes into contact with the holder 21.

"Assembling method" To assemble the photoelectric switch in the above configuration, first install the printed circuit board 19 in one case part 3.
Then, the holder 21 with the seal ring 31 fitted into the groove 28 is fitted into the groove 32 of the case part 3. Next, attach the other case part 4 to the holder 21
At the same time, its edge abuts the edge of one of the case parts 3, and furthermore, the lens plate 35 is stacked on the front surface of the holder 21. In this state, the energy director 37 is set on the case 1 on the circumference of the seal ring 31, and when ultrasonically welded,
The protrusions 17 and 36 are melted, and the case parts 3 and 4 are combined to form the case 1, and the lens plate 35 is integrated with the holder 21. Further, by flowing adhesive into the abutting edges of both case parts 3 and 4 in the second side wall 6 of the case 1, this part is joined and sealed.

In this state, the seal ring 31 is compressed between the holder 21 and the case 1, that is, between the groove 28 and the rib 33, and a seal is formed between the holder 21 and the case 1.

Note that the lenses 39 and 40 of the lens plate 35 are located within the windows 25 and 26.

"Effects" As described above, this invention provides protrusions on the abutting edges of the first, third, and fourth side walls of the case, and melts the protrusions by ultrasonic welding to connect both case parts together. In addition, since both case parts are connected using an adhesive on the second side wall of the case in which the window for sensitivity adjustment or the window for the indicator light is provided, there is an advantage that the sealing property thereof is extremely good.

The holder and lens plate are also joined by ultrasonic welding, which increases their sealing performance.Furthermore, the outer periphery of the holder has a groove into which the seal ring fits, and the case has a groove that fits into the groove. A rib is provided in between to sandwich the seal ring,
Furthermore, the cross-section of the rib and groove along the groove is approximately hexagonal, and the case of the light emitting or receiving window is provided with a rib that compresses the seal ring along with the groove. This has the effect of not only improving the sealing performance, but also being able to press the seal ring at the same time when connecting the pair of case parts.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view of a photoelectric switch showing an embodiment of the present invention, Fig. 2 is an external perspective view, Fig. 3 is a front view, Fig. 4 is a plan sectional view, and Fig. 5 is a rear view of the holder. , FIG. 6 is a side sectional view showing the state of both case parts before welding, FIG. 7 is a side sectional view showing the welded state, and FIG.
The figure is an exploded perspective view of a vertical photoelectric switch. 1...Case, 3...Case part, 4...Case part, 5
...first side wall, 6...second side wall, 7...third side wall, 8...fourth side wall, 11...window, 12...sensitivity adjuster, 13...window, 14...indicator light, 15...window, 17...
Projection, 19... Printed circuit board, 21... Holder, 22... Light projecting element, 23... Light receiving element, 25...
Window, 26... Window, 27... Flange, 28... Concave groove, 31...
Seal ring, 32...concave groove, 33...rib, 35...
Lens plate, 36... Projection, 37... Energy director, 39... Lens, 40... Lens.

Claims (1)

[Claims] 1. A case housing a light emitting element or a light receiving element and a switching circuit is formed by a pair of case parts divided approximately symmetrically along its axis, and the first side wall of the case is provided with a light emitting or light receiving element. and a window for sensitivity adjustment or a window for an indicator light is provided on the second side wall of the case,
Further, in the first, third and fourth side walls of the case, the abutting edge of either one of the case parts and the peripheral edge of the lens plate covering the light emitting or light receiving window. Protrusions are provided respectively, and both the case parts are welded by ultrasonic welding on the first, third and fourth side walls, and the case and the lens plate are welded by ultrasonic welding, and the case the second of
Both of the case parts are bonded with adhesive on the side wall of the window, and a holder for holding the light emitting element or the light receiving element is fitted into the light emitting or light receiving window, and a seal ring is attached to the outer periphery of this holder. Further, the case is provided with a rib for sandwiching the seal ring between the case and the groove, and the cross-sectional shape of the rib and the groove along the groove is approximately 6 mm. The photoelectric switch is formed into a rectangular shape, and in the light projecting or light receiving window, the case is formed with a rib for compressing the seal ring together with the concave groove.