JPH0114656B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a photoelectric switch, and an object thereof is to provide a photoelectric switch that is small, has excellent airtightness, and whose performance can be easily checked during assembly.

Conventional photoelectric switches, for example,
No. 25687 shows that the case member is divided and requires ultrasonic heat bonding after assembly, and a heat bonding location must be provided, making it impossible to make it compact. In addition, when the light emitting/light receiving element is mounted on a printed board, light enters the light receiving element directly, so it is not possible to perform a static test, and it can only be carried out after being stored in the case member.If it is defective, it can be repaired because it is ultrasonically bonded. is impossible. Furthermore, since the divided case members are thermally bonded using ultrasonic waves, they cannot be made completely airtight, and cannot sufficiently prevent foreign objects such as water droplets and dust from entering the switch during use, making it unreliable as a photoelectric switch. Ta.

The present invention has been made in view of the above-mentioned conventional drawbacks and to improve them.

Embodiments of the photoelectric switch of the present invention will be described below with reference to FIGS. 1 to 9.

The frame body 1 is U-shaped, and a bag-shaped cylinder body 2 is attached to one side 1a.
In addition, protrusions 8, 8, . . . are provided protrudingly, and an engagement hole 5 is bored. On one side 1b is a bag-shaped cylinder 3 and protrusions 9, 9.
... are provided protrudingly, and an engagement hole 6 is bored. 1 side
A hole 7 and a hole 4 for pulling out the cord 13 are bored in the hole 7, and protrusions 10, 10, . . . are provided in a protruding manner. The frame body 1 is made of a transparent synthetic resin material to allow light to pass through.

The printed board 15 has engaging protrusions 14, 14, 14
is provided protruding from the periphery, and a light emitting or light receiving element 11, a display element (light emitting diode, lamp, etc.) 12, and a cord 13 for output transmission to the outside and power input are electrically connected to the circuit section. Further, a dustproof and waterproof bushing 13a is fitted onto the cord 13.

Position the printed board 15 inside the frame 1,
The projections 14, 14, 14 are inserted into the engagement holes 5,
6 and 7 to hold the printed board 15 inside the frame 1, and in this state, a mold abutting surface is formed around the frame 1 by molding simultaneously with the plastic molding of the main body case member 16.
The main body case member 16 is attached by molding the PL molds together. At the time of this molding, the cylinders 2, 3 and the protrusions 8, 9, 10 are formed into a mold so that they are exposed or protrude from the outer surface of the main body 16 as shown in the figure. Since the main body case member 16 can be held at a predetermined position within the mold, the main body case member 16 can be accurately attached around the frame body 1. Since the main body case member 16 is attached to the frame body 1 by a molding operation, it is small in size, and the main body case member 16, the cylinder bodies 2 and 3, and the bush 1
3a, a completely airtight state is created by the molding pressure, resulting in a highly reliable photoelectric switch.

In the embodiments shown in FIGS. 7 to 9, the emitter and light receiver
It is a so-called reflective photoelectric switch equipped with 1 and 11', and the cylindrical body 2 has two bottomed holes. Light-receiving elements 11 and 11' are housed therein, and in addition to a (light-emitting element) display element 12, a variable resistor 12' for sensitivity adjustment is also housed in the cylinder 3. Since the variable resistor 12' is adjusted, a small hole is provided in the bottom wall of the cylinder 3 protruding from the main body case member 16, but the outer periphery of the variable resistor and the inner wall of the cylinder are sealed with adhesive or may be made airtight by press-fitting them together, and the variable resistor 1
The clearance between the movable parts of the adjustment shaft 12'' of 2' is O around the shaft.
It can be easily made airtight by extrapolating the ring.

In addition, as shown in FIGS. 10 to 12, the frame 1 may be provided with a hinge portion H between each side 1a, 1b, and 1c, and the frame may be formed into a predetermined U-shape after molding. Since the frame body 1 is molded only with an upper mold and a lower mold without a slide core, the molding work is easy and the mold structure is simple.

As explained above, according to the photoelectric switch of the present invention, the cylindrical body, protrusions, and cords of the frame body 1 housing the printed board 15 are left in place and attached around the frame body simultaneously with the molding of the main body case member. Because of this, there is no need for extra assembly adhesive points on the main body case member, resulting in a smaller size, and the synthetic resin of the main body case member is airtightly adhered to the periphery of the frame by molding pressure, resulting in high airtightness and high reliability. This is a photoelectric switch, and since the light emitted when the printed board is engaged with the frame is projected in a predetermined direction by the cylindrical part, the performance test can be checked during assembly and any defects can be corrected. It has excellent effects not found in conventional examples.

[Brief explanation of drawings]

1 to 12 show an embodiment of the photoelectric switch of the present invention, in which FIG. 1 is an exploded perspective view of essential parts in a facing type, FIG. 2 is a front view, FIG. 3 is a plan view, and FIG. Figure 2 is an enlarged cross-sectional view of the main part of the light receiving element, Figure 5 is an enlarged cross-sectional view of the main part of the display element, Figure 6 is an enlarged cross-sectional view of the main part of the cord, and Figure 7 is an enlarged cross-sectional view of the main part of the light receiving element. 8 is a front view, FIG. 9 is an enlarged sectional view of the main part of the display element, and FIG. 10 is a perspective view of another embodiment in which the frame has a hinge structure; 11a is a plan view of the main part of the hinge of the frame body, FIG. 11b is a plan view of the hinge in FIG. 11a bent, FIG. 12a is a plan view of another embodiment of the hinge, Figure b is a bent plan view of Figure 12a. 1... Frame body, 1a, 1b, 1c... One side, 2, 3...
Cylindrical body, 4... hole, 5, 6, 7... engagement hole, 8, 9,
DESCRIPTION OF SYMBOLS 10... Protrusion, 11... Light emitting (receiving) element, 12... Display element, 13... Cord, 14... Protrusion, 15... Printed board, 16... Main body case member.

Claims (1)

[Claims] 1. In a photoelectric switch in which a main body case member 16 is attached around a frame 1 housing a printed board 15, the frame 1 is made of transparent synthetic resin and one side 1a of the photoelectric switch is made of transparent synthetic resin.
A bag-shaped cylinder 2 for storing a transmitting or light-receiving element protruding outwardly, and a bag-like cylinder 3 for storing a display element protruding outward on one side 1a or the other side 1b, and either one side. 1a, 1b or the remaining side 1c has a cord pull-out hole 4, each side 1a, 1b, 1c has holes 5, 6, 7 for engaging a printed board, and the outside of each side 1a, 1b, 1c. The printed board 15 has protrusions 8, 9, and 10 protruding from each other, respectively, and the printed board 15 has protrusions 14, 14, and 1 that are engaged with the holes 5, 6, and 7 of the frame 1.
4, a light emitting or light receiving element 11 housed in the cylindrical body 2 and conductively connected to the printed board 15, a display element 12 housed in the cylindrical body 3 and conductively connected to the printed board 15, inserted through the hole 4 and conductively connected to the printed board 15. A main body case member 16 is formed by applying an opaque synthetic resin by plastic molding around the frame 1, leaving the ends of the cord 13, the cylinders 2, 3, and the protrusions 8, 9, 10. A photoelectric switch characterized by: