JPS6235238Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a photoelectric switch, and its purpose is to obtain sufficient sealing without increasing the precision of the parts when attaching a photoelectric element and lens to the body of the photoelectric switch. The aim is to make sure that

As shown in FIG. 2, in the conventional case, a stepped portion 2 is formed on the outer periphery of the opening of a main body 1 made of zinc die-cast, and a cylindrical body 4 (made of zinc die-cast) is formed through a packing 3 or without using a packing 3. ), the inner peripheral wall 5 of one end of the cylinder body 4 is press-fitted and sealed, a synthetic resin holder 8 equipped with a photoelectric element is inserted into the inner peripheral wall 6 of this cylinder 4, and a seal 12 is inserted into the other end of the holder 8 to open the rim 11 of the holder 8. The lens 13 is brought into contact with the annular lens holder 14.
(made of zinc die-casting) and press-fits the lens 13 into the mouth rim 7 of the cylinder body 4. In order to enhance the sealing effect, the seal 3 is attached to the step part 10 of the holder 8 and the inner peripheral protrusion of the cylinder body 4. It was inserted between 4a.

In such conventional photoelectric switches, each part is assembled by press-fitting, so unless the dimensional accuracy of the parts is high, a sufficient sealing effect cannot be obtained, and the already expensive zinc die-cast part becomes even more expensive. There was a drawback. Further, since the lens holder 14 is thick, there is also the drawback that lens dirt cannot be removed sufficiently to the periphery of the lens.

The present invention improves these conventional drawbacks.

An embodiment of the photoelectric switch of the present invention will be described below with reference to FIG.

Engagement piece 2 on the inner periphery of one end of the synthetic resin cylinder 26
A photoelectric element PT (a light emitting element such as an LED, a light receiving element such as a phototransistor) is fixed to 7, and this photoelectric element PT is mounted on a printed board PC. The outer peripheral stepped portion 29 of the cylindrical body 26 is in contact with the inner peripheral stepped portion 23 of the cylindrical portion 22 of the main body 21 via the packing 25. The inner circumferential stepped portion 28 of the cylindrical body 26 is in contact with the lens 31 via a packing 30. One end edge 34 of a substantially cylindrical lens holder 32 made of sheet metal is in contact with the outer periphery of the lens 31, and the other end has an inwardly bent engaging portion 33 that is in contact with the outer periphery recess 2 of the main body 21.
1a, and the gaskets 25 and 30 are in close contact with each other.

An engaging portion 36 of a flexible protective tube 35 made of rubber or the like is locked in the recess 21a to cover the outer periphery of the lens. The protective tube is flexible, so when cleaning the lens, you can easily wipe it all around the lens, leaving no residue behind. In addition, if the tip 37 of the protective tube 35 is narrowed down as shown in Figure 1, it is easy to change the operating angle necessary to prevent interference that occurs when photoelectric switches are connected and mounted, and an inexpensive protective tube can be prepared separately. For example, expensive main bodies can be used commonly, and replacement at the installation site is easy and reasonable.

However, since the expensive zinc die-cast parts are made only of the main body 21 and are not press-fitted, the accuracy of the parts is lower than that of press-fitted parts, and can be made at a lower cost.Furthermore, the lens holder 32 is made of sheet metal and can be made thinner. , the area around the lens can be thoroughly wiped off.

As explained above, according to the photoelectric switch of the present invention, the lens holder is made of metal sheet metal and the gaskets are tightly fixed at both ends to the recess of the main body and the outer periphery of the lens, so that the main body, which is a zinc die-cast part, can be manufactured at low cost. Further, the lens can be wiped securely to the periphery, and maintenance is also easy.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention. FIG. 2 is a sectional view showing a conventional example. 21...Main body, 21a...Indentation, 22...Cylinder part, 23...Inner peripheral stepped part, 25...Putskin, 26
... Cylindrical body, 28 ... Inner circumference step, 29 ... Outer circumference step, 30 ... Packing, 31 ... Lens, 32 ...
... Lens holder, 33 ... Engagement part, 34 ... Mouth rim.

Claims (1)

[Scope of utility model registration request] A photoelectric element is attached to the inner periphery of one end of the cylindrical body, and a lens is brought into contact with the inner periphery step of the other end through a gasket, and the distance between the outer periphery step of the cylindrical body and the cylindrical inner periphery step of the main body of the photoelectric switch is are in contact with each other through gaskets, one end edge of a lens holder made of a substantially cylindrical metal plate is in contact with the outer periphery of the lens, and the other end is in close contact with a recess in the outer periphery of the main body cylindrical portion. A photoelectric switch characterized by being locked.