JPH0283491A - Photoelectric switch - Google Patents

Abstract

PURPOSE:To prevent the generation of erroneous operation caused by the adhesion of cutting oil or powder by blowing off the cutting oil or powder in the directions respectively isolated from a light emitter and a photodetector by ejecting air from the interior of a hermetically closed housing through an opening. CONSTITUTION:At the time of the operation of a machine tool, high pressure air is sent in hermetically closed housings 10, 20 through high pressure air supply pipes 15, 25 and emitted outwardly through openings 1a, 2a. Therefore, the cutting oil or powder adhered to or ready to be adhered to the peripheries of openings 12b, 22b are blown off not to intercept an optical axis Q. A part of high pressure air is emitted through the gap between the signal cable 1a of a light emitter 1 and a notch 11a and the gap between the signal cable 2a of a photodetector 2 and a notch 21a to prevent the invasion of the cutting oil. By this method, the generation of erroneous operation is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a photoelectric switch consisting of a combination of a pair of light emitters and a light receiver.

[Conventional technology]

This type of photoelectric switch is widely used in production machinery and the like because it can detect objects without contact. 3 to 5 show a machining machine employing the above photoelectric switch.

When the workpiece W is placed on the bed B of the machine tool A, and then the workpiece W is butted against the rough guide C1C on the bed B, a part of the workpiece W gets between the light emitter and the light receiver E. When the light F from the light emitter is blocked by a part of the workpiece W, the photoelectric switch detects that the workpiece W is in the correct position. Based on this detection signal, the dowel pin G in the bed B rises and fits into the positioning hole Wa of the workpiece W, and the clamper H clamps the workpiece W, thereby fixing the workpiece W to the bed B, and then the head I starts operating, and the workpiece W is machined by the tool J attached to the head I.

[Problems to be Solved by the Invention] By the way, in the above-mentioned machine tool A, when machining the workpiece W, a large amount of cutting oil is supplied from the pipe K toward the machining machine AJ. If the chips and cutting oil blown away by the light-emitting device adhere to the starting part Da of the light emitting device or the light-receiving part Ea of the light receiver E, the photoelectric sensor may malfunction and the machine tool A may not operate normally. There is.

One way to solve this problem is to cover the head side (upper part in the figure) of the optical instrument and receiver E and secure them with a cover M, as shown in Fig. 6.
There is no way to prevent the cutting oil and chips from bouncing back from the bed B and the workpiece W, and the optical path may be blocked by the cutting oil dripping from the ends of the covers L and M, which may even cause the photoelectric switch to malfunction. There is.

In addition, as a measure to prevent malfunction of the photoelectric switch, as shown in Fig. 7, there is a structure in which air nozzles N and O are provided to blow off cutting oil and chips adhering to the light emitting part Da and the light receiving part Ea with air. However, the blown chips may damage the light tip Da and the light receiving part Ea, which are generally made of plastic material, which may lead to malfunction of the photoelectric switch.

In view of the above-mentioned circumstances, it is an object of the present invention to provide a photoelectric switch that can prevent malfunctions caused by adhesion of cutting oil and chips.

[Means for Solving the Problems] This light emitter houses and installs a light emitter and a light receiver in each sealed housing, and an optical axis connecting the light transmitter and the light receiver is installed on the wall plate of each sealed housing. An opening was formed to pass through the casing, and a high-pressure air supply pipe was connected to each sealed casing.

(Function) Air is blown out from within the sealed housing through the opening, thereby blowing the cutting oil and powder away from the light emitter and the light receiver, respectively.

〔Example〕

Hereinafter, the present invention will be explained in detail based on the drawings.

1 and 2 show a photoelectric switch according to the present invention. This photoelectric switch 100 includes a light emitter 1 and a light receiver 2, which are arranged opposite to each other. has been done.

The sealed casing 10 includes a box-shaped casing main body 11 that is open at the top and the front, and a transparent acrylic body 1 that is made of a transparent acrylic material and has a cross-sectional shape.
2 is facing, and there is a paragin 1 for one stop on the housing body 11.
It is constructed by screwing the benefit body 12 through 3. A light device 1 is fixedly installed in the housing body 11 via a member 14, and a signal cable 1a of the light source is connected to a U-shaped cut formed in the housing body 11. It is taken out to the outside of the sealed casing 10 via the notch 11a. On the other hand, an opening 12b is formed in the front plate 12a of the beneficial body 12 at a position through which the optical axis Q connecting the light emitter 1 and the light receiver 2 passes, as shown in FIG. Furthermore, the sealed housing 10
A mounting hole 11b# is provided in the main body 11 of the housing, and a high-pressure air supply pipe 15 extending from a high-pressure air supply source such as an air pump (not shown) is connected to this hole 11b.

The sealed casing 20 that houses the light receiver 2 has the same structure as the above-described sealed casing 10, and elements having the same functions as the components of the sealed casing 10 are designated with 20s. The explanation will be omitted.

FIG. 1 shows a third photoelectric switch 100 according to the present invention.
This figure shows an example in which it is mounted on a machine tool as shown in the figure, in which reference numeral 30 is a bed and 40 is a workpiece.

During operation of the machine, air is supplied to the inside of the closed housings 10 and 20 for 0.5 h via high-pressure air supply pipes 15.25.
/ cd ~ 9 / cd high pressure air is sent to 5, and this high pressure air is connected to arrows r, r, a5 and arrow S
, S, an opening 12a is opened from inside the sealed housing 10.20.
, 22a to the outside. Thus the opening 12b
, 22b, the cutting oil and cutting oil that have adhered or tried to adhere to the vicinity of the optical axis Q are blown off by the ejected air as described above, and the optical axis Q is not blocked by chips or the like.

On the other hand, a part of the high-pressure air supplied into the sealed casing 10.20 flows between the signal cable 1a of the light emitter 1 and the notch 11a, and the light receiving It passes between the signal cable 2a of the device 2 and the notch 21a and ejects to the outside, thereby causing the sealed casing 10.20
This prevents cutting oil from entering the inside.

Furthermore, since the lid body 12.22 constituting the sealed casing 10.20 is made of a transparent material, even if the formation positions of the openings 12b and 22b are shifted, the light from the flower light device 1 will still be transmitted through the lid. It passes through the body 12.22 and reaches the light receiver 2 without any hindrance. Furthermore, since the lid body 12゜22 is a transparent body, the light emitting device 1
and the light receiver 2, the ED indicator light can be easily seen.

Although a machine tool is illustrated in this example, it goes without saying that the photoelectric switch according to the present invention can be effectively applied to various production machines and the like.

〔Effect of the invention〕

As detailed above, according to the photoelectric switch related to the present invention, high-pressure air is blown out from the sealed housing housing the light emitter and the light receiver through the opening through which the optical axis passes. Foreign substances such as cutting oil and chips on the optical axis are blown away by the high-pressure air. In this way, malfunctions caused by the foreign matter can be prevented.

[Brief explanation of the drawing]

Fig. 1 is an overall side sectional view of a photoelectric switch according to the present invention, Fig. 2 is an overall exploded perspective view of the sealed casing, Fig. 3 is an overall perspective view of a machine tool using the photoelectric switch, and Fig. 4. 5 is a plan view and a side view of a main part of the machine tool shown in FIG. 3, and FIGS. 6 and 7 are conceptual side views of a conventional photoelectric switch and its surroundings without showing them. DESCRIPTION OF SYMBOLS 1... Emitter, 2... Light receiver, 10.20... Sealed housing, 12a, 22a... Opening, 15.25...
High pressure air supply pipe, 100...photoelectric switch. Applicant: Suzuki Motor Corporation...-1f1
c・1 Figure 1 Figure 3 Figure 4 Figure 5 Figure 2 Figure 7 Figure 6

Claims (1)

[Claims] A light emitter and a light receiver arranged to face each other are each housed and installed in a sealed housing, and an optical axis connecting the light emitter and the light receiver is passed through a wall plate of each of the sealed housings. A photoelectric switch characterized in that an opening is formed, and a high-pressure air supply pipe is connected to each of the sealed casings, so that air is blown out from within each of the sealed casings through the openings.