JP2554654Y2 - Optical detector - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical detection device for optically detecting various situations such as the presence or absence of an object.

[0002]

2. Description of the Related Art An optical detection device used for detecting the presence or absence of steel in a steel production line includes a transmission type or reflection type optical detector having a pair of a light emitter and a light receiver, and a radiation type optical detector. General.

FIG. 4 shows the above-mentioned transmission type optical detector.
In this arrangement, a light projector (13) and a light receiver (14) are arranged on both sides of a detection space (m) to be detected so that their optical axes coincide. Light (laser light, infrared light, etc.) emitted from the light projector (13) passes through the detection space (m) and is received by the light receiver (14). When a detection target such as steel is present in the detection space (m), the light of the light projector (13) is blocked by the detection target and does not enter the light receiver (14). In the determination of the output level of the light receiver (14), the presence or absence of the detection target in the detection space (m) is detected.

[0004]

The performance of the above-described optical detection device may be affected by the environment in which it is used.

[0005] That is, for example, dust may float in a space to be detected in a steel production line, or steam generated when cooling high-temperature steel may flow into the space. The light of the light projector projected on the detection target space is refracted by floating dust and vapor in the detection target space, and the amount of light incident on the light receiver decreases, and the light receiver may malfunction.

An object of the present invention is to provide a high-performance and highly-reliable optical detector for detecting a detection object without being affected by dust and vapor even if the dust and vapors float in the detection object space unintentionally. It is to provide a device.

[0007]

According to the present invention, an optical detector for optically detecting an object to be detected by directing an optical axis to the object to be detected, and a straight line having an air suction port at one end and an air discharge port at the other end. A through hole is formed.
Compress the compressed air supplied from the pipe toward the discharge hole.
It has a nozzle that sprays in a spiral, and this spiral
Outside air sucked from the air suction hole by the air flow
And a through-type air gun that joins the spiral air and jets the jet air from the air discharge hole in the direction of the center line of the through-hole. Center line of the optical detector coincides with the optical axis of the optical detector and does not hinder the intake of outside air.
As described above, the optical axis of the optical detector is located in the air jet flow path of the air jetted from the air gun by arranging the optical detector between the optical detector and the object to be detected while maintaining the interval with the optical detector. The purpose is achieved.

[0008]

[Function] Spiral is supplied from the pipe at the approximate center of the through hole.
A large amount of compressed air that blows out from the air suction hole
Invites outside air as secondary air, large air volume
It becomes jet air and blows out from the air discharge hole.
This jet air blows air
Strong because it is converged by the twisting effect of
Act by force. Keep the optical detector away from the air suction hole.
It does not hinder the above-mentioned outside air suction.
The air suction can be performed efficiently. Like this
The obtained jet air flows in the space between the optical detector and the inspection object, blows off dust and vapor floating in this space, and forms a clean air jet channel in the space.
The optical axis of the optical detector is located in this air jet channel, and the optical detector always detects the detection target through a clean space.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The first to third embodiments shown in FIGS. 1 to 3 will be described below in order.

The optical detecting device shown in the first embodiment of FIG. 1 includes a transmission type optical detector (1a) and a penetrating type air gun (3). The optical detector (1a) has the same structure and function as the optical detector of FIG. 4, and a pair of a light emitter (13) and a light receiver (14) are opposed to both sides of a detection space (m) to be detected. Let it be arranged.

The penetrating air gun (3) includes a cylindrical nozzle (4) and a pipe (6) for sending compressed air (9) into the nozzle (4). A straight through hole (5) is formed in the nozzle (4) in the axial direction. The opening at one end of the through hole (5) is an air suction port (7), and the opening at the other end is an air discharge port (8).
It is. At the approximate center of the through hole (5), press the compression
Air reservoir (6a) is provided to receive the air (9)
From the air reservoir (6a) to the air discharge hole (8).
When the compressed air is sprayed in a spiral shape, the outside air is sucked into the through hole (5) from the air suction port (7) and merges with the compressed air (9) to form a large air jet.
And jets out from the air discharge port (8). this
The air jet is spiraled from the air pool (6a)
Convergent force due to twisting action by injected compressed air
To act with a strong force far away.

In the embodiment shown in FIG. 1, the nozzle (4) of the air gun (3) is disposed between the light emitter (13) and the detection space (m) to be detected with the position regulated as follows. Floodlight (13)
And the center line of the through hole (5) of the nozzle (4) substantially coincides with the optical axis (2a) of the light receiver (14), and the nozzle (4) is
Place it in front of 3) so as not to hinder air suction . Further, the air suction port (7) of the nozzle (4) is directed toward the projector (13), and the air discharge port (8) is directed toward the detection space (m).

When the optical detector (1a) is operated in the state shown in FIG. 1, the light of the projector (13) is transmitted through the through-hole (5) of the nozzle (4).
Then, the light passes from the detection space (m) to the light receiver (14), and the presence or absence of a detection target in the detection space (m) is detected. In parallel with this optical detection operation, the nozzle (4) of the air gun (3)
Supply compressed air (9) to.

Then, the air discharge port (8) of the nozzle (4)
An air jet is ejected from the nozzle toward the detection space (m) and the light receiver (14), and an air jet flow path (10) is formed between the nozzle (4) and the light receiver (14). If the air sucked into the air suction port (7) of the nozzle (4) or the compressed air (9) of the pipe (6) is kept clean, the air jet channel (10) becomes a clean air tunnel. The air jet channel (10) crosses the detection space (m) to be detected and reaches the light receiver (14). For example, when dust is floating in the detection space (m), the floating dust is blown off by an air jet crossing the detection space (m), and the air jet flow path (10) in the detection space (m) is clean air. It becomes a tunnel.

Therefore, the light of the light emitter (13) always passes through the clean air jet channel (10) without being affected by the floating dust and vapor in the detection space (m), and the light of the light receiver (14).
, There is no fear that the photodetector (14) malfunctions.

The operation of the air gun (3) is based on the fact that the amount of suspended dust and vapor in the detection space (m) is determined by the optical detector (1a).
May be set only when the value exceeds a certain reference value that deteriorates the performance of. For example, if the air gun (3) is supplied intermittently by supplying compressed air (9) to the air gun (3) in response to a light quantity reduction signal to the light receiver (14), useless movement is eliminated, and the energy saving type It will be.

Although not shown, the nozzle (4) of the air gun (3) is connected between the light receiver (14) and the detection space (m).
Further, the air discharge port (8) may be arranged facing the direction of the detection space (m). In addition, you may arrange | position to both a light projector and a light receiver.

The optical detector of the second embodiment shown in FIG. 2 includes a reflection type optical detector (1b) and an air gun (3) similar to the above. The reflection type optical detector (1b) has a built-in light emitter and light receiver, emits light to the detection space (m) of the detection target, and receives reflected light from the detection target (11) in the detection space (m). .

In the case of the apparatus shown in FIG. 2, the nozzle (4) of the air gun (3) is separated by u in front of the reflection type optical detector (1b).
The air jet channel (1) is formed coaxially and formed by jetting an air jet from the nozzle (4) into the detection space (m).
The optical axis (2b) of the reflection type optical detector (1b) is positioned at 0). In this way, the light projection path and the reflection light path of the reflection type optical detector (1b) are formed in the clean air jet flow path (10), and are not affected by floating dust and vapor in the detection space (m). Optical detection is performed.

The optical detecting device of the third embodiment shown in FIG. 3 comprises a radiation type optical detector (1c) and an air gun (3) similar to the above. The radiation type optical detector (1c) receives light (such as infrared light) from the detection target (12) in the detection space (m) of the detection target.

Also in the case of the apparatus shown in FIG. 3, the nozzle (4) of the air gun (3) is arranged coaxially at a distance in front of the radiation type optical detector (c) to detect the air from the nozzle (4). An air jet is jetted into the space (m). Then, the light from the object to be detected (12) is transferred to the clean air jet channel (10) and nozzle (4).
And reaches the optical detector (1c), the optical detector (1c) performs the optical detection operation accurately without being affected by floating dust and vapor in the detection space (m).

[0022]

According to the present invention, even if the space between the optical detector and the object to be inspected is in a non-clean state due to floating dust and vapor, the air injected from the nozzle of the air gun into this space. To form a clean air jet channel,
Since the optical detector operates by passing light through the air jet flow path, it is possible to provide a highly reliable optical detection device whose performance does not deteriorate even in a non-clean environment where dust floats or in a harsh environment where steam flows.

[Brief description of the drawings]

FIG. 1 is a side view of a main part including a partial cross section of an optical detection device showing a first embodiment of the present invention.

FIG. 2 is a side view of a main part including a partial cross section of the optical detection device showing a second embodiment of the present invention.

FIG. 3 is a side view of a main part including a partial cross section of an optical detection device showing a third embodiment of the present invention.

FIG. 4 is a side view of a main part of a conventional optical detection device.

[Explanation of symbols]

 1a Optical detector 1b Optical detector 1c Optical detector 2a Optical axis 2b Optical axis 3 Air gun 4 Nozzle 5 Through hole 7 Air suction port 8 Air discharge port 9 Compressed air 10 Air jet flow path

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Satoru Satoru Miyashita 2-1-1-12 Sonezaki, Kita-ku, Osaka City, Osaka Prefecture Inside Hokuyo Electric Co., Ltd. 63-185532 (JP, U) JP-B 52-22727 (JP, B2)

Claims (1)

(57) [Scope of request for utility model registration] 1. An optical detector for optically detecting a detection target by directing an optical axis to the detection target, and a straight through hole having one end serving as an air suction port and the other end serving as an air discharge port. , Air from the approximate center of this through hole
-Compress the compressed air supplied from the piping toward the discharge hole
It has a nozzle that sprays in an spiral shape.
Outside air sucked from the air suction hole by air flow
And a through-type air gun that merges with the spiral air and jets the jet air from the air discharge hole in the direction of the center line of the through-hole. Align the center line with the optical axis of the optical detector , and
The distance from the optical detector was kept so as not to prevent
An optical detection device which is disposed between an optical detector and a detection target in a state, and an optical axis of the optical detector is positioned in an air jet passage of air jetted from an air gun.