JPH03249242A - Device of optical sensor - Google Patents

Abstract

PURPOSE:To prevent attaching and accumulation of dust, etc., on light-projecting and light-receiving faces by providing vent holes in a storing parts storing a light projector and a light receiver and flowing air flows to outside through the vent holes. CONSTITUTION:Vent holes A1 and B1 are provided in storing parts A and B storing a light projector 21 and a light-receiver 22 and air flows flowing to outside through the vent holes are formed. Dust, etc., in atmosphere is flown to directions separating from light-projecting and light-receiving faces of the light projector and the light receiver to avoid attaching or accumulating on the light-projecting and light receiving faces.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an optical sensor device that can be suitably used for detecting the presence of yarn in textile machines, particularly weaving machines.

Prior Art In textile machinery, highly sensitive optical sensor devices are often used to detect the presence of yarn, especially in weaving machines.
The weft feeler used to monitor whether or not weft insertion has been carried out normally needs to reliably detect the thin weft threads that move violently, and must not only be highly sensitive but also stable and operate at high speed. It is known for.

On the other hand, the operating environment of a textile machine is not necessarily a clean atmosphere, and therefore various efforts have been made to ensure stable operation of the optical sensor device over a long period of time. For example, a technology that attempts to keep the light emitting and light receiving surfaces clean by constantly blowing air on the light emitter and light receiver that form the optical sensor device has been known for a long time (for example, 53-83780
(Japanese Patent Application Laid-Open No. 61-28051). Regarding the weft feeler of the water jet loom, a technology has also been proposed in which air is blown from the emitter side to the receiver side to quickly blow away water droplets adhering to the light receiving surface (Japanese Utility Model Publication No. 54-34069). ).

When the problem to be solved by the invention is based on the former of the prior art, the problem is that the light projection surface,
Air is constantly blown onto the light-receiving surface, so if there are fluff or various types of dust floating in the environment, these fine particles will be blown onto the light-emitting and receiving surface and accumulate.
On the contrary, there was a problem in that the performance of the optical sensor device deteriorated. In addition, when using the latter method, air is blown from the emitter side to the receiver side, so although it may be fine on the emitter side, the same problem as the former occurs on the receiver side, and if the distance between the emitter and receiver is wide. However, since the flow velocity of air at the light receiving surface is reduced, it can only be applied to systems where the distance between the projector and the light receiver is narrow, and the range of application is severely restricted.

Furthermore, in order to achieve the desired effect, it is necessary to ensure a flow rate of air at the light emitting/receiving surface equal to or higher than that of the -chamber, which leads to the problem of high air consumption and uneconomical performance. Ta.

Therefore, in view of the problems of the prior art, an object of the present invention is to form air flows toward the front of both the emitter side and the receiver side, thereby reducing air consumption and making it economical. It is an object of the present invention to provide an optical sensor device which has a wide range of application and is free from any fear of performance deterioration due to accumulation of dust or the like in the atmosphere.

Means for Solving the Problems The structure of the present invention to achieve the object includes a light emitter and a light receiver forming an optical system for detecting an object, and a storage for housing the light emitter and light receiver. The gist is that the storage section is provided with a ventilation hole corresponding to the optical axis from the projector, and that an air flow is formed from the storage section to the outside through the ventilation hole.

Note that the storage portion may be formed independently for the projector and the light receiver, or may be formed in common.

Furthermore, the direction of the central axis of the ventilation hole can be different from the direction of the optical axis.

Effects According to the structure of the invention, the storage section is provided with a ventilation hole, and an air flow directed to the outside is formed through the ventilation hole. These dust particles are blown away by the air flow in a direction away from the light emitting/receiving surfaces of the light emitter or light receiver, and can be effectively prevented from adhering to or accumulating on the light emitting/receiving surfaces.

Further, since the air flow at this time is sufficient to simply blow away floating dust, etc., an extremely small flow velocity is sufficient.

Note that the storage section may be provided independently or in common with the projector and the light receiver, and in either case, it is convenient to provide a common connection boat with the air source.

By setting the center axis of the ventilation hole and the optical axis in different directions, mutual interference between the air flow blown from the emitter side and the air flow blown out from the receiver side can be avoided, and this is useful when the distance between the emitter and receiver is narrow. However, there is no heat haze phenomenon caused by turbulence in the airflow, and there is no risk that the operation of the light receiver will become unstable due to this.

Example Examples will be described below with reference to the drawings.

The optical sensor device includes a holder 10, a light emitter 21, and a light receiver 2.
2 (Figures 1 and 2). However, here:
The optical sensor device is attached to the front of a drum-type weft length measuring and storage device (hereinafter referred to as storage device) D of the loom, and is used to monitor the yarn that is unwound from the storage device and pulled out forward (in the direction of the arrow in Figure 2). It is used as an unwinding sensor to detect Y.

The storage device includes split drums D1, DI..., a rotating yarn guide D2, a motor D3, and a locking pin D4. By driving the motor D3 and rotating the rotary yarn guide D2, the thread Y that has been drawn through can be wound around the outer periphery of the drums DI, Dl, and stored. On the other hand, the locking pin D4 includes a pin (not shown) that moves forward and backward with respect to the outer periphery of the drum D1, so if this pin is advanced in the direction of the drum DI, the thread Y will move toward the drum D1.
, Dl... can be prevented from being unraveled,
This can be tolerated by retracting the pin.

The unwinding sensor detects the yarn Y being unwound while drawing a balloon from the drums DI, Di, etc., and is used to detect the unwound length of the yarn Y. That is, after allowing the thread Y to unwind by retracting the locking pin D4 to the unwinding position, the unwinding sensor detects that a predetermined number of turns of the thread Y has been unwound, and the pin is locked. If you advance it to the position,
Thread Y of the length required for one weft insertion is transferred to drums D1, Dl.
It can be unraveled accurately from... Incidentally, if the winding direction of the yarn Y by the rotating yarn guide D2 is one direction as shown by the arrow in FIG. 2, the rotation direction of the balloon created by the yarn Y during unwinding will also be two directions as shown by the arrow in the same figure.

The holder 10 of the optical sensor device has a main body 11 in the shape of a horseshoe.
A mounting portion 12 is provided protruding from the main body portion 11, and a light emitter 21 and a light receiver 22 are attached to each tip of both legs of the main body portion 11.

The light emitter 21 and the light receiver 22 are fixed so as to face each other, and the optical axis from the light emitting surface of the former is incident on the light receiving surface of the latter, thereby forming an optical system that detects the thread Y. . That is, when the thread Y crosses the optical axis, the amount of light incident on the light receiver 22 decreases, and the output signal of the light receiver 22 changes, so that the presence of the thread Y can be detected.

The front side of the projector 21 is covered with a cover plate 13 (FIGS. 1 and 3). The cover plate 13 is fixed to the main body 11 via a gasket 13b, and a floodlight 2 is provided on the inner surface of the cover plate 13.
1 is formed, and the storage part A has a ventilation hole Al opened therein. The ventilation hole A1 is provided corresponding to the optical axis from the floodlight 21,
Therefore, the optical axis can be emitted to the outside through the ventilation hole A1. In addition, the floodlight 21
A mounting seat for the projector 21 is formed at the rear of the projector 21.
A recess 11a is formed for drawing out the lead wire from the recess 11a.

The light receiver 22 is mounted in the same manner as the light projector 21. That is, the front surface of the light receiver 22 is covered by a cover plate 14 with a ventilation hole Bl, and a storage section B for storing the light receiver 22 is formed on the inner surface of the cover plate 14. The cover plate 14 is fixed via a gasket 14b, and a recess 11b is formed at the rear of the light receiver 22. The ventilation hole B1 is provided corresponding to the position where the optical axis enters the light receiver 22, and its opening area is
In consideration of diffusion along the optical axis, it is formed slightly larger than the ventilation hole A1.

An air passage 11c is formed inside the main body part 11 and communicates with the storage parts A and B (FIGS. 1 and 3). However, for convenience in machining, the air passage 11c is formed by combining a plurality of straight paths, and the opening to the outside of the main body 11 is closed by plugs 11d, 11d, . . . .

The main body portion 11 is provided with a connection port 11e that communicates with the air passage 11c, and an air hose H can be connected to the connection port lie via a nipple H1 to connect to an air source (not shown).

The mounting portion 12 is provided with a cavity 12a inside, and an amplifier unit (not shown) or the like can be housed in the cavity 12a, and the cavity 12a is closed by a lid 12b. Further, the entire optical sensor device can be attached to the front surface of the locking pin D4 of the storage device using the attachment portion 12.

Now, when air is introduced into the connection port 11e via the air hose H, the air flows into the storage section A via the air passage 11c.
, B, and flows out through ventilation holes Al and Bl. The air flow at this time flows from the rear to the front inside the storage units A and B, wrapping around the light emitting and receiving surfaces at the tips of the emitter 21 and the receiver 22, and finally flows through the ventilation holes Al. , Bl to the outside. Therefore, even if dust or the like is floating in the external use atmosphere, there is no possibility that the dust or the like will enter the interior of the housing sections A and B or adhere to the light emitting/receiving surfaces.

In addition, since the air flow flowing out from the ventilation holes Al and Bl in this way is to prevent floating dust etc. from entering the storage part A1B, the flow velocity only needs to be small; Only a small amount of air is consumed. Although it is preferable to keep this air flow flowing all the time, for example, only when performing a detection operation for the thread Y,
It is practically sufficient to stop the air flow and allow it to flow intermittently, and in this case, the air flow supply/cutoff operation can be synchronized with the timing of the operation of the locking pin D4, for example.

Other embodiments of the optical sensor device may use a ring-shaped holder 1o attached to the front surface of the locking pin D4 (FIGS. 4 and 5).
. The holder lO is formed by screwing a ring-shaped cover plate 16 onto one side of a ring-shaped main body 15 via screws 16a, and the main body 15 has an air passage 15a1 concentrically formed therein. A wire passage 15b is formed (FIG. 5).

The light emitter 21 and the light receiver 22 are attached to the main body 15 so as to face each other, and the main body 15 is formed with storage parts A and B that accommodate the light emitter 21 and the light receiver 22. Storage sections A and B have ventilation holes Al and B, respectively, at positions corresponding to the optical axis.
1 and communicated via an air passage 15a,
Furthermore, a connection port 15c for connecting the air hose H is formed in a part thereof. Since the overall shape is ring-shaped, machining is not only easy (but also when attaching the balloon breaker to the front of the storage device,
It is convenient because it can also serve as the mounting base.

The ventilation holes Al and Bl have their central axes A2 with respect to the optical axis.
, B2 can be tilted (Fig. 6). Since the central axes A2 and B2 have angles θa and θb with respect to the optical axis, even when the distance d between the emitter 21 and the receiver 22 is small, the air flow flowing out from the ventilation hole ASB does not interfere with the optical axis. , the output signal of the light receiver 22 will not become unstable due to the haze phenomenon.

The light projector 21 and the light receiver 22 can also form a reflective optical sensor device (FIG. 7). Here, air passage 1
By tilting and attaching the auxiliary member 18.18 to the main body 17 having the shape 7a, an optical system from the light projector 21 to the light receiver 22 via an arbitrary object P is completed, and the auxiliary member 18.18 Storage parts A and B with ventilation holes AI and Bl communicating with the air passage 17a are formed in the storage parts A and B.

The storage part A may be formed inside the main body part 19 and shared by the light projector 21 and the light receiver 22 (FIG. 8).

The light from the projector 21 passes through the half mirror 23 and reaches the object P, and is reflected by the object P and the half mirror 23 to form an optical system that reaches the light receiver 22, and as a whole, a reflective optical sensor is formed. It forms a device.

Note that the present invention can be applied to cases where the projector 21 and the light receiver 22 form either a transmission type or a reflection type optical sensor device, and the detection object is not limited to the thread Y. It can be anything. In addition, storage section A,
B may be provided independently for the light projector 21 and the light receiver 22, or may be provided in common.

As described in detail, according to the present invention, a ventilation hole is provided in the storage part that houses the projector and the light receiver, and the air flow is caused to flow outside through the ventilation hole. ,
Since it is possible to effectively prevent dust from adhering to and accumulating on the light emitting and receiving surfaces of the emitter and receiver, it is possible to effectively eliminate the risk of performance deterioration. It is sufficient to blow the air away, so an extremely small flow velocity is sufficient. Therefore, it is not only economical with low air consumption, but also suitable for all kinds of applications, including cases where the distance between the emitter and receiver is wide. It has the excellent effect of being able to

[Brief explanation of the drawings] Figures 1 to 3 show an embodiment, Figure 1 is an explanatory diagram of the overall configuration, Figure 2 is a perspective diagram of the usage state, and Figure 3 is an enlarged view of the main parts of Figure 1. It is a diagram. 4 and 5 show other embodiments, FIG. 4 is a diagram corresponding to FIG. 2, and FIG. 5 (A) or C) is the x-xSy-ySz-z arrow in FIG. FIG. FIGS. 6 to 8 show the first embodiment showing different embodiments, respectively.
It is a figure equivalent figure. P...object L...optical axis A, B...storage section Al, Bl...ventilation hole A2, B2...center axis 10...holder 21...emitter 22...light receiving timely applicant

Claims (1)

[Scope of Claims] 1) Consisting of a light projector and a light receiver forming an optical system for detecting an object, and a holder including a storage section for storing the light projector and the light receiver, the storage section comprising: An optical sensor device comprising a ventilation hole corresponding to the optical axis from the light projector, and forming an air flow outward from the storage section through the ventilation hole. 2) The optical sensor device according to claim 1, wherein the storage section is formed independently of the light emitter and the light receiver. 3) The optical sensor device according to claim 1, wherein the storage section is formed commonly for the light projector and the light receiver. 4) The optical sensor device according to any one of claims 1 to 3, wherein the direction of the central axis of the ventilation hole is different from the direction of the optical axis.