JPH0447061B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement of a weft feeler for a loom, and an object thereof is to provide a weft feeler with high weft detection accuracy.

[Conventional technology and technical issues to be solved]

As is well known, in a fluid jet type shuttleless loom, it is checked whether the weft thread is properly inserted between the weft threads opened at each pick by the held operation, and if an abnormality occurs, the operation is stopped. A weft filler is required as a control means.

Conventionally, there are two types of weft fillers used as such control means: those belonging to mechanical systems and those belonging to optical systems. However, mechanical systems are unavoidably affected by inertial resistance, and are not suitable for modern high-speed looms. Since it is not possible to accurately follow the weft filler, optical weft fillers, which are advantageous in terms of followability, have recently been viewed as promising.

However, with optical systems, a search signal is obtained by irradiating a search light onto the flight path of the weft yarn and using a photoelectric element to respond to changes in the amount of reflected light, which increases or decreases depending on the presence or absence of the weft yarn in the flight path under irradiation. Since this method is adopted, the problem is how to accurately detect changes in the amount of reflected light, or how to make changes in the amount of light large enough to be easily detected.

Previously, Special Publication No. 54-24501 and Utility Publication No. 11262-1983
No. 57-117651, etc., have been proposed, and attempts have been made to reliably detect changes in the amount of light due to weft insertion. Among these, JP-B No. 54-24501 uses a lens to convert the light from a light source into parallel beams, and sends the reflected light from the irradiated surface back to the receiver using an optical fiber. However, due to the design of the loom, the light source Since it is necessary to keep a considerable distance between the search beam and the flight path irradiation surface, there is a drawback that the brightness of the search light irradiated is not sufficient even if the light is focused by a lens.
In addition, optical fibers have the disadvantage that there is a limit to the size of the light-receiving surface, and there is a limit to the amount of reflected light that can be received and transmitted. Also, Jikko 61-
In No. 11262, the light is emitted directly from the light source, and the reflected light is focused by a lens and guided to the receiver.
As expected, there was a drawback that the amount of search light was insufficient due to the distance between the light source and the irradiation surface, and Japanese Patent Application Laid-Open No. 117651/1983 transmitted the search light using an optical fiber and reflected light. The item will be returned using optical fiber, and since the optical fiber for irradiating the search light and the optical fiber for receiving the reflected light must be placed in front of the irradiation surface, the irradiation surface of the optical fiber for irradiation must also be placed in front of the irradiation surface. The area of the light-receiving surface of the optical fiber for light-receiving has also become smaller, resulting in the disadvantage that less reflected light can be received by the light receiver.

The present invention was made in view of the above-mentioned problems with conventional weft fillers, and a technical object of the present invention is to provide an optical search type weft filler with higher detection accuracy.

[Means adopted to solve the problem]

In the present invention, the means adopted to solve the above problem are as follows.

That is, according to the present invention, it is a densely packed body of a large number of optical fibers, which transmits search light generated by a light projecting source disposed on one end face, and spreads a planar shape toward a target from the other end face. an optical transmission means for projecting light onto the weft thread to form a clear search area of a certain range on the weft flight path; A cylinder lens collects reflected light that increases or decreases depending on the presence or absence of a weft in the search/exploration area, and outputs a weft entry search signal in response to changes in the amount of light while sensing the focused light. A weft filler is provided, characterized in that it includes a weft entry detection means.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described below with reference to illustrated embodiments.

FIG. 1 is a perspective view showing the entire reflection type weft feeler constructed using the principle of the present invention, in which a weft entry detection means 1 (to be described later) is placed on the weft flight path in front of the reed 2 on which the weft W runs. They are located opposite each other. One end face 3a, 3a of a light transmitting means 3 made of a dense bundle of optical fibers branching from a light source 4 into two branches is arranged on both sides of the weft-in exploration means 1. These end faces 3a, 3a are locations where a light beam generated by a light projection source 4 (using a semiconductor laser) disposed on the opposite end face is projected parallel to the front of the exploration means 1 as search light. A clear search area S of a corresponding area is clearly formed in front of the search means 1 of the weft flying path with a large illuminance difference. In the figure, 5 is an amplifier, 6 is a cam switch driven in synchronization with the main shaft of the loom, 7 is a comparator, 8 is a threshold value setter, and 9 is a stop signal generator.

The weft entry detection signal output from the weft entry detection means 1 is input to the amplifier 5, and the detection signal amplified by the amplifier 5 is sent to the comparator 7 at a predetermined timing via the cam switch 6. is input. The comparator 7 compares the threshold value input signal from the threshold value setter 8 with the detection signal intermittently input from the cam switch 6, and when the potential of the detection signal is lower than the threshold input signal, The loom is stopped by issuing an abnormal weft entry signal and activating the stop signal generator 9.

In the present invention, as shown in FIG. 2, the search light is transmitted by the light transmission means 3 and only searches the necessary minimum flying path range with respect to the light projection end surface 3a. The ratio (Ls/Ls+Ln) of the amount of feedback light Ls that hits and is reflected to the amount of other reflected light Ln that becomes noise becomes relatively large. In addition, since the search light from the light projection end face 3a has many parallel light components, it is highly dense and highly directional, and the search light may be diffused in an unnecessary direction, lowering the signal potential, or the direction of the diffused light may be Malfunctions do not occur due to the so-called fog phenomenon caused by direct incidence on the input probe 1. Therefore, within the search area that corresponds to the clear search area S, the light amount change Ls corresponding to the presence or absence of the weft yarn can be accurately detected by the weft insertion search means 1.
As a result, the weft detection accuracy is dramatically improved.

Further, a mechanism for concretely realizing correspondence between the exploration area of the weft entry exploration means 1 and the clear search area formed by the optical transmission means 3 is shown in FIG.

First, the weft entry exploration means 1 includes a cylinder lens 10 and a light receiving element (for example, a photodiode, a photocell, etc.) that produces a photoelectric effect in response to an increase or decrease in return search light from a search area. On the other hand, the light projected in parallel from the light projection end surface 3a of the light transmission means 3 forms a high-concentration clear search area in front of the weft entry search means 1. A cylinder lens 10 is interposed between the cylinder lens 10 and the focal length of the cylinder lens 10 so as to cover the search area S, so that the return search light from the search area does not leak. They will be arrested.

Furthermore, various configurations can be adopted for the arrangement of the weft entry exploration means 1 and the optical transmission means 3, as shown in FIGS. 3a to 3d. In the arrangement example shown in FIG. 3a, the optical fiber is inserted between the cylinder lenses 10 divided into two in the direction perpendicular to the focal line, and in the example shown in FIGS. The end face 3a of the optical fiber is inserted into the cylinder lens 10 which is bored in the cylinder lens 10. In FIG. 3b, the optical fibers are arranged so as to surround the cylinder lens 10, and irradiate the search surface with search light from four directions.

Although the present invention has been described above based on Examples, the present invention is not limited to the above-mentioned Examples, and various changes can be made without departing from the gist of the present invention.

First, regarding the light source 4, a semiconductor laser such as a GaAs diode is advantageous for miniaturization.
In the present invention, since the optical fiber dense body is used as the light transmission means, it is possible to freely select the installation location of the light source.

[Effects of the present invention]

As described above, according to the present invention, optical
It is now possible to effectively guide and irradiate the search light to the required area using fibers, and no matter where the light source is located, it is possible to identify the presence or absence of weft threads by irradiating the strong search light. It became like that. Furthermore, by receiving all reflected light with a cylinder lens with a large light-receiving area, it has become possible to reliably detect changes in the amount of reflected light due to the presence or absence of weft threads.

As described above, the weft feeler of the present invention has high weft detection accuracy and is extremely useful industrially.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the entire reflected light receiving type weft filler to which the principle of the present invention is applied, Fig. 2 is a front view showing the operating principle of the present invention, and Fig. 3 a, b, c, d.
4 is an explanatory diagram of the arrangement of the weft entry exploration means and the optical transmission means, and FIG. 4 is a perspective view schematically showing the matching relationship between the clear search area formed by the optical transmission means and the exploration area possessed by the weft entry exploration means. It is an explanatory diagram. 1... Weft entry exploration means, 3... Optical transmission means, 4... Light projection source.

Claims (1)

[Scope of Claims] 1. A densely packed body of a large number of optical fibers, which transmits search light generated by a light projecting source placed on one end surface and spreads it planarly toward a target from the other end surface. A light transmission means for projecting light to form a clear search area of a certain range on the weft flight path; having a search area on the weft flight path that corresponds to the clear search area formed by this light transmission means, and that corresponds to the clear search area formed by the light transmission means; A cylinder lens collects the reflected light, which increases or decreases depending on the presence or absence of weft threads in the search/exploration area, and while sensing the collected reflected light, weft insertion is performed in response to changes in the amount of reflected light. 1. A weft feeler comprising: a weft entry probe for outputting a probe signal. 2 Claim 1 in which a laser is used as the light projection source
Weft filler as described. 3. Claim 1, wherein the light emitting end face of the light transmission means is disposed on a side surface of the weft entry detection means parallel to the weft flight path.
Or the weft filler according to 2.