JP2796384B2 - Unwinding sensor for drum type weft length storage device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an unwinding sensor of a drum type weft length measuring and storing device for measuring the length of a weft unwound from a drum and inserted.

2. Description of the Related Art In a shuttleless loom including a jet loom, a drum type weft length measuring and storing device (hereinafter, simply referred to as a length measuring device) is widely used to control the length of a weft inserted into a specified value. .

The length measuring device includes a stationary drum type and a rotating drum type, and the former is more general. Since the rotating yarn guides the winding and storage of the weft around the drum, high-speed performance is easy to achieve, and a fixed locking pin is arranged outside the drum to easily control the unwinding and locking of the weft. Because you can.

Control of the locking pin is generally performed by an unwind sensor. That is, at a predetermined unwinding time, after the locking pin is driven to the unwinding position to start the weft insertion, it is detected by the unwinding sensor that a predetermined number of turns of the weft yarn has been unwound from the drum. May be driven to the locking position. At this time, the locking pin is considered in consideration of the response time of the locking pin so that the timing when the locking pin actually reaches the locking position is the optimum position with respect to the weft being unwound in the final turn. The installation position of the unwind sensor must be determined.
If the response time of the locking pin is not negligible with respect to the unwinding time of one turn of the weft unwound from the drum, for example, the number of turns of the weft is one less than the predetermined number of turns. In this case, a lock signal may be sent to the lock pin, and special consideration may be given to maintain coordination between the response time of the lock pin and the unwinding time for one turn. Not a few.

There are a reflection type and a transmission type optical sensor as an unwinding sensor used for such an application. Generally, the latter has a wider adaptability to the type and color of the weft yarn.

Problems to be Solved by the Invention According to such a conventional technique, the unwinding sensor generally takes into account the unwinding direction of the weft in order to measure the length of the weft unwound from the drum as accurately as possible. It must be arranged at a predetermined position with respect to the locking pin, for example, immediately downstream of the locking pin. On the other hand, the unwinding direction of the weft depends on the twisting direction of the weft, but the conventional unwinding sensor is of a fixed type. There is no other choice but to provide one set for each twisting direction or to use one unwinding sensor for wefts in different twisting directions. That is, according to the former, two sets of unwinding sensors are required, and it is necessary to select the unwinding sensors according to the twisting direction. Therefore, the entire structure is complicated, which is uneconomical, and the selection operation is troublesome. Also, according to the latter, even if it is good for one twist direction,
A large measurement error may occur in the other twist direction.

Accordingly, an object of the present invention is to provide a light emitting device and a light receiving device of a set of unwinding sensors equidistant to the left and right of a locking pin in view of the situation of the related art, so that the overall structure is simple and economical. It is an object of the present invention to provide an unwinding sensor of a drum type weft length measuring and storing device which is not likely to cause an excessive measurement error.

Means for Solving the Problems The configuration of the present invention for achieving such an object is provided opposite to each other on the front surface of the drum, and includes a light emitter and a light receiver for detecting a weft unwound from the drum, The gist of the invention is that the light emitter and the light receiver are arranged at the same distance from the locking pin in the circumferential direction of the drum.

The light emitter and the light receiver may be disposed on the diameter of the drum orthogonal to the locking pin, or may be mounted on a sensor bracket that also serves as a mounting seat of the balloon breaker.

According to the configuration of the invention, the projector and the receiver are
Since the optical axis forms a transmission type unwinding sensor that traverses the front surface of the drum, two unwinding signals can be obtained from the light receiver every time one turn of the weft is unwound. Also, floodlights,
Since the receiver is arranged at the same distance from the locking pin in the circumferential direction of the drum, even if the twisting direction of the weft is changed and the unwinding direction of the weft from the drum is reversed, The relative time relationship between the output timing of the unwinding signal output from the container and the timing at which the unwound weft passes the position of the locking pin is completely unchanged. Therefore, the control device that drives the locking pin to the locking position using the unwind signal only needs to provide a single control circuit, and does not require any special switching operation or the like.

If the light emitter and the light receiver are arranged on the diameter of the drum, the unwinding signals output two by one per turn will be pulse trains at equal intervals regardless of the twist direction of the weft, and the processing of the unwinding signal will be further improved. Easy.

If a light emitter and a light receiver are mounted on the sensor bracket that also serves as the mounting seat of the balloon breaker, it is convenient when installing the balloon breaker in front of the drum, and furthermore, by incorporating a head amplifier in the sensor bracket,
More stable operation can be realized.

Embodiments Hereinafter, embodiments will be described with reference to the drawings.

The unwinding sensor 10 of the drum type weft measuring and storing device is a floodlight
11 and a light receiver 12 (FIG. 1), which is mounted on the front face of the drum D1 of the length measuring device D.

The length measuring device D includes a drum D1 and a weft Y on the peripheral surface of the drum D1.
And a motor D3 for driving the rotary yarn guide D2, and a locking pin which advances and retreats with respect to the peripheral surface of the drum D1, locks and releases the weft Y on the drum D1. With D4. The weft Y is supplied from a yarn feeder Y1 behind the motor D3, is drawn through a yarn passage (not shown) formed in the axis of the motor D3 to the tip of a hollow rotary yarn guide D2, and passes through the rotary yarn guide D2. By being driven to rotate, it is wound and stored on the peripheral surface of the drum D1. The locking pin D4 locks the weft Y on the drum D1 at a locking position where the leading end protrudes into the circumferential surface of the drum D1, and prevents the unwinding of the weft Y, while unwinding from the circumferential surface of the drum D1. At the position, the unwinding of the weft Y from the drum D1 is permitted, and the weft insertion nozzle N
Weft insertion can be performed via the.

The locking pin D4 is electrically driven by an electromagnetic solenoid. The locking pin D4 is driven to the unwinding position by a drive signal Sk from the control device S. The control device S corresponds to the loom mechanical angle θ from the encoder EN, and outputs a drive signal at a predetermined weft insertion time. Output Sk. Further, since the unwinding signal Si from the light receiver 12 is input to the control device S, the control device S performs a predetermined driving so that the weft Y having a predetermined number of turns is accurately unwound from the drum D1. The signal Sk is reset, the locking pin D4 is returned to the locking position, and the unwinding of the weft Y can be stopped.

The light emitter 11 and the light receiver 12 are attached by a ring-shaped sensor bracket B1 attached to the front of the drum D1.
The sensor bracket B1 is also used as a mounting seat for the balloon breaker B. That is, the sensor bracket B1
Has an inner diameter slightly larger than that of the drum D1, and a base of a balloon breaker B having a hollow truncated cone shape is fixed to the front surface thereof.

The light emitter 11 and the light receiver 12 are arranged on the sensor bracket B1 regardless of the schematic representation of FIG.
Mounted on top (FIG. 2). However, the diameter d1
Is perpendicular to the diameter d2 of the drum D1 passing through the position where the locking pin D4 is provided. The light emitter 11 and the light receiver 12 form a transmission type unwinding sensor 10 having an optical axis crossing the center of the drum D1 on the front surface.

The unwinding sensor 10 having such a configuration can measure the length of the weft Y unwound from the drum D1 in units of 1/2 turn of the drum D1. Weft Y unwound from drum D1
Forms a balloon that rotates in the unwinding direction on the front surface of the drum D1, and includes an unwinding sensor
Because it crosses the optical axis every 1/2 turn.

The distances a1 and a2 between the emitter 11, the receiver 12 and the locking pin D4 are:
A1 = a2 = L / 4 in the circumferential direction of the drum D1 (where L is the drum D
1 circumference). Therefore, even if the twist direction of the weft Y is changed and the unwinding direction of the weft Y from the drum D1 is reversed,
The unwinding signal Si from the light receiver 12 is a pulse train with exactly the same pulse interval. That is, even if the twisting direction of the weft Y is changed, no special switching operation or the like is required, and the control device S only needs to include a single signal processing circuit.

In the above description, the projector 11 and the receiver 12 have the diameter d1.
May be arranged on an arbitrary straight line d3 parallel to (a two-dot chain line in FIG. 2). Also at this time, the transmitter 11, the receiver 12, and the locking pin
The distances a1 and a2 from D4 are maintained at a1 = a2, and the relative time relationship between the time when the weft Y unwound from the drum D1 passes through the locking pin D4 and the output time of the unwind signal Si is as follows: It is constant regardless of the twisting direction of the weft Y.

The light emitter 11 and the light receiver 12 may be mounted on a dedicated sensor bracket separate from the mounting seat of the balloon breaker B. Note that the balloon breaker B may be attached as needed, and may be omitted. Further, a head amplifier that amplifies the unwinding signal Si from the light receiver 12 can be incorporated in these sensor brackets including the sensor bracket B1. Since it is not necessary to transmit a weak signal over a long distance, a stable operation can be realized.

Effect of the Invention As described above, according to the present invention, by arranging the light emitter and the light receiver at the same distance in the circumferential direction of the drum with respect to the locking pin, the light receiver can be moved in the weft unwinding direction. Regardless, since the unwinding signal can be generated in a fixed relative time relationship from the time when the weft passes the position of the locking pin, even if the twist direction of the weft is changed, There is no need to provide a special unwinding sensor in the direction or perform a special switching operation, so that the overall structure is significantly simplified, and there is an excellent effect that there is no risk of causing a harmful measurement error.

[Brief description of the drawings]

1 and 2 show an embodiment, FIG. 1 is an explanatory view of a use state, and FIG. 2 is a schematic explanatory view corresponding to the line XX of FIG. Y: Weft D: Drum type weft measuring and storing device D1: Drum d1: Diameter D4: Locking pin B: Balloon breaker B1: Sensor bracket 10: Unwinding sensor 11: Emitter 12 ... … Receiver

Claims (3)

(57) [Claims] 1. A light emitting device comprising: a light emitter and a light receiver which are provided on a front surface of a drum so as to face each other and detect a weft unwound from the drum; An unwinding sensor for a drum type weft length measuring and storing device, wherein the unwinding sensor is disposed at an equal distance in a direction. 2. The unwinding sensor for a drum type weft length measuring and storing device according to claim 1, wherein said light emitter and said light receiver are arranged on a diameter of a drum orthogonal to a locking pin. 3. A solution for a drum type weft length measuring and storing device according to claim 1, wherein said light transmitter and said light receiver are mounted on a sensor bracket which also functions as a mounting seat of a balloon breaker. Shu sensor.