JPH08174543A - Method and apparatus for detecting presence of charged raw material in twin-screw meshing type taper screw feeder - Google Patents

Abstract

PURPOSE: To detect the presence of the raw material in a hopper in order to automatically charge a rubbery resin raw material in the hopper of a conical feeder being a twin-screw meshing type taper screw feeder. CONSTITUTION: An ultrasonic displacement sensor 10 detecting the displacement level of the downstream part of the screw 2 in the hopper 4 of a conical feeder 1 is attached to the upper part of the hopper 4 to detect the displacement level of the downstream part of the screw 2 in the hopper 4 and the displacement level is used to detect the presence of a charged raw material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for detecting the presence or absence of input material in a twin-screw mesh type taper screw feeder used for supplying a rubber-based resin material such as an elastomer to a kneading extruder.

[0002]

2. Description of the Related Art Normally, a rubber-based resin raw material (resin raw material) such as an elastomer is approximately
The shape of 500 mm square × 500 mm L is common, and finally,
It is supplied to a kneading extruder or the like, kneaded and molded, and then used. 2 in order to supply the resin raw material to the kneading extruder
A conical feeder as a shaft meshing type taper screw feeder is provided, and the resin raw material is kneaded into the kneading extruder while kneading the resin raw material with this conical feeder.

[0003]

In order to continuously and continuously supply the resin raw material to the kneading extruder with the above-mentioned conical feeder, it is necessary to detect the presence or absence of the resin raw material. Since it is about 500 mm square × 500 mm L,
The situation in which it is cut into the screw and supplied is not uniform,
It was difficult to detect the remaining level.

That is, since a resin raw material having a size of about 500 mm square × 500 mm L (weight of about 130 KG) is put into the hopper of the conical feeder, the next resin is detected after the displacement level becomes low. It is necessary to add raw materials. However, since the resin raw material is sent to the downstream side while being kneaded in the tapered screw, it becomes a dumpling or a band depending on the screw part or the biting condition, so the displacement level is a normal level. It could not be detected by the sensor, and the operator had to judge the presence or absence of the resin raw material while directly monitoring the resin raw material in the hopper or on the TV monitor, and injected the resin raw material.

The present invention has been made in view of the above problems of the prior art. The object of the present invention is to automatically supply a rubber-based resin raw material to a hopper of a biaxial meshing taper screw feeder. The present invention is to provide a detection method and an apparatus for detecting the presence or absence of the input material in the hopper for the purpose of inputting the material.

[0006]

A method for detecting the presence or absence of a feed material in a twin-shaft mesh type taper screw feeder according to the present invention is such that an ultrasonic displacement sensor is attached to an upper part of a hopper and a downstream portion of the screw in the hopper is displaced. In this method, the level is detected and the presence or absence of the input raw material is detected using the displacement signal.

More specifically, the displacement signal detected by the ultrasonic displacement sensor is amplified by an amplifier and input to one of the comparators, and the comparator compares it with the level signal from the level setter. In this method, a timer start signal is input to the timer and a time-up signal is output when it does not rise above the level signal.

More specifically, the displacement signal detected by the ultrasonic displacement sensor is amplified by an amplifier, input to one of the comparators via a signal processor, and compared with the level signal from the level setter by the comparator. , It is a method to output a signal when it becomes lower than that.

The apparatus for detecting the presence or absence of the charged raw material in the biaxial meshing taper screw feeder according to the present invention is such that an ultrasonic displacement sensor for detecting the displacement level of the downstream portion of the screw in the hopper is attached to the upper part of the hopper. It has a feature.

More specifically, an amplifier for amplifying the displacement signal detected by the ultrasonic displacement sensor, a recorder for recording the amplified signal, a level setter, and the amplified signal and the level setter It is composed of a comparator that compares signals and a timer that starts timing with the signal from the comparator and outputs the signal.

More specifically, an amplifier for amplifying the displacement signal detected by the ultrasonic displacement sensor, a recorder for recording the amplified signal, a signal processor for processing the amplified signal, and a level setting device. And a comparator for comparing the signals from the signal processor and the level setting device and outputting the signals.

The signal processor is preferably an average calculator or a low frequency filter.

[0013]

[Operation] The displacement level of the downstream part of the screw in the hopper is detected by the ultrasonic displacement sensor attached to the upper part of the hopper of the biaxial mesh type taper screw feeder, and the presence or absence of the input material is detected using the displacement signal. To do.

[0014]

EXAMPLES Examples will be described with reference to the drawings. 1 is an overall configuration diagram showing a conical feeder.
1A is a plan view, and FIG. 1B is a front view.

As shown in FIG. 1, a conical feeder 1 as a biaxial meshing taper screw feeder is
A cylinder 3 in which two tapered screws 2 are rotatably inserted, a hopper 4 arranged above the cylinder 3, and a motor 6 for driving the screw 2 via a speed reducer 5.
It is composed of a pedestal 7 that supports the cylinder 3 and the like. The screw 2 is provided with a screw flight 2a having a similarly tapered outer diameter in the longitudinal direction of the outer peripheral wall of a tapered screw shaft having a large diameter in the upstream portion and a small diameter in the downstream portion. It is configured. FIG.
(B) shows a state where the amount of resin raw material is low.

A column 8 is provided at the rear of the speed reducer 5, and an ultrasonic displacement sensor 10 is attached to the tip of the column 8 so as to be located above the hopper 4. The ultrasonic displacement sensor 10 detects the level of the resin raw material in the screw 2 from the hopper 4, and has a detection distance of about 160 cm.

As shown in FIG. 1B, the displacement signal detected by the ultrasonic displacement sensor 10 is amplified by the amplifier 11 and recorded as a displacement level in the recorder 12, and at the same time, for example, a timer in the amplifier 11 is used. The presence or absence of the resin raw material can be detected by extracting a signal through a function or a timer 13 provided outside.
The details will be described later.

Since the resin raw material charged into the hopper is kneaded by the tapered screw 2 and sent to the downstream side, it may have a dumpling shape or a band shape depending on the screw 2 portion or the biting condition. The displacement level is not constant. However, the most downstream portion of the screw flight 2a in the hopper 4 corresponds to the discharge portion, so that the resin raw material is attached to the screw flight 2a and is sent.
The displacement level is relatively stable.

2 and 3 show the results of the implementation of detecting the displacement level of the screw 2 depending on the location. In addition, this implementation example was conducted under the following conditions. Screw large diameter 300 mm, small diameter 170 mm, cylinder discharge port inner diameter 150 mm, motor horsepower 15 k
w, raw material input about 15kg, screw speed 7r.pm.

FIG. 2 shows the displacement level of the downstream portion of the screw 2 in the hopper 4. As shown in the figure, in the empty state, it shows the vicinity of 135 cm which is the valley of the screw 2. When the raw material is put in, the resin raw material is sent while being rolled up in the screw 2, so the length is 85 to 135 cm.

FIG. 3 shows the displacement level of the central portion of the screw 2 in the hopper 4. As shown in the figure, in the empty state, it shows the vicinity of 120 cm which is the valley of the screw 2. It shows that when the raw material is charged, the feed state of the resin raw material fluctuates greatly and is difficult to detect.

From the above-described results, it has been found that the ultrasonic displacement sensor 10 can be used to detect the displacement level of the resin raw material in the hopper 4 at the downstream portion of the screw 2 in the hopper 4.

Next, a method of detecting the presence / absence of the resin raw material by the displacement signal detected by the ultrasonic displacement sensor 10 will be described.

In the method shown in FIG. 4, the sensor 1
The displacement signal detected by 0 is amplified by the amplifier 11 and input to one of the comparators 14. Here, it is compared with the level signal from the level setter 15, and if it is less than that, the timer start signal is input to the timer 13. The timer 13 starts the time measurement, and continues the time measurement unless the level signal exceeds the level signal even once, and outputs a time-up signal, that is, a signal indicating no resin raw material.

In the method shown in FIG. 5, the sensor 1
The displacement signal detected by 0 is amplified by the amplifier 11 and input to one of the comparators 14 via the signal processor 16. Here, it is compared with the level signal from the level setter 15, and if it is lower than that, a signal indicating that there is no resin material is output.

As the signal processor 16, the following can be used. An average calculation (moving average). At the time of averaging, the calculation time becomes a problem, but since the approximate cycle of the signal appearing due to the relationship between the screw flight and the valley is about 1 Hz, 10 to 20 to 30 (seconds) is divided into several parts.
It is divided into several tens and averaged (that is, data is taken at intervals of 1 to 2 (seconds) as 10 divisions). Then, the average value is input to one of the comparators. Low-frequency filter (low-pass filter) In consideration of the above-mentioned frequency, a signal having a frequency of about 1 Hz or higher is cut and input to one of the comparators.

[0027]

Since the present invention is constructed as described above, it has the following effects. That is, since it is possible to detect the presence or absence of the rubber-based resin raw material in the hopper of the biaxial meshing taper screw feeder, the rubber-based resin raw material can be automatically fed into the hopper of the feeder. .

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing a conical feeder, FIG. 1 (a) is a plan view, and FIG. 1 (b) is a front view.

FIG. 2 is a diagram showing a displacement level of a resin raw material in a downstream portion of a screw in a hopper.

FIG. 3 is a diagram showing a displacement level of a resin raw material in a central portion of a screw in a hopper.

FIG. 4 is a diagram showing a method of detecting the presence or absence of a resin raw material by a displacement signal of an ultrasonic displacement sensor.

FIG. 5 is a diagram showing a method of detecting the presence / absence of a resin raw material by a displacement signal of an ultrasonic displacement sensor.

[Explanation of symbols]

1 Conical feeder (2-axis meshing taper screw feeder) 2 Screw 2a Screw flight 3 Cylinder 4 Hopper 5 Speed reducer 6 Motor 7 Stand 8 Strut 10 Ultrasonic sensor 11 Amplifier 12 Recorder 13 Timer 14 Comparator 15 Level setter 16 Signal processing vessel

Claims (8)

[Claims] 1. A method for detecting the presence or absence of input raw material in a biaxial meshing taper screw feeder used for supplying a rubber-based resin raw material to a kneading extruder, wherein an ultrasonic displacement sensor (10) is provided in the hopper (4). ) Is attached to the upper part of), the displacement level of the downstream part of the screw (2) in the hopper (4) is detected, and the presence or absence of the input raw material is detected using the displacement signal. 2. A displacement signal detected by an ultrasonic displacement sensor (10) is amplified by an amplifier (11) and input to one side of a comparator (14), and a comparator (14) outputs a level setter (15) from the level setter (15). The presence / absence of the input raw material according to claim 1, wherein the timer start signal is input to the timer (13) when it becomes lower than the level signal and the time-up signal is output when it does not rise above the level signal. how to. 3. A displacement signal detected by an ultrasonic displacement sensor (10) is amplified by an amplifier (11) and input to one side of a comparator (14) via a signal processor (16) to obtain a comparator (14). 2.) A method for detecting the presence or absence of a charged raw material according to claim 1, further comprising: 4. A device for detecting the presence or absence of input raw material in a biaxial meshing taper screw feeder used for supplying a rubber-based resin raw material to a kneading extruder, wherein the screw (2) in the hopper (4) is An apparatus for detecting the presence or absence of input raw material, characterized in that an ultrasonic displacement sensor (10) for detecting a displacement level of a downstream portion is attached to an upper part of a hopper (4). 5. An amplifier (11) for amplifying a displacement signal detected by an ultrasonic displacement sensor (10), a recorder (12) for recording the amplified signal, and a level setter (1).
5), a comparator (14) that compares the amplified signal with the signal from the level setter (15), a timer (13) that starts timing with the signal from the comparator (14) and outputs the signal, The device for detecting the presence or absence of the input raw material according to claim 4. 6. An amplifier (11) for amplifying a displacement signal detected by an ultrasonic displacement sensor (10), a recorder (12) for recording the amplified signal, and a signal processing for processing the amplified signal. Device (16) and level setting device (15)
And a comparator (14) for comparing the signals from the signal processor (15) and the level setter (15) and outputting the signals
An apparatus for detecting the presence or absence of the input raw material according to claim 4. 7. An apparatus for detecting the presence or absence of input raw materials according to claim 6, wherein the signal processor (16) is an average calculator. 8. An apparatus for detecting the presence or absence of input material according to claim 6, wherein the signal processor (16) is a low frequency filter.