JPH06104189B2 - Mixer for raw materials - Google Patents

Description

TECHNICAL FIELD The present invention relates to a mixing device for controlling a mixing amount by gravimetric measurement, and more particularly to a mixing device for powder and granular material.

BACKGROUND ART For example, in the production of plastic films and resin molded products, a plurality of resin pellets are mixed and supplied in predetermined amounts, and melting, molding, rolling, etc. are performed. Therefore, it is necessary to accurately measure the amount of resin pellets supplied in order to form a product so that the quality of the film or the molded product is uniform.

Conventionally, in the supply of such resin pellets, for example, by measuring and mixing with a vessel such as a normal mass, or by mixing the resin pellets measured in time units from the outlet so that the resin pellets come out a certain amount, This was supplied to the molding section. According to this method, since the specific gravity and the formation of resin pellets differ depending on the raw materials, accurate compounding cannot be performed, and it is difficult to form a product of uniform quality, and there is a demand for a device that can more accurately measure and compound.

The present invention eliminates the drawbacks of the prior art and continuously supplies the powdered or granular material to be mixed, accurately measures the weight of the powdered or granular material, and mixes from the measurement of the powdered or granular material. The purpose is to continuously perform up to.

DISCLOSURE OF THE INVENTION According to the present invention, a powdery or granular material mixing device for mixing a plurality of types of powdery or granular material is formed in a cylindrical shape with a lower part converging downward, and a discharge port at the tip of the lower part. Weighing hopper formed with, the raw material supply means that supplies multiple types of powdered and granular raw materials without contacting the weighing hopper, the discharge port closing member that opens and closes the discharge port, and the weighing hopper is lifted and held upward. And a weight sensor that supports the weighing hopper via the hanging metal fitting on a vertical line that passes through the approximate center of gravity of the weighing hopper, and a mixing unit that mixes the raw material powder and granules weighed by the weighing hopper. A plurality of types of powdery or granular material raw materials supplied to the weighing hopper are weighed and compared with set values, and then discharged to the mixing means.

Description of Embodiments Next, with reference to the accompanying drawings, embodiments of the mixing apparatus for powdery or granular material according to the present invention will be described in detail.

FIG. 1 (a) shows a raw material supply part and a weight measuring part of a mixing device for mixing two kinds of powdery or granular material.

Raw materials such as resin pellets are stored in the hoppers 10 and 12, and the weighing hoppers alternate from the hoppers 10 and 12.
Raw materials are supplied to 18. First, the raw material contained in the hopper 10 is sent to the weighing hopper 10 by the raw material transport pipe 14.
The raw material transfer pipe 14 is inserted into a hole 18a formed in the weighing hopper 18 in a non-contact manner up to a substantially central portion of the weighing hopper 18 and arranged horizontally.

The raw material conveying pipe 14 and the hopper 10 are connected by a connecting box 20, and inside thereof, a conveying spiral screw 22 is provided as shown in FIG. Is sent to almost the center of the weighing hopper 18 and falls. In this case, the discharge port 32 opened at the bottom of the weighing hopper 18 is closed by the discharge shutter 30. The operation of supplying and stopping the raw materials from the hoppers 10 and 12 is based on the sequence control described later.

Two suspending members 18b are provided on the upper surface of the lid portion 18c of the weighing hopper 18 at symmetrical positions with respect to the center, and the hooks 24 of the suspending fittings 24 are inserted into the suspending holes 18b. This hanging bracket
When the weighing hopper 18 is suspended by 24, the support plate 24b supporting the hook 24a supports the fulcrum 24c which becomes horizontal,
A weight sensor 28 fixed to the device via a cushioning rubber 26
Is installed.

As shown in FIG. 1 (c), the discharge shutter 30 has a tapered closed portion 30a and a conical portion 30b whose lower portion is formed to fit the shape of the discharge port 32. The conical portion 30b has the effect that the raw material is quickly deposited on the lower part of the weighing hopper 18, the center of gravity of the weighing hopper 18 is moved as low as possible, and the resistance of the raw material can be raised at the time of discharge to be small. A lift rod 30c is connected to the discharge shutter 30 in order to open and close the discharge port 32, and the lift rod 30c penetrates a hole 18d formed at the center of the lid portion 18c of the weighing hopper 18 in a non-contact manner. A disk 30d is provided on the top. For this reason, the weighing hopper 1
When the raw material is measured by 8, the discharge shutter 30 is the weighing hopper 1.
It is supported on the bottom of 8.

When the weight sensor 28 senses that the set weight of raw material has been supplied to the weighing hopper 18, the discharge opening / closing mechanism 34 fixed to the mixing device operates. That is, the cylinder
34a is driven, and the elevating plate 34c ascends via the cylinder 34a and the piston 34b. Notch at the tip of the lift plate 34c
34d is formed and sandwiches the lifting rod 30c in a non-contact manner. The area of the notch 34d is smaller than that of the disk 30d, and the ascending distance of the notch 34d is larger than the distance from the lower surface of the disk 30d to the upper surface of the lift plate 34c at the notch 34d portion. Therefore, when the ejection opening / closing mechanism 34 operates to “ejection open”, the disc 3 is lifted by the lifting of the elevating plate 34c.
0d is raised, whereby the discharge shutter 30 is raised as shown by the dotted line in FIG. 1 (c), and the raw material is dropped from the discharge port 32 as shown by the dotted line.

When the weight sensor 28 detects that the raw material discharge is completed,
The operation enters "discharging close", and the lifting plate 34c descends and the disk 3
0d leaves the contact with the lifting plate 34c. Therefore, the elevating rod 30c falls freely, and the discharge port 32 is closed by the closing portion 30a as shown by the solid line in FIG. 1 (c).

Next, another powdery or granular material is supplied from the hopper 12 to the weighing hopper 18, is weighed in the same process as above, and falls from the discharge port 32.

FIGS. 2A and 2B show the overall configuration of an embodiment of a mixing apparatus that mixes three types of raw materials. FIG. 2 (a) is a front view of the mixing apparatus, and FIG. 2 (b) is a side view thereof.

The raw materials contained in the hoppers 36, 38 and 40 are fed by the transport motor 4
The raw materials accommodated in the hopper 36 are supplied to the weighing hopper 50, and the raw materials accommodated in the hoppers 38 and 40 are supplied to the weighing hopper 52 via the raw material conveying pipes by driving 2, 44 and 46.
The raw material supplied to each weighing hopper is weighed by the weight sensor 28 (Fig. 1 (a)) in the load cell section 48, and after weighing, falls into the mixing tank 58 from the discharge ports 54 and 56 of the weighing hoppers 50 and 52. To do. At this time, the weighing hoppers 50 and 52 and the mixing tank 58 are not in contact with each other.

The raw materials in the mixing tank 58 are agitated by the mixing motor 60, and after mixing, the raw material discharge cylinder 62 is driven and dropped into the mixed raw material receiving hopper 64 from a discharge shutter (not shown). The amount of the mixed raw material in the mixed raw material receiving hopper 64 is monitored by the level sensor 66.

The control panel 68 is provided with a metering setting switch 72 for setting the amount of each raw material, an indicator 70 for showing the actual mixing ratio and amount, a built-in A / D converter, a micro computer (both shown). No)).

The operation flow of the apparatus described above is shown in FIGS.
Shown in.

In the flow of FIG. 3 (a), when two kinds of raw materials are mixed, the raw material A is first weighed and discharged by the weighing hopper,
This is an example of later measuring and discharging the B raw material. In the flow of FIG. 3 (b), after discharging the A raw material after the measurement, the B raw material is added to measure the total of the A and B raw materials, and then the B raw material is measured. A,
This is an example of simultaneously discharging the B raw material.

Next, FIG. 4 shows an example of a block diagram of a programmable controller regarding an operation sequence for mixing two kinds of raw materials. An input interface 78 and an output interface 82 are attached to the CPU unit 80. The signals from the weight sensors 28a and 28b are amplified by the amplifiers 74a and 74b, respectively, and the A / D converters 76a and 76b are amplified.
Is converted from an analog signal to a digital signal and input to the CPU unit 80 through the input interface 78. On the other hand, the signals from the weighing setting switches 72a and 72b are previously input and stored in the CPU unit 80 through the input interface 78. The CPU unit 80 is
The drive signals are output to the carry motors 16a and 16b through the output interface 82 until the converted digital amount sent from the weight sensors 28a and 28b matches the stored set amount.

When the converted digital amount from the weight sensors 28a and 28b and the digital amount set from the weighing setting switches 72a and 72b match, the CPU unit 80 outputs a stop signal to the carry motors 16a and 16b via the output interface 82. After a predetermined short time has passed, a "discharge open" signal is output to the discharge opening / closing mechanism section 34, and then the mixing motor
The drive signal is output to 60.

The discharge of the raw material ends when it is detected from the signal from the weight sensor 28a or 28b that the weight of the weighing hopper is equal to the tare. When the discharge of the raw material is completed, the CPU unit 80 sends a “discharge close” signal to the discharge opening / closing mechanism unit 34 via the output interface 82. The mixing motor 60 is CP
Stops after the time set for U unit 80 has elapsed. The sequence below returns to the first operation.

The CPU unit 80 not only sets and commands the above-mentioned operation sequence, but also calculates the weight effect of the discharge shutter given to the tare of the weighing hopper, that is, the effect of adding when measuring raw materials and becoming zero when discharging raw materials. Calculate the exact actual weight of. Further, the rotation speed of the carry motor is controlled so that the speed at which the raw material is sent to the weighing hopper is changed between the start and the end. Further, the timing of supplying the raw material to the weighing hopper and discharging the raw material from the weighing hopper can be optimized in consideration of the inertia of each part of the apparatus.

As described above, according to the present embodiment, it is possible to continuously supply, measure, and mix a plurality of raw materials, and it is not necessary to temporarily transfer the raw materials to be weighed to a container as in the conventional case. For this reason, the weighing hopper is provided with a weight sensor at the fulcrum, and the feeding and discharging of the raw material are always performed on the vertical line of the center of gravity of the weighing hopper, so that the weight sensor can always detect the weight of the raw material to be measured.
Further, since a signal is continuously obtained from the weight sensor, by processing this signal by the CPU unit, not only the actual weight of the raw materials can be calculated but also the timing of weighing and mixing can be controlled to the optimum speed.

In more detail, the features of the present invention are summarized as follows: (1) The raw material conveying pipe does not come into contact with the weighing hopper, which does not hinder weighing.

(2) The raw material is dropped on the vertical line of the center of gravity of the weighing hopper to suppress lateral shake of the weighing hopper.

(3) Since the raw material is supplied through the hole on the side of the weighing hopper, it is difficult for dust and dirt to enter.

(4) Since the weighing hopper is of a hanging type and is supported above the vertical line of the center of gravity and the weight sensor is provided, the weight is accurately measured without considering the biased effect of the way the raw material enters the weighing hopper. You can measure.

(5) The discharge shutter of the weighing hopper is made to fall on the vertical line of the center of gravity to minimize the impact on the weight sensor.

(6) The lower part of the discharge shutter of the weighing hopper has a conical shape, so that the raw materials dropped in the weighing hopper are easily accumulated below, and the sealing force of the discharge port is increased, and the resistance of the raw materials is discharged to easily pull up. I made it possible to do it.

(7) The discharge shutter of the weighing hopper is in contact with only the weighing hopper and the discharge port when measuring the raw material, and stable weight measurement can be performed.

(8) A microcomputer that processes continuous signals from the weight sensor enables accurate weighing, calculation of integrated amount, and optimum setting / control of raw material supply / measurement / mixing speed.

Effect According to the powder fluid raw material mixing apparatus of the present invention, the powder fluid raw material can be continuously and accurately measured by one weight sensor, the powder fluid raw material can be mixed, and the time required for the process can be optimized. Yes, no separate steps for weighing and mixing are required.

[Brief description of drawings]

FIG. 1 (a) is a perspective view showing an embodiment of a mixing apparatus for raw material of granular material according to the present invention, FIG. 1 (b) is a sectional view of the raw material conveying mechanism of FIG. 1 (a), FIG. FIG. 2C is a diagram for explaining the functions of the discharge port and the discharge shutter of the weighing hopper of FIG. 1A, FIG. 2A is a front view showing another embodiment of the present invention, and FIG. ) Is a side view of the apparatus of FIG. 2 (a), FIG. 3 (a) is a flow chart showing the operation of the apparatus of FIG. 1 (a), and FIG. 3 (b) is of FIG. 1 (a). FIG. 4 is a flow chart showing another operation of the apparatus, and FIG. 4 is a block diagram showing a control unit for controlling the operation of the mixing apparatus according to the present invention. Explanation of the symbols of the main parts 10,12 …… Hopper 14 …… Raw material transport pipe 16… Transport motor 18 …… Weighing hopper 28 …… Weight sensor 30 …… Discharge shutter 32 …… Discharge port 34 …… Discharge opening / closing mechanism Part 34a …… Cylinder 34c …… Elevating plate 58 …… Mixing tank 60 …… Mixing motor 64 …… Mixed material receiving hopper 68 …… Control panel 72 …… Measurement setting switch 80 …… CPU unit

Claims (5)

[Claims] 1. A mixing device for powdery or granular material for mixing a plurality of types of powdery or granular material, wherein the device is cylindrical and has a conical shape with a lower part converging downward and is discharged to the tip of the lower part. A weighing hopper having an outlet, a raw material supply means for supplying the plurality of types of powdered and granular raw materials to the weighing hopper in a non-contact manner, an outlet closing member for opening and closing the outlet, and the weighing hopper And a weight sensor that supports the weighing hopper via the hanging metal fitting on a vertical line that passes through a substantial center of gravity of the weighing hopper, and the granular material weighed by the weighing hopper. Mixing means for mixing the raw materials, a plurality of types of powder or granular material raw material to be supplied to the weighing hopper is measured and compared with a set value, and then discharged to the mixing means Body material mixing device. 2. The discharge port closing member has a conical shape in an upward direction and a downward direction, and an elevating rod is attached to an upper end portion,
The mixing apparatus for powdery or granular material according to claim 1, wherein the discharge port closing member can be moved up and down in an upper portion of the weighing hopper. 3. The mixture of powdery or granular material according to claim 1, wherein the powdery or raw material supplying means supplies the powdery or granular material through a conveying pipe inserted laterally into the weighing hopper. apparatus. 4. The powdery or granular material mixing device further has a discharge port opening / closing mechanism for vertically moving the discharge port closing member via the elevating rod, and after measuring the powdery or granular material,
The powder / granule raw material mixing apparatus according to any one of claims 1 to 3, wherein the powder / granule raw material is dropped by raising the discharge port closing member. 5. The powder / granule raw material mixing device further has a control means, which controls a signal continuously obtained from the weight sensor and supplies the weight of the powder / granular raw material. The apparatus for mixing powdery or granular material according to any one of claims 1 to 4, wherein measurement, supply amount to the weighing hopper, timing of supply and discharge, and speed are controlled.