JPH0540004Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> The invention is a method for continuously supplying uniformly sized powder and granules such as plastic pellets to a plastic molding machine or a processing machine in its preceding stage. This invention relates to a quantitative feeding device.

<Conventional technology> Conventionally, in order to reduce the pressure exerted by the powder or granule itself on the feeder to which the powder or granule is to be supplied in a fixed amount and maintain it at a nearly constant value, a stirring rotor is provided in a hopper connected to the top of the feeder. was used.

<Problem to be solved by the invention> Since powder and granular materials are surrounded by air, the smaller the particle size, the lower the apparent specific gravity, and the more the change in volume due to pressure increases. Therefore, in order to supply a fixed amount of powder or granules, it is important to control the pressure acting on the granules to be measured at a constant level.

Therefore, the purpose of this invention is to provide a fixed quantity supply of plastic pellets, etc., in which the force acting on the weighed powder is always constant and does not become excessive, regardless of the amount of powder or granule stored in the hopper. The purpose is to provide equipment.

<Means for Solving the Problems> The quantitative feeding device for plastic pellets, etc. of the present invention includes a first feeder that continuously discharges the material filled in a container in fixed amounts by a first rotor; A relay pipe with a substantially constant cross-sectional area extending upward from the material inlet of the feeder No. 1, and a relay pipe that is connected to the top of the relay pipe and controls the amount of material transferred by turning on/off or changing the rotation speed. 2
A second feeder that transfers the material by the rotation of the rotor, a hopper that supplies the material to the second feeder, a level sensor disposed at a predetermined position of the relay pipe, and a detection signal from the level sensor. The present invention is characterized in that it includes a control device that controls the rotation of the second rotor.

<Function> Since the first feeder continuously discharges the material in fixed amounts, the material in the relay pipe is also consumed at a constant rate.In contrast, the material level in the relay pipe is always maintained at the target value of the fixed amount. Since the pressure caused by the weight of the material acting on the first feeder is maintained at a constant value, the apparent specific gravity of the material filled in the first feeder also decreases. It is kept at a constant value.

<Example> FIG. 1 shows an internal sectional view of an embodiment of the present invention.

The first feeder 1 has a screw rotor 3 installed inside a horizontal cylinder container 2. By rotating this rotor 3 with a motor 4, the material filled in the container is transferred from a discharge port 5 to the next stage. equipment, such as an extruder for a plastic molding machine. As the motor 4, a motor with a speed reduction mechanism or a variable speed motor using an inverter is used. 1st
A material inlet 6 of the second feeder 1 is connected to a material relay pipe 7 extending upward, and the upper end of this relay pipe 7 is further connected to a material outlet of a second feeder 8. This second feeder 8 has a screw rotor 10 rotating inside a horizontal cylinder container 9 in the same way as the first feeder.
The amount of material transferred is controlled by rotationally driving. The motor 11 is a motor with a reduction mechanism, a pulse motor, or a variable speed motor using an inverter, and when the motor stops, the material transfer also stops, and when the motor rotates, the amount of material is transferred in proportion to the rotation angle. Ru. Hopper 1 that stores material above material input port 12 of second feeder 8
3 is provided, and a material introduction pipe 14 is provided above it. A powder level sensor 15 is disposed at a predetermined position of the relay pipe 7 described above. This level sensor 15 consists of two sensors, upper and lower, that detect the presence or absence of powder or granular material, and determines whether the powder or granular material is located above, below, or between the two sensors. do. The output signal of this sensor 15 is input to the control circuit section 16, and the drive of the motor 11 is controlled by the control output signal.

In this device, when the level of the material in the relay pipe 7 is lower than the level sensor 15, the motor 11 is rotationally driven to replenish the material, and when the level is between the two level sensors 15 or , when the level is higher than the level sensor 15, the motor 11 is stopped and the supply of material is stopped. Therefore, the material level is always maintained at the location of the level sensor 15.

FIG. 2 shows an internal sectional view of another embodiment of the present invention. The difference between this embodiment and the previous one is that the second feeder 20 is vertical, and the relay pipe 7 and the cylinder container 21 of the second feeder 20 are coaxially and continuously provided. , the hopper 2 is moved diagonally upward from the top of the cylinder container 21.
It's growing by 2. There is no substantial gap between the outer diameter of the screw rotor 23 rotating inside the cylinder container and the inner diameter of the lower part of the cylinder container, so that when the rotor 23 stops, free fall of the material does not occur. Components that are the same as those in the embodiment shown in FIG. 1 are given the same reference numerals, and their description will be omitted.

<Effect of the invention> According to the invention, the pressure caused by the material itself in the first feeder that supplies the material to be measured is maintained at a constant value regardless of the amount of powder or granular material in the hopper. The supply amount is accurately proportional to the rotation angle of the rotor shaft, and powder and granular material can be continuously supplied with high precision.

[Brief explanation of the drawing]

Fig. 1 is an internal sectional view showing an embodiment of the present invention;
The figure is an internal sectional view showing another embodiment of the present invention. 1...First feeder, 7...Relay pipe, 8...
second feeder, 11... second feeder motor, 13... hopper, 15... level sensor,
16...Control circuit section.

Claims (1)

[Scope of utility model registration request] a first feeder that continuously discharges the material filled in the container in fixed quantities by a first rotor; a relay pipe with a substantially constant cross-sectional area extending upward from the material inlet of the first feeder; A second feeder that transfers material by the rotation of a second rotor that is continuously installed at the top of the relay pipe and controls the amount of material transferred by turning on/off or changing the rotation speed; A method for quantifying plastic pellets, etc., comprising a hopper for supplying materials, a level sensor disposed at a predetermined position of the relay pipe, and a control device for controlling the rotation of the second rotor based on a detection signal from the level sensor. Feeding device.