JP2003285330A - Metering and supplying method for resin material and metering and supplying apparatus therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a supply method for a resin material for supplying the resin to a molding machine, a supply apparatus therefor and a metering hopper of which the metering accuracy is made hard to damage, even if the storage level of the resin material in the hopper is lowered. <P>SOLUTION: A metering and supplying method for the resin material is constituted so that the resin material is preliminarily charged in a hopper tank 3 in an amount consumed before the resin material is replaced and consumed without adding the resin material, until the resin material is replaced to reduce the residual amount in the tank. A metering and supplying apparatus 1 is equipped with the hopper tank 3 for drying the resin material P supplied to the molding machine to keep the same, the housing tank 4 connected to the discharge port of the hopper tank 3 to house the residual resin in the tank, and a rotary metering valve 5 of which the resin suction port is connected to the bottom part of the housing tank and the discharge port is connected to a resin transport pipe. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin material measuring method and apparatus which does not hinder the metering and discharging accuracy even if the remaining amount in a hopper tank for drying and storing pelletized resin material is small. .

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 2, a suction port of a rotary metering valve 5 capable of metering and discharging is directly connected to the bottom of a hopper tank 3 for drying and storing pelletized resin material, and the discharge port thereof is made of resin. It is used in a configuration in which the resin material P is metered and supplied by being connected to the transportation pipe 42.

At this time, a pelletized resin material is put into the hopper tank at a level of almost 100%, and is dried and then metered to the molding machine. After the preset time set in advance,
It is a control to add up to 100% level, so it is always 1
It was a method of holding a resin material at a level of 00%.

[0004]

However, according to the above-mentioned method, a large amount of the remaining material of almost 100% level in the hopper tank is extracted at the time of the production setup change to change the color and material type of the resin molded product, and a new It took a lot of time and effort to replace it with.

This is because, as shown in the conventional diagram of FIG. 2, when the remaining material in the hopper tank 3 becomes small, the flow of dry air blown into the hopper tank 3 causes
The downward discharge flow of the residual material is obstructed by the upward flow of the dry air blown out from the hot air outlet 23 as shown in FIG.

As a result, the flow of material to the suction port of the rotary metering valve becomes poor and unevenness occurs. As a result, there is a problem that the discharge amount of the rotary metering valve is disturbed and the metering accuracy deteriorates. It was necessary to hold a large amount of material at all times.

In this way, the hopper tank always stores the maximum amount of material. On the other hand, in the production operation, it is necessary to efficiently carry out various kinds of small amounts, which requires improvement of the efficiency of material replacement in the tank.

An object of the present invention is to improve the problem that a large amount of residual material in the hopper tank has to be extracted each time such a repeated setup change is performed, and the residual amount in the tank is reduced. Even if it does not hinder measurement accuracy even if it aims at providing the measuring method of the resin material and the measuring apparatus of the resin material.

[0009]

According to a first aspect of the present invention, there is provided a resin material measuring and feeding method, wherein hot air is blown into a hopper tank to dry and store the resin material, and the small amount is dispensed. It is characterized in that the required amount is charged into the hopper tank in advance, and the amount of consumption is reduced without adding the resin material until the material is changed to reduce the remaining amount in the tank when the material is changed.

According to this, most of the resin material charged in the hopper tank is consumed at the time of setup change, and when the resin material in the hopper tank is replaced, the remaining amount of extraction can be minimized and the amount of resin dried can be minimized. I can.

According to a second aspect of the present invention, there is provided a resin material measuring and feeding device, wherein a hopper tank for drying and storing the resin to be supplied to the molding machine and a storage tank connected to the hopper tank discharge port for storing the residual resin in the tank. And a rotary metering valve in which the resin suction port is connected to the bottom of the storage tank and the discharge port is connected to the resin transport pipe.

[0012] According to this, even if the flow rate of the dry air is obstructed at the bottom of the hopper tank due to the small amount of the resin material remaining, and even if it takes a long time for the flow of the dry air, the resin material is intermittently rotated downward during the measurement stoppage. Since it flows down to the storage tank and the storage tank is filled with the storage tank, it is possible to prevent variations in the suction efficiency of the rotary metering valve from decreasing. Therefore, even if the remaining amount is small, the weighing accuracy is not impaired.

According to a third aspect of the present invention, in the resin material measuring and feeding device according to the second aspect, the storage tank has an air exhaust wall after drying on a wall surface thereof. According to this, the dry air flow at the bottom of the hopper tank is guided to the storage tank below, so that the drying condition of the residual material can be maintained until the end.

According to a fourth aspect of the present invention, there is provided a resin material measuring and feeding device according to the second or third aspect, wherein the storage tank is provided with a detecting means for detecting the presence or absence of the resin material therein. According to this, all the remaining material of the hopper tank is stored in the storage tank below, so that the lower limit level of the hopper tank can be more reliably grasped. In addition, the material bridge in the hopper tank can be eliminated.

According to a fifth aspect of the present invention, there is provided the resin material measuring and feeding device according to the second to fourth aspects, wherein the storage tank is provided with an outlet for discharging the resin material inside thereof. According to this, since it can be extracted from the space at the end, the amount of residual material in the tank can be easily and reliably discharged from one location.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a conceptual diagram showing a resin material measuring and supplying device, and FIG. 2 is a hopper tank regarding an embodiment of the resin material measuring and supplying method and the resin material measuring and supplying device of the present invention. Fig. 3 is an explanatory view of the conventional system showing the storage weight in the height direction of the charging level in Fig. 3, and Fig. 3 shows the situation in which the residual amount of the resin material in the hopper tank is reduced and it is wound up by hot air for drying. FIG. 4 is a flow chart showing the operation contents of the resin material metering and feeding device,
It will be described with reference to FIG.

The function of the resin material metering and supplying apparatus 1 of the present invention will be described first. The resin material P in pellet form is plasticized by an extruder, cast into a molding die, and shaped by the molding die to produce a resin molded product. The pelletized resin material P used in this molding machine is introduced into the receiving port from the container, pneumatically conveyed, and introduced through the material suction pipe 29 of the resin material measuring and feeding device 1 according to the present invention.

The pelletized resin material P is stored in the hopper tank 3 of the resin material metering and feeding apparatus 1 and is exposed to hot air to reduce the water content in the resin material P and is stored in a dry state. This prevents the occurrence of defective resin molding.

The resin material P thus dried in the hopper tank 3 flows down below the tank while maintaining the dry state and flows from the suction port of the rotary metering valve 5 into the space between the blades of the rotary blades inside the valve body. This space transport volume 42 is extended and sent to the molding machine by being filled in this space volume, measured, half-turned, and discharged to the material transport tube 42 connected to the discharge port opened at the lower position. The material is introduced into the material suction unit 19 provided in the hopper tank 51.

Next, the resin material measuring and feeding device 1 of the present invention
The configuration will be described with reference to FIG. First, a hopper tank 3 for storing and drying the resin material P, a storage tank 4 of the present invention mounted on the bottom of the hopper tank,
It is composed of a rotary metering valve 5 for connecting the suction port to this tank and metering and discharging the resin material P.

Subsequently, each of the components is individually shown in FIG.
Will be explained. First, the hopper tank 3 includes a material charging unit 18 at the top of the tank, a hot air blower pipe 21 installed inside the tank by being connected to a hot air generator 22 installed outside the tank,
It is composed of a material discharge port 7 provided at the bottom of the tank.

First, the material feeding section 18 is composed of a cyclone 24A cylinder made of a can body having a conical shape downward, and can be sucked by a suction blower 28 via an intake pipe 32A at the upper portion of the cylinder and a bag filter 27. A supply valve 25A is provided at the bottom of the cylinder and is connected to the hopper tank 3, and a material suction pipe 29 is connected to the cyclone 24A cylinder from the tangential direction of the outer circumference.

Therefore, when the closing valve 25A is closed and the suction blower 28 is operated, the inside of the cyclone 24A cylinder is depressurized, and the intake air and the resin material P are sucked up into the cyclone 24A cylinder through the material suction pipe 29. Then, the resin material P is centrifuged and stored in the cylinder of the cyclone 24A. When the upper limit is reached, the suction blower 28 is stopped, the injection valve 25A is opened, and the resin material P can be injected into the hopper tank 3.

Subsequently, the hot air blowing pipe 2 installed inside the hopper tank 3 is connected to the hot air generator 22 installed inside the tank.
No. 1 has a gap between the inner surface of the hopper tank 3 whose wall surface is inclined so that the material does not stagnate toward the material discharge port 7 and in which a layer of resin flows down, as indicated by the arrow in the figure. Hot air can be blown to the resin material to heat it evenly. The hot air once flows into the upper part of the tank, enters the storage tank 4 through the material discharge port 7 at the bottom of the lower tank, and is exhausted from the exhaust wall 11.

Next, the storage tank 4 of the present invention mounted on the bottom of the hopper tank 3 will be described in detail with reference to FIG. The capacity of the storage tank 4 is formed in a size based on a single feed amount to the molding machine, and connecting flanges are provided on the upper and lower surfaces, respectively, and the internal volume is expanded by expanding the body portion between the flanges. It is manufactured in a shape that can be secured, and the upper and lower surfaces of the expansion wall portion are configured with inclined surfaces so as not to cause material stagnation.

Next, the storage tank 4 is provided with an air exhaust wall 11 according to the present invention, a material detecting means 13, and a resin material extracting port 15. As shown in FIG. 1, first, the air exhaust wall 11 is formed by partially cutting out the outer surface of the body portion between the flanges of the storage tank 4 and using a punching plate with a small hole through which a pellet-shaped resin material does not pass as a lid. The air vent is configured so as to cover and is configured to vent the exhaust hot air after being exposed by being pushed into the hopper tank 3.

Subsequently, as the material presence / absence detecting means 13, a powder level meter is used which can be detected by inserting a rotary blade into the tank 4 and eliminating the resin material blocking the rotation of the blade.

Further, the extraction port 15 for the resin material has a female screw short pipe attached to the lower inclined portion of the storage tank 4 as a plug screw connection port, and the extraction hose is provided with a funnel at the front end of the hose by removing the plug. The material extracted by the jig can be stored in the collection container, and the material can be easily replaced.

Next, the rotary metering valve 5 which connects the suction port to the lower surface of the above-mentioned storage tank 4 and measures and discharges the resin material P will be described with reference to FIG. The rotary metering valve 5 has its resin suction port connected to the bottom of the storage tank 4 to take in the resin material P and perform the function of a shutoff valve when the rotation is stopped, and is configured between the inner surface of the valve and the rotary vane when rotating. The material can be sequentially taken into the metering cavity through the suction port, half-turned, and the material taken in through the discharge port can be continuously discharged to measure the rotation.

The discharged resin material P is transported to a hopper tank 51 installed on the molding machine 50, as shown in FIG. Cyclone 24 connected on this tank
Connect the material transport pipe 42 to the body of B
Air intake valve 34 provided in the vicinity of the outlet of rotary metering valve 5 by reducing the pressure through intake pipe 32B connected to the top of 4B.
The resin material P discharged by the air introduced from the above is taken into the cyclone 24B cylinder, and the injection valve 25 at the bottom thereof is introduced.
B is opened and transported to the hopper tank 51.

The operation of the resin material measuring and feeding device of the present invention will be described below. Input amount calculation (S10)
Calculate the amount of molding material used until this material is replaced,
It is almost used up to minimize the remaining amount of the tank, and the amount charged into the tank is calculated by multiplying the number of moldings and the molding weight per one, and adding a margin.

In the material charging section (S11), the amount of the resin material obtained previously is measured, the material charging section 18 provided on the hopper tank 3 is operated, and the charging valve 25 is closed to suck the material. The blower 28 is operated to decompress the cyclone 24, and the resin material is taken into the cyclone 24 via the suction pipe 29 to release the decompression.

In the hopper tank for charging and storing (S12), the resin material taken into the cyclone 24 is charged into the hopper tank 3 by opening the charging valve 25, and this is repeated to charge the entire amount.

In the hot air drying (S13) in the hopper tank, the resin material P charged in the hopper tank 3 is blown into the material charged from the opening facing the lower surface of the hot air blowing pipe 21 to be dried.

Whether or not the hopper tank level for the molding machine is detected? In (S14), when the level of the molding machine hopper tank 51 falls below the upper limit as the molding machine operates, a new supply signal is issued to the resin material metering and supplying device after the installation time to replenish the dry and stored resin material. To do.

The metering valve rotation (S15) is a command from the above, and a predetermined rotation is given to the metering valve to supply the material discharge pipe 4
In the pneumatic transportation (S16) to be discharged to No. 2, the discharged resin material is sucked under reduced pressure into the cyclone 24 that is put into the hopper tank 51 for the molding machine provided on the resin molding machine and transported.

With / without storage tank level? (S17)
Monitors that the above-mentioned material metering and supplying operation can proceed to the next step as necessary when the storage tank level is present, and conversely, when the storage tank level is exhausted, an alarm is issued and the process cannot proceed to the next step.

Measurement timer incomplete / completed? (S18) is
When the metering valve rotates and the metering timer is completed, the metering stops, and conversely, when the metering time is not completed, the metering valve rotates and pneumatically conveys until the storage tank level runs out and an alarm is issued.

As described above, the metering valve rotation stop (S19) means that when the resin material dried in the hopper tank 51 for the molding machine is exhausted to a predetermined level, the metering valve rotation operation and pneumatic transportation are performed from the resin material metering and supplying device. It is automatically supplied according to a predetermined program, and this is repeated, and when the material is changed, the hopper tank 3 is used up so that the remaining amount is minimized.

[0040]

EXAMPLES Next, the residual amount of the resin material P in the hopper tank 3 was changed using the method of the present invention and the method of the prior art, and the weighing accuracy discharged from this tank was compared and confirmed below.

First, according to the present invention, as shown in FIG.
The storage tank of the present invention (having a volume of 9 l) is provided between the hopper tank 3 and the rotary metering valve 5, and the equipment conditions are as follows: hopper tank capacity: 500 kg, hot air temperature: 80-130.
° C, hot air volume: 20 m ³ / min, set value for measurement: 470
0 g, metering speed: 4000-5000 g / min. [Example 1] Next, the rotational weighing accuracy at that time was obtained by changing the amount according to the remaining amount in the tank shown in FIG. In Table 1, the excess / deficiency amount with respect to the weighing set value of 4700 g at each remaining amount (kg) position is shown as plus or minus gram value, and at the same time, the parenthesis value is also shown as the weighing accuracy in percentage to the weighing set value of 4700 g.

As shown in this result, the remaining amount in the tank is 47
Even if it was less than or equal to kg, it was -1.4% of the target value, and even if the remaining amount in the tank was as small as 10 kg, the weighing accuracy within this range was obtained.

[Comparative Example] The conventional method shown in FIG. 2 in which the storage tank of the present invention (having a volume of 9 l) is removed from FIG.
Similarly to the above, the remaining amount in the tank was changed and comparative measurement was performed to similarly determine the excess / deficiency amount (g) and the rotational measurement accuracy (%) under the above measurement conditions.

In this result, the remaining amount in the tank is 16
When it becomes less than 0 kg, the weighing accuracy rapidly deteriorates from 2.5%, and when the remaining amount in the tank becomes 10 kg, which is the minimum, -12.
It was 7%.

[0045]

[Table 1] From the results of Table 1, in the comparative example of the conventional method, when the remaining amount in the tank is 160 kg or less, the weighing accuracy rapidly deteriorates from 2.5%, and the remaining amount in the tank reaches the minimum of 10 kg, −
In contrast to the 12.7% variation, in the method of the present invention using the storage tank 4, the remaining amount in the tank is 47 kg.
Even below, the measurement accuracy was within this range even if the remaining amount in the tank was 10 kg, which was -1.4% of the target value. Thus, the effect of the present invention was confirmed.

The resin material metering and feeding method and the metering and feeding apparatus of the present invention are not limited to those shown in FIGS. 1 to 4, but may be in the following forms, for example. 1) The material feeding section 18 shows an air transportation method in this example, but other methods such as tube conveyor transportation can be used.

[0047]

According to the resin material measuring and feeding method of the first aspect and the resin material measuring and feeding apparatus of the second aspect, the sampling time at the time of setup change can be minimized, and the excess resin material is dried. Since no treatment is required, the switching time can be greatly shortened for repeated setup changes, and the drying energy can be saved. Since such a process does not impair the measuring accuracy by using the mechanism for inserting the storage tank of the present invention between the rotary measuring valve connected to the bottom of the hopper tank, the resin material in the hopper tank is minimized. Can be used up.

In the resin material metering and feeding device according to the third aspect, the efficiency of sucking the resin material into the rotary metering valve is further improved, so that the metering accuracy is further improved and the dry quality of the resin material can be maintained until the end.

In the resin material metering and feeding device according to the fourth aspect, since the lower limit level of the hopper tank can be more reliably grasped as the minimum amount, the remaining amount of the hopper tank can be controlled at the minimum level, and therefore the extraction remaining amount is It is possible to reduce the number accordingly and shorten the stage change.

In the resin material measuring and feeding device according to the fifth aspect, the time required for withdrawal can be shortened, and therefore the time required for setup change can be shortened.

As described above, the functions can be exhibited in the inventions relating to the resin material measuring and supplying method and the resin material measuring and supplying device according to claims 1 to 5 of the present application.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing a resin material metering and supplying device.

FIG. 2 is an explanatory view of a conventional apparatus showing a storage weight in a height direction in a hopper tank.

FIG. 3 is a diagram showing a situation in which a residual amount of a resin material in a hopper tank is reduced and the resin material is wound up by hot air for drying.

FIG. 4 is a flowchart showing the operation of the resin material metering and supplying device.

[Explanation of symbols]

P resin material 1 Resin material metering device 3 hopper tank 4 storage tank 5 rotary metering valve 11 exhaust wall 13 Material presence detection means 15 Material outlet 23 Hot air outlet 50 resin molding machine 51 Hopper tank for molding machine

Claims (5)

[Claims] 1. In a method of metering and feeding resin material in which hot air is blown into a hopper tank to dry-store the resin material and to dispense and meter the resin material, a required amount until the material is switched is put into the hopper tank in advance, and the resin material is switched until the material is switched. A method of metering and feeding a resin material, characterized in that the amount of consumption is reduced without adding the element and the remaining amount in the tank is reduced when the material is changed. 2. A hopper tank for drying and storing the resin to be supplied to the molding machine, a storage tank connected to the hopper tank discharge port for storing the residual resin in the tank, and the resin at the bottom of the storage tank. A resin material metering / supplying device comprising at least a rotary metering valve having a suction port connected thereto and the discharge port connected to a resin transport pipe. 3. The resin material metering / supplying device according to claim 2, wherein the storage tank has an air exhaust wall after drying on a wall surface thereof. 4. The storage tank is provided with a detection means for detecting the presence / absence of a resin material inside the storage tank.
The metering and feeding device for the resin material according to. 5. The resin material metering / supplying device according to claim 2, wherein the storage tank is provided with an outlet for discharging the resin material inside thereof to the outside.