JPH07119031B2 - Automatic material change method in injection molding equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an improvement in an automatic material changing method in an injection molding facility.

(Prior Art) Conventionally, when plastic moldings of different colors or the like are continuously injection-molded by an injection molding machine, for example, the actual method of Sho 61-67
As disclosed in Japanese Patent Laid-Open No. 107, a plurality of sub hoppers are connected to a main hopper that supplies an injection molding material to an injection cylinder of an injection molding machine, and a predetermined amount of each of the sub hoppers is stored in a predetermined amount. A method is known in which different injection molding materials are automatically switched and supplied to the main hopper by a valve switching operation.

(Problems to be Solved by the Invention) However, in the above method, the desired injection molding material can be promptly supplied to the main hopper only by the valve switching operation, so that the molding cycle time can be shortened. Although it is possible, a plurality of sub-hoppers must be prepared according to the number of injection molding materials having different colors, which causes a drawback that the injection molding equipment becomes large.

Therefore, by connecting only one sub hopper to the main hopper and switchingly supplying the injection molding materials of different colors and the like to the one sub hopper, the injection molding equipment can be made compact. There is also a method.

By the way, in this method, during the injection molding in which the injection molding material in the main hopper is being supplied to the injection cylinder of the injection molding machine, the supply of the injection molding material to the sub hopper is stopped for material change. When the sub hopper becomes empty, the main hopper waits in that state until the injection molding material inside is supplied to the injection cylinder of the injection molding machine and becomes empty, that is, until the current injection molding is completed, and then When both the sub hopper and the main hopper have become empty, the sub hopper is first cleaned, and then the main hopper is cleaned. After cleaning both hoppers, the injection molding material for the next injection molding is supplied to both hoppers to replace the material with the conventional injection molding material. Therefore, in this method, no other work is performed during the cleaning of the both hoppers, and the time required for this cleaning becomes a loss time, and the molding cycle time becomes longer than in the case of the above-mentioned publication. There is a drawback that.

The present invention has been made in view of the above points, and an object of the present invention is to provide a main hopper that supplies an injection molding material to an injection cylinder of an injection molding machine, and to connect only one sub hopper to the main hopper. By properly setting the cleaning timing of the hopper, the auxiliary hopper can be cleaned without waiting until the main hopper becomes empty, which means that the cleaning time can be cut in half, and The objective is to achieve both a reduction in cycle time and a compact injection molding facility.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the solution means of the present invention is a sub-hopper for storing a fixed amount of injection molding material, and a sub-hopper connected to the sub-hopper and stored in the sub-hopper. As an automatic material change method in an injection molding facility equipped with a main hopper that supplies the injection molding material to the injection cylinder of the injection molding machine, first, the injection molding material in the main hopper is supplied to the injection cylinder of the injection molding machine. During the injection molding, when the supply of the injection molding material to the sub hopper is stopped due to the material change and the sub hopper becomes empty, the inside of the sub hopper is cleaned to make an injection different from the injection molding material. Store the molding material in the sub hopper. Next, when the injection molding material inside the main hopper is supplied to the injection cylinder of the injection molding machine and becomes empty, the inside of the main hopper is cleaned to transfer the injection molding material inside the sub hopper to the main hopper. To supply.

(Operation) With the above configuration, in the method of the present invention, the supply of the injection molding material to the sub hopper is stopped for material change, the injection molding material in the sub hopper is supplied to the main hopper, and the sub hopper is emptied. Then, during the injection molding in which the injection molding material is supplied from the main hopper to the injection cylinder of the injection molding machine, the inside of the sub hopper is cleaned, and then an injection molding material different from the injection molding material is stored in the sub hopper. . Next, when the injection molding material inside the main hopper is supplied to the injection cylinder of the injection molding machine and becomes empty, the inside of the main hopper is cleaned, and then the injection molding material inside the sub hopper is transferred to the main hopper. It is supplied and the material change is completed.

Therefore, the auxiliary hopper is cleaned without waiting until the main hopper becomes empty, that is, during the injection molding, the cleaning time is halved, thus shortening the molding cycle time and the injection. The compactness of the molding equipment can be achieved at the same time.

(Example) Hereinafter, the Example of this invention is described based on drawing.

First, before describing an automatic material changing method according to an embodiment of the present invention, an injection molding equipment to which this automatic material changing method is applied will be described.

As shown schematically in FIG. 2, the injection molding equipment comprises an injection molding machine 3 in which a screw 2 is rotatably arranged in an injection cylinder 1, and the injection cylinder 1 rear part of the injection molding machine 3 is provided. A main hopper 4 for supplying, for example, a chip-shaped injection molding material to the injection cylinder 1 is attached to the side, and the injection molding material supplied from the main hopper 4 to the injection cylinder 1 and heated and melted is loaded into the screw 2. A molded product is injection-molded by injection-filling the mold 5 by a rotating operation. An air blow nozzle 7 for blowing off the injection molding material and its powder remaining on the inner wall is provided on the entire circumference of the corner between the upper opening end of the main hopper 4 and the upper lid 6. Further, the material supply cylinder portion 8 of the main hopper 4 is provided with a plate 10 that connects and disconnects the inside of the main hopper 4 and the inside of the injection cylinder 1 of the injection molding machine 3 by the expansion and contraction operation of the slide damper 9.

A sub hopper 11 for stocking a fixed amount of injection molding material is connected to the upper lid 6 of the main hopper 4, and the sub hopper 11 is
For example, it is connected through a supply pipe 12 to a plurality of material supply devices (not shown) that store different types of injection molding materials such as different colors,
The injection molding material of each material supply device is switched and supplied by the switching operation of the valve. Also,
A filter 13 is provided near the upper end of the sub hopper 11,
An air blow nozzle 14 for blowing off the injection molding material and its powder remaining on the inner wall is provided on the entire lower surface thereof. Further, the material supply cylinder portion 15 of the sub hopper 11 is provided with a plate 17 which connects and disconnects the inside of the sub hopper 11 and the inside of the main hopper 4 by the expansion and contraction operation of the slide damper 16. A suction pipe 18 is connected to the upper end of the sub hopper 11, and the sub hopper 11 is connected to a suction device (not shown) via the suction pipe 18. The injection molding material and its powder remaining adhered to are sucked into the sub hopper 11.

On the other hand, the main hopper 4 is connected to the suction device via a branch pipe 19 branched from the suction pipe 18, and the suction operation of the suction device causes the inside of the main hopper 4 blown off by the air blow nozzle 7. The residual injection molding material and its powder are sucked and discharged to the outside of the main hopper 4 through the branch pipe 19. A switching valve 20 is provided at a branch portion of the suction pipe 18 to switch suction between the main hopper 4 and the sub hopper 11.

Next, an automatic material changing method in the injection molding equipment configured as described above will be described with reference to the flowchart of FIG.

First, when START is started and injection molding is started, the injection molding material in the main hopper 4 is supplied from the material supply cylinder portion 8 to the injection cylinder 1 of the injection molding machine 3 in step S ₁ , and the injection molding material heated and melted When the screw 2 is rotated, the mold 5 is injection-filled and a molded product is injection-molded. In this state,
The auxiliary hopper 11 is supplied from one of a plurality of material supply devices via a supply pipe 12 so that a fixed amount of injection molding material is always stored, and the injection molding stocked in the auxiliary hopper 11 is supplied. The material is supplied so that the inside of the main hopper 4 is not empty.

Then, the process proceeds to a step S _2, in the main hopper during injection molding which is supplied to the injection cylinder 1 of an injection molding machine 3 injection molding material 4, the supply of injection molding material for the sub-hopper 11 of the material re Therefore, it is determined whether or not it has stopped, and if this determination is YES, the process proceeds to step S ₃ to determine whether or not the sub hopper 11 has become empty, while the above determination is made.
If NO, wait until the supply of injection molding material is stopped.

Then, when the determination in Step S ₃ of YES step S
_Proceeding to _4, after the suction operation of the suction device makes the inside of the sub hopper 11 a negative pressure and sucks the injection molding material and its powder remaining in the supply pipe 12 into the sub hopper 11, air is blown from the air blow nozzle 7. Then, the injection molding material and its powder remaining on the inner wall of the sub hopper 11 are blown off from the inner wall of the sub hopper 11, that is, cleaned, and the process proceeds to step S ₅ . On the other hand, when the determination is NO, the sub hopper 11 waits until it becomes empty.

After that, in step S ₅ , it is determined whether or not the air blow in step S ₄ has timed out after a predetermined time, that is, whether or not the cleaning is completed, and if this determination is YES, the process proceeds to step S ₆ . Is a slide damper on the side of the sub hopper 11.
After the opening operation (contraction operation) of 16 is carried out, the plate 17 is retracted so that the main hopper 4 and the sub hopper 11 are communicated with each other, and then the air inside the sub hopper 11 is blown again in step S ₇ to blow the inner wall of the sub hopper 11. The injection molding material and its powder blown off more are supplied into the main hopper 4. Thereafter, the sub-hopper-side sliding damper 16 by closing operation (stretching operation) in step S _8, after blocking the by allowed advancing plate 17 and the main hopper 4 and the sub-hopper 11, the in step S ₉ The next injection molding material having a different color from that of the injection molding material is supplied from another material supply device to the auxiliary hopper 11 through the supply pipe 12 and stored. On the other hand, if the determination is NO, the process waits until the time for the air blow in step S ₄ is up.

Thereafter, the process proceeds to step S _10, after switching on the main hopper 4 side via the branch pipe 19 by the suction pipe 18 switching operation of the switching valve 20, the main hopper 4 in step S ₁₁ is injection-molded inside it It is determined whether the material is supplied to the injection cylinder 1 of the injection molding machine 3 and is empty. Then, the sliding damper 9 of the main hopper 4 side is closing operation (stretching operation) proceeds to step S ₁₂ if the determination is YES, thereby the main hopper 4 brought forward plate 10 and the injection cylinder 1 After shutting off, in step S ₁₃ , air is blown from the air blow nozzle 14 to blow off the injection molding material and its powder adhering and remaining in the main hopper 4, that is, at the same time, the suction operation of the suction device causes the above The blown-off injection molding material and its powder are discharged to the outside through the branch pipe 19, and the process proceeds to step S ₁₄ . On the other hand, if the above determination is NO, the process waits until the inside of the main hopper 4 becomes empty.

Thereafter, in step S _14, air blow and suction in step S ₁₃ it is determined whether or not or that is cleaning time is up to lapse of a predetermined time period has been completed, step S ₁₅ in the case of this determination being YES Next, the sub hopper side slide damper 16 is opened (contracted), the plate 17 is retracted by this, the main hopper 4 and the sub hopper 11 are communicated, and the next injection molding stocked in the sub hopper 11 is carried out. Material is fed into the main hopper 4. On the other hand, if the determination is NO wait air blow and suction in Step S ₁₃ is timed up.

Then, it is determined whether the supply to the main hopper 4 side of the next injection molding material (first purge) is completed in step S _16, the main hopper side in step S ₁₇ in a case in which this determination is YES by the sliding damper 9 is open movement (contraction operation), after communicating the with retracted the plate 10 and the main hopper 4 and the injection cylinder 1, the next injection molding material in step S ₁₈ is supplied to the main hopper 4 Supply to the injection cylinder 1 side (second purge) is started, and the material change is completed. On the other hand, if the determination is NO, the process waits until the first purge is completed.

As described above, in this embodiment, during the injection molding in which the injection molding material is supplied from the main hopper 4 to the injection cylinder 1 of the injection molding machine 3, the supply of the injection molding material to the sub hopper 11 is stopped for the material change. When the injection molding material in the sub hopper 11 is supplied to the main hopper 4 and the sub hopper 11 is emptied, first, the sub hopper is stopped without stopping the injection molding.
After cleaning the inside of 11 with an air blow, the next injection molding material is supplied into the sub hopper 11 for storage. Then, when the injection molding material inside the main hopper 4 is supplied to the injection cylinder 1 of the injection molding machine 3 and becomes empty, the main hopper 4 is cleaned by air blow and suction, and then the sub hopper 11 is used. Material change is completed by supplying the next injection molding material stored in the main hopper 4.

From this, the auxiliary hopper 11 can be cleaned without waiting until the main hopper 4 becomes empty, that is, during the injection molding, whereby the cleaning time can be halved and the molding cycle time can be shortened. It is possible to achieve both compactness of the injection molding equipment.

(Effects of the Invention) As described above, according to the method of the present invention, the injection molding material in the main hopper connected to the sub hopper that stores a fixed amount of injection molding material is supplied to the injection cylinder of the injection molding machine. During the injection molding, when the supply of the injection molding material to the sub hopper is stopped due to the material change and the sub hopper becomes empty, the inside of the sub hopper is cleaned to make an injection molding different from the above injection molding material. The material is stored in the sub hopper, and then, when the main hopper is emptied by the injection molding material therein being supplied to the injection cylinder of the injection molding machine, the inside of the main hopper is cleaned to remove the sub hopper. Since the injection molding material is supplied to the main hopper, the sub hopper can be cleaned without waiting until the main hopper is empty, that is, the time required for cleaning can be reduced to half. Therefore, it is possible to reduce the molding cycle time and make the injection molding equipment compact.

[Brief description of drawings]

FIG. 1 is a flow chart for explaining an automatic material changing method according to an embodiment of the present invention in an injection molding facility, and FIG. 2 is a schematic configuration diagram of the injection molding facility. 1 ... Injection cylinder, 3 ... Injection molding machine, 4 ... Main hopper, 11
… Vice hopper.

Claims (1)

[Claims] 1. An injection system comprising: a sub-hopper for stocking a predetermined amount of injection molding material; and a main hopper connected to the sub-hopper for supplying the injection molding material stocked in the sub-hopper to an injection cylinder of an injection molding machine. An automatic material changing method in a molding facility, wherein during injection molding supplying an injection molding material in the main hopper to an injection cylinder of the injection molding machine,
When the sub hopper is emptied by stopping the supply of the injection molding material to the sub hopper to change the material, the inside of the sub hopper is cleaned to store an injection molding material different from the above injection molding material in the sub hopper. Then, when the injection molding material inside the main hopper is supplied to the injection cylinder of the injection molding machine and becomes empty, the inside of the main hopper is cleaned to remove the injection molding material inside the sub hopper. An automatic material change method in an injection molding facility characterized by supplying to a hopper.