KR101285371B1 - Method for filling balance of family mold using valve gate hot runner system - Google Patents

Abstract

The present invention relates to a filling balancing method of an injection molding family mold using a valve gate type hot runner system, and more particularly, an injection resin injected into a plurality of cavities having different volumes and shapes of the family mold. When it reaches the molding end of the cavity, the cavity temperature sensor attached to the molding end of each cavity detects this and sends a charging completion signal to the control amplifier installed outside of the family mold, and the control amplifier that detects this signal is a valve installed in each cavity. It transmits the opening and closing signal to the sequence control for automatic control to control the device, and closes it first from the gate of the cavity where charging is completed first, and repeats this process, and when the resin filling of all the cavity provided in the family mold is completed, the gate of all the cavity is completed. Open the box at the same time It is possible to make a balanced filling and continuous injection molding operation for a plurality of cavities having different volumes and shapes during injection molding of family molds, thereby ensuring high quality without defects of unmolding or overlap caused by filling imbalance. The present invention relates to a charging and balancing method of a family mold for injection molding using a valve gate type hot runner system that enables a large quantity of product to be mass-produced.

Description

Method for filling balance of family mold using valve gate hot runner system}

The present invention enables a balanced filling and continuous injection molding operation for a plurality of cavities having different volumes and shapes during injection molding of a family mold, thereby providing high quality without defects of unmolding or overlap caused by filling imbalance. The present invention relates to a charging and balancing method of a family mold for injection molding using a valve gate type hot runner system that can greatly increase productivity by enabling mass production of family products.

In general, injection molding means that a synthetic resin in the form of powder or pellets is poured into an injection cylinder equipped with a heating device, melted, and then pressed into a cavity of an injection mold using a transfer screw installed in the injection cylinder, followed by cooling and curing. It is widely used to mass-produce a product made of a synthetic resin, in particular, to mold a desired product.

The injection molds used in the injection molding are classified into single cavity mold, multi cavity mold, and family mold according to the number of cavities. Among them, family mold ) Is equipped with a plurality of cavities having different volumes and shapes in one mold, and can simultaneously produce a plurality of plastic parts required to assemble a product in one injection molding operation.

In general, in order to injection molding a plurality of plastic parts required to assemble one product (for example, 10 to 20 plastic parts are required for a vacuum cleaner product), a mold suitable for each part needs to be manufactured. In this case, as the number of molds increases, the cost of manufacturing the mold increases, as well as the injection molding machine requires as many molds as the number of molds, and the investment and maintenance cost of the injection molding machine increases. .

Therefore, when a family mold having a plurality of cavities having different volumes and shapes in one mold is manufactured without separately manufacturing a mold for each part, it is necessary to assemble one product in one injection molding operation. Since it is possible to produce multiple plastic parts at the same time, not only can greatly reduce mold production and maintenance costs, but also many injection molding machines are not required even during injection molding operations. You can save.

On the other hand, the injection molding machine used in the injection molding is injection molding to apply a heat to the flow portion of the synthetic resin from the injection cylinder to the plurality of cavities provided in the injection mold to maintain the molten state of the synthetic resin passing through the resin flow path The injection molding hot runner system includes an open gate hot runner system in which the gate is always open and a valve gate type hot runner system that can open and close the gate. In the furnace, the application of the valve gate hot runner system is spreading more widely than the open gate hot runner system.

In the conventional injection-molded valve gate type hot runner system, as shown in FIG. 1, a resin flow passage 31 is formed inside a branch of one inflow end to a plurality of outflow ends, and a peripheral portion of the resin flow path 31 is formed. The heater 32 is provided with a manifold block 30 is installed, the inlet end of the manifold block 30 is provided with a sprue bush 33 is formed with a resin inlet 33a therein, A plurality of outlet end portions of the manifold block 30 are each provided with a resin inlet 34a and a hot runner nozzle 34 provided with a heater 35 on an outer circumferential surface thereof. A fixing mounting plate 36 for fixing the sprue bush 33 is installed in the upper portion with a spacer block 37 interposed therebetween, and the piston is inserted into the fixing mounting plate 36 in the cylinder 37. The valve actuating pin (39) moves up and down by (38) while the hot runner nozzle (34) It is comprised so that the some valve apparatus 40 which opens and closes the resin inlet 34a is provided.

According to the conventional injection molding valve gate type hot runner system configured as described above, the resin inlet 33a of the sprue bush 33 in which the molten synthetic resin supplied from the injection cylinder is coupled to the upper portion of the manifold block 30. A plurality of formed between the upper plate 41a and the lower plate 41b of the family mold 41 via the resin flow path 31 and the hot runner nozzle 34 branched inside the manifold block 30 through While being injected into the two cavities 42, the heater 32 embedded in the manifold block 30 and the heater 35 installed on the outer periphery of the hot runner nozzle 34 are heated to a constant temperature to maintain a molten state. In addition, the plurality of valve devices 40 installed on the fixed mounting plate 36 can open and close the resin inlets 34a of the hot runner nozzle 34 according to the injection signal, thereby allowing the runner to run. : Hardening synthetic resin in resin channel) and hot run Therefore possible to prevent the gate of the solidified developer nozzle is possible to continuous injection molding operation.

However, in the case of performing the injection molding operation by applying the conventional valve gate type hot runner system to the family mold, the plurality of cavities 42 included in the family mold 41 are formed in different volumes and shapes. During molding, there was a problem in that defects such as unmolding or overlapping were frequently generated due to filling imbalance for each cavity 42.

In order to solve this problem, after making the family mold 41, the test injection molding is repeated, and the filling of each cavity 42 provided in the family mold 41 is corrected while modifying the resin inlet reaching each cavity 42. It is a cumbersome mold modification work to balance one by one, and this mold modification work also takes a lot of time and effort because it increases or decreases the resin inlet by a trial and error method according to the volume of each cavity 42. As a result, a secondary problem in which the resin filling speed and the flow balance do not match occurs, thus making it difficult to produce the family mold 41 considering the perfect filling balance for all the cavities 42.

In addition, in the related art, when the injection molding operation using the family mold 41 is interrupted, the gate of the cavity 42, in which defects such as unmolding or overlapping, are blocked, may be performed while taking the trouble of injection molding separately. In this case, the occurrence of defects can be reduced, but there is a problem that the productivity is significantly reduced.

The present invention is to solve the above problems, when the injection resin injected into a plurality of cavities having a different volume and shape provided in the family mold reaches the molding end of each cavity, the cavity mounted on the molding end of each cavity The temperature sensor detects this and sends a charging completion signal to the control amplifier installed outside of the family mold, and the control amplifier which senses this signal transmits an opening / closing signal to the automatic control sequence timer that controls the valve device installed in each cavity to charge it first. By sequentially closing the gate of the completed cavity and repeating this process, when the resin filling of all the cavities provided in the family mold is completed, the gates of all the cavities are configured to open at the same time to carry out the pressure retention process, thereby injecting the family mold. Different volumes and shapes when forming Branches enable balanced filling and continuous injection molding of multiple cavities, enabling mass production of high-quality family products without unformed or overlapped defects caused by filling imbalances, resulting in significant productivity improvements. It is technical problem to do.

Filling and balancing method of the injection molding family mold using the valve gate type hot runner system according to the present invention for achieving the above technical problem is injected into a plurality of cavities having different volumes and shapes provided in the family mold in the injection molding machine Injection using a valve-gate hot runner system configured to open and close the gate of each cavity by operating the valve device according to a control signal while applying heat to the flow of the injection resin so that the injection resin can be kept molten. In the filling balancing method of a molding family mold, when the injection resin injected into a plurality of cavities provided in the family mold reaches the molding end of each cavity, a cavity temperature sensor mounted on the molding end of each cavity detects this; Cavity charge detection step of outputting a charge completion signal, and the cavity In the tee filling detection step, when the charge completion signal output by the cavity temperature sensor mounted on each molding end of the cavity is input to the control amplifier installed outside the family mold, the control amplifier controls the valve device connected to each cavity. Complete the resin charging of all the cavities provided in the family mold through the cavity sequential closing step of closing the sequential order from the gate of the cavity where charging is completed first by transmitting an opening / closing signal to the timer. After the cavity simultaneously opening step to open the gates of all the cavity at the same time, and the pressure holding step to apply a constant injection pressure to all the cavity is opened through the cavity simultaneous opening step.

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According to the filling balancing method of the injection molding family mold using the valve gate type hot runner system according to the present invention configured as described above, in the injection molding of the family mold, the balance filling for a plurality of cavities having different volumes and shapes Since continuous injection molding operation is possible, it is possible to mass-produce high quality family products without defects of unmolding or overlap caused by filling imbalance, thereby greatly improving productivity.

1 is an explanatory view showing a valve gate type hot runner system installed in a conventional injection molding family mold.
Figure 2 is an explanatory view showing a valve gate type hot runner system of the injection molding family mold according to the present invention.
3 is a control block diagram of a valve gate type hot runner system of an injection molding family mold according to the present invention.
Figures 4a to 4e is an explanatory view showing the operating state of the valve gate type hot runner system of the injection molding family mold according to the present invention.
Figure 5 is a block diagram showing a filling balancing method of a family mold using a valve gate type hot runner system according to the present invention.

Hereinafter, the present invention for achieving the above object will be described in detail with reference to FIGS. 2 to 5.

Valve gate type hot runner system of the injection molding family mold used in the present invention has a different volume and shape between the upper plate (2) and the lower plate (3), as shown in FIG. A resin flow passage 6 is formed in the upper portion of the family mold 1 in which the plurality of cavities 4 are formed, which branches one inflow end into the plurality of outflow ends, and a heater 7 is formed in the periphery of the resin flow passage 6. ) Is provided with a manifold block (5) buried.

A sprue bush 8 having a resin inlet 8a formed therein is installed at an inlet end of the manifold block 5, and a resin inlet 9a is formed therein at a plurality of outlet ends, and a heater 10 is formed on an outer circumferential surface thereof. Each hot runner nozzle 9 is installed.

A fixing mounting plate 11 for fixing the sprue bush 8 is installed on the upper portion of the manifold block 5 with the spacer block 12 interposed therebetween. A plurality of valve devices 13 are installed to open and close the resin inlet 9a of the hot runner nozzle 9 while the valve actuating pin 16 is raised and lowered by the piston 15 inserted into the inside of 14).

On the other hand, the molding end of the plurality of cavities (4) provided in the family mold (1) the cavity temperature sensor (17) to detect when the injection resin reaches the molding end of each cavity (4) to output a charging completion signal (17) Are fixedly installed.

At this time, the cavity temperature sensor 17 detects the internal temperature of the cavity 4 in a contact or non-contact manner and outputs an electrical signal proportional thereto.

Outside the family mold (1) is provided with a control amplifier 19 which is connected by a cavity temperature sensor 17 and a connection cable 18 fixed to the molding end of the plurality of cavities (4), respectively, the control amplifier On one side of the output terminal 19 is provided an automatic control sequence timer 20 for controlling the valve device 13 connected to each cavity 4 according to the charging completion signal output by each cavity temperature sensor 17, and the other side. At the output end, a wireless data kit 21 wirelessly connected to the display device 22 displaying the control status of the valve device 13 installed in each cavity 4 is installed.

At this time, the control amplifier 19 amplifies and converts an electrical signal output by each cavity temperature sensor 17 to transmit an open / close signal to the automatic control sequence timer 20.

In addition, the automatic control sequence timer 20 receives an injection signal from the injection molding machine or the control amplifier 19 and transmits an electrical signal to a solenoid valve for controlling the air pressure supplied to the cylinder 14 of each valve device 13. The valve device 13 for opening and closing the resin inlet 9a of the hot runner nozzle 9 is operated.

The operation relationship of the valve gate type hot runner system of the injection molding family mold configured as described above will be described with reference to FIGS. 4A to 4E.

First, as shown in FIG. 4A, when the valve devices 13a, 13b, 13c respectively connected to the cavities 4a, 4b, 4c of the family mold 1 are opened according to the injection signal of the injection molding machine. The resin flow path branched inside the manifold block 5 through the resin inlet 8a of the sprue bush 8, in which the molten synthetic resin supplied from the injection cylinder is installed at the inlet end of the manifold block 5; Cavity 4a formed between the upper plate 2 and the lower plate 3 of the family mold 1 via a hot runner nozzle 9 provided at the outlets of the manifold block 5 and the manifold block 5. (4b) and 4c.

Subsequently, as shown in FIG. 4B, when the injection resin injected into the first cavity 4a having the smallest volume among the cavities provided in the family mold 1 reaches the molding end, the first cavity 4a The cavity temperature sensor 17a mounted at the molding end detects this and sends a charging completion signal to the control amplifier 19 installed outside the family mold 1, and the control amplifier 19 which detects this signal is the first cavity. The gate of the first cavity 4a in which charging is completed is first closed by transmitting an opening / closing signal to the automatic control sequence timer 20 that controls the valve device 13a provided in (4a).

At this time, as the gate of the first cavity 4a is closed by the valve device 13a, the resin filling of the first cavity 4a is stopped, and the second and fourth cavities 4b and 3 which are not yet filled. Resin filling of the cavity 4c continues.

Subsequently, when the injection resin injected into the second cavity 4b having the smallest volume among the cavities provided in the family mold 1 reaches the molding end, as shown in FIG. 4C, the second cavity 4b The cavity temperature sensor 17b mounted at the molding end of the sensing unit senses this and sends a charging completion signal to the control amplifier 19 installed outside the family mold 1, and the control amplifier 19 that detects this signal is a second. The opening and closing signal is transmitted to the automatic sequence controller 20 for controlling the valve device 13b installed in the cavity 4b, thereby closing the gate of the second cavity 4b in which charging is completed.

At this time, as the gate of the second cavity 4b is closed by the valve device 13b, the resin filling of the second cavity 4b is stopped, and the resin filling of the third cavity 4c which has not been filled yet. Continues.

Subsequently, when the injection resin injected into the third cavity 4c having the largest volume among the cavities provided in the family mold 1 reaches the molding end, as shown in FIG. 4D, the third cavity 4c The cavity temperature sensor 17c mounted at the molding end senses this and sends a charging completion signal to the control amplifier 19 installed outside the family mold 1, and the control amplifier 19 which detects this signal is the third cavity. The gate of the third cavity 4c in which charging is completed is closed by transmitting an opening / closing signal to the automatic control sequence timer 20 which controls the valve device 13c provided in 4c.

When the resin filling of the cavities 4a, 4b, 4c provided in the family mold 1 is completed through the above process, the gates of the cavities 4a, 4b, 4c are opened as shown in FIG. 4E. After opening at the same time, pressurizing process is performed to apply a constant injection pressure to the cavities 4a, 4b and 4c, and then the cooling process to close and cool the gates of the cavities 4a, 4b and 4c simultaneously Proceeding to complete the injection molding operation.

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On the other hand, the filling balancing method of the injection molding family mold using the valve-gate hot runner system according to the present invention is the cavity filling detection step 23, the cavity sequential closing step 24, the cavity simultaneously as shown in FIG. It is made through the opening step 25, the holding step 26.

In the cavity filling detection step 23, when the injection resin injected into the plurality of cavities 4 provided in the family mold 1 reaches the molding end of each cavity 4, the molding end of each cavity 4 The cavity temperature sensor 17 mounted in the sensing unit outputs the charging completion signal.

In the cavity sequential closing step 24, the charging completion signal output by the cavity temperature sensor 17 mounted on the molding end of each cavity 4 in the cavity filling detection step 23 is external to the family mold 1. When input to the control amplifier 19 installed in the control amplifier 19, the control amplifier 19 transmits an opening / closing signal to the automatic control sequence timer 20 for controlling the valve device 13 connected to each cavity 4, the cavity which has been completely charged first. The gates of (4) are sequentially closed.

At this time, the resin filling of the cavity 4 closed by the valve device 13 is stopped, and the resin filling of the cavity 4 which has not been filled yet continues.

In the cavity simultaneous opening step 25, the resin filling of all the cavities 4 provided in the family mold 1 is completed through the cavity filling detection step 23 and the cavity sequential closing step 24. The gate of 4) is opened at the same time.

In the holding step 26, a constant injection pressure is applied to all the cavity 4 in which the gate is opened through the cavity simultaneous opening step 25.

According to the filling balancing method of the injection molding family mold using the valve gate type hot runner system according to the present invention configured as described above, the injection molding of the family mold (1) has a plurality of cavities having different volumes and shapes ( 4) Balanced filling and continuous injection molding can be performed, and the productivity can be greatly improved by mass production of high quality family products without defects of unmolding or overlap caused by filling imbalance. .

1 Family mold 2 Senate 3 House of Representatives
4, 4a, 4b, 4c: cavity 5: manifold block 6: resin flow
7 Heater 8 Sprue Bushing 8a Resin Inlet
9: hot runner nozzle 9a: resin inlet 10: heater
11: fixed mounting plate 12: spacer block 13, 13a ~ 13n: valve device
14 Cylinder 15 Piston 16 Valve operating pin
17, 17a ~ 17n: cavity temperature sensor 18: connection cable
19: Control amplifier 20: Sequence timer for automatic control
21: wireless data kit 22: display device
23: Cavity filling detection step 24: Cavity sequential closing step
25: simultaneously opening the cavity 26: holding step

Claims (2)

delete In the injection molding machine, a control signal is applied while heating the flow portion of the injection resin to maintain the molten state of the injection resin injected into the plurality of cavities 4 having different volumes and shapes of the family mold 1. In the filling balancing method of the injection molding family mold using the valve gate type hot runner system configured to operate the valve device 13 to open and close the gate of each cavity 4,
Cavity temperature sensor 17 mounted on the molding end of each cavity 4 when the injection resin injected into the plurality of cavities 4 provided in the family mold 1 reaches the molding end of each cavity 4. Cavity charge detection step (23) to detect this and output a charging completion signal;
In the cavity charge detection step 23, the charging completion signal output by the cavity temperature sensor 17 mounted on the molding end of each cavity 4 is input to the control amplifier 19 installed outside the family mold 1. When the control amplifier 19 transmits an opening / closing signal to the automatic control sequence timer 20 that controls the valve device 13 connected to each cavity 4, the control amplifier 19 sequentially closes the gate of the cavity 4 that has been charged first. Cavity sequential closing step 24,
Through the cavity filling detection step 23 and the cavity sequential closing step 24 to complete the resin filling of all the cavity (4) provided in the family mold (1) to open the gate of all the cavity (4) at the same time Cavity simultaneous opening step 25,
Injection molding family using a valve-gate hot runner system, characterized in that it comprises a pressure holding step 26 to apply a constant injection pressure to all the cavity (4) the gate is opened through the simultaneous opening step (25) of the cavity Fill balancing method of mold.

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