JPH06206240A - Filter nozzle device of injection molding machine - Google Patents

Abstract

PURPOSE:To enable a foreign substance to be easily certainly removed by a method wherein in a device in which a filter removing a foreign substance is arranged in a resin passage formed in a nozzle, a bypass passage for the filter is formed, and besides a valve mechanism opening and closing is annexed. CONSTITUTION:Since a needle valve 34 advance to close a bypass passage 32 in injection molding, only a resin passage 28 is formed in a filter nozzle 14. Further, a screw 26 of an injection cylinder 18 functions, and a resin material flows into the resin passage 28 via a cylinder head 20. Further, after passing through a filter 30, the resin material flows into a main passage 28a of a nozzle head 24 and is injected into a metal mold from a tip hole 24a. At that time a large foreign substance in the resin material can not pass through a slit 30a and stays. Besides, since the needle valve 34 retreats to open the bypass passage 32 in non-injection molding, the resin material flows into the bypass passage 32. The foreign substance stayed at that time is also made to flow to the tip hole 24a together with the resin material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter nozzle device in an inline screw type injection molding machine.

[0002]

2. Description of the Related Art In an in-line screw type injection molding machine, generally, a resin material supply section is connected to an injection cylinder,
The resin material is supplied to the mold through the resin flow path formed in the nozzle and the mold runner, and injection molding is performed. However, foreign materials are mixed in the resin material (resin pellet) used for this injection molding. If it does, there will be short circuit defects due to gate clogging, equipment stoppages due to missing due to gate clogging, and appearance defects when passing through the gate.
It is necessary to provide an appropriate foreign matter removing means. In particular,
Since the amount of foreign matter mixed in recycled resin, which has been used more frequently in recent years, is large, it is indispensable to provide means for eliminating foreign matter.

As such foreign matter removing means, (1) a foreign matter is removed from a resin pellet when a resin material is supplied by mounting a magnet or a metal detector on the resin material supply section, and (2) injection. It is known that a filter is mounted in a cylinder, a nozzle, or a mold runner to remove foreign matter from a molten resin in a supply path of a resin material to a mold. Of these, the foreign matter removing means (1) can remove only a limited type of foreign matter (metal), and therefore the foreign matter removing means (2) is currently used.

However, the above-mentioned foreign matter removing means (2) has the following problems. In other words, since the filter is attached to the resin material supply path at a high temperature and a high pressure at the time of injection, it takes a long time to disassemble / attach the filter for cleaning and replacement. In many cases, such as when the filter is significantly clogged, there is a problem that the molding line is stopped for a long time to clean the filter. Further, if the molding is continued with the filter clogged, the flow of the molten resin is interrupted, and the pressure loss thereof makes it impossible to maintain molding with high stability.

On the other hand, in Japanese Unexamined Patent Publication No. 3-140225, a cylindrical filter is attached to the resin flow path in the nozzle, and the resin material passes through the filter from the inner peripheral side to the outer peripheral side. There is disclosed a filter nozzle device provided with a spool that slides so as to take a mode of passing from the outer peripheral side to the inner peripheral side. In this filter nozzle device, the resin material is passed from the inner peripheral side of the filter to the outer peripheral side during normal injection molding, and when the filter is clogged, a jig for spool pressing is attached to the nozzle to change the spool position. As a result, the resin material is passed from the outer peripheral side of the filter to the inner peripheral side thereof to remove foreign matters.

[0006]

However, in the above-described conventional filter nozzle device, the resin material passage direction of the filter is reversed between the normal injection molding and the foreign matter removal, so that the nozzle structure is improved. Is complicated, and a jig needs to be attached to the nozzle every time foreign matter is removed.

The present invention has been made in view of the above circumstances, and it is possible to eliminate foreign substances from a resin material supply path without requiring disassembly / removal work of an injection molding machine. An object of the present invention is to provide a filter nozzle device for an injection molding machine, which can realize this with a simple structure and without requiring an extra operation.

[0008]

A filter nozzle device for an injection molding machine according to the present invention is provided with a predetermined bypass passage and a valve mechanism for opening and closing the bypass passage in conjunction with the operation of the injection molding machine. The above-mentioned objects are achieved.

That is, as described in claim 1, a resin flow path for guiding the resin material supplied from the injection cylinder to the tip hole of the nozzle is formed inside the nozzle provided at the front end of the injection cylinder. At the same time, a cylindrical filter for removing foreign matters contained in the resin material is mounted in the resin flow passage so as to pass the resin material from the inner peripheral side to the outer peripheral side of the filter. In the filter nozzle device of the injection molding machine, the bypass flow path for guiding the resin material supplied to the inner peripheral side of the filter of the resin flow path to the tip hole without passing through the filter. And a valve mechanism that closes the bypass flow passage during injection molding and opens the bypass flow passage during non-injection molding in conjunction with the operation of the injection molding machine. Are, it is characterized in.

The above-mentioned "opening of the bypass flow path during non-injection molding" is usually performed by cleaning the mold once or for more than one day, or by restarting after injection molding is interrupted due to a product type change or the like. Although it is performed in conjunction with the resin purging operation for removing the stagnant resin, it may be performed in each cycle of injection molding or every several cycles as long as it is in conjunction with the operation of the injection molding machine.

[0011]

As described above, the nozzle has a bypass passage for guiding the resin material supplied to the inner peripheral side of the filter of the resin passage to the nozzle tip hole without passing through the filter. This bypass flow passage is configured to close during injection molding by the valve mechanism in conjunction with the operation of the injection molding machine, and to open during non-injection molding. Even if the filter is clogged with foreign matter contained in the resin material that has passed from the outer circumference to the outer peripheral side, the foreign matter can be guided to the tip hole of the nozzle and easily discharged to the outside during non-injection molding by switching the resin supply path. it can.

Since the above-mentioned valve mechanism only needs to perform a simple operation of opening and closing the bypass passage, it can be easily constructed. Further, since the opening and closing of the bypass flow path by this valve mechanism is performed in conjunction with the operation of the injection molding machine, it is not necessary to attach a jig to the nozzle every time foreign matter is removed.

Therefore, according to the present invention, it is possible to remove foreign matter from the resin material supply path without disassembling / removing the injection molding machine, and with a simple structure and extra work. Can be realized without the need for. Then, since the pressure loss in the filter nozzle device due to the foreign matter can be suppressed on average, molding with high stability can be performed. Further, it is possible to improve the operating rate of the molding line with a low-cost filter nozzle device.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a side sectional view showing a first embodiment of a filter nozzle device of an injection molding machine according to the present invention.

As shown in FIG. 1A, the filter nozzle device 12 is an in-line screw type injection molding machine 10.
The filter nozzle 14 and the valve mechanism 16 are provided.

The filter nozzle 14 has an injection cylinder 18
A filter housing 22 having a cylindrical shape attached to the cylinder head 20 and a nozzle head 24 attached to the front end of the filter housing 22. A resin flow path 28 that guides the resin material (molten resin) supplied by the operation of the screw 26 of the cylinder 18 to the tip hole 24 a of the nozzle head 24 is formed.

A cylindrical filter 30 for removing foreign matters contained in the resin material passes through the resin passage 28 from the inner peripheral side to the outer peripheral side of the filter 30. Is installed. This filter 30
The slits 30a are formed at three locations in the axial direction of the. As shown in FIG. 2, the slits 30a at each of these locations are formed in a radial pattern, and as shown in FIG. 3, the slits 30a are formed such that the inner peripheral portion of the filter is much narrower (gap m). Therefore, when the foreign matter contained in the resin material is larger than the gap m, the foreign matter is prevented from passing through the slit 30a.

As shown in FIG. 1, the nozzle head 24
The main flow passage 28a forming a part of the resin flow passage 28 and the bypass flow passage 32 for guiding the resin material supplied to the inner peripheral side of the filter of the resin flow passage 28 to the tip hole 24a without passing through the filter 30. And are formed.

The valve mechanism 16 includes a needle valve 34 supported by the cylinder head 22 so as to be movable back and forth, an operating lever 36 for moving the needle valve 34 back and forth, and an operating lever 36 for operating the injection molding machine 10. The driving means (not shown) for interlocking and swinging. That is, the valve mechanism 16 advances the needle valve 34 to close the bypass passage 32 during injection molding, as shown in FIG. 1A, while the valve mechanism 16 during non-injection molding, as shown in FIG.
The needle valve 34 is retracted to open the bypass passage 32.

The drive means can be constituted by, for example, a hydraulic cylinder and a shaft, and a standard mechanism used for a shutoff nozzle mechanism of an injection molding machine can be diverted.

Next, the operation of this embodiment will be described.

As shown in FIG. 1A, at the time of injection molding, the needle valve 34 advances to close the bypass flow passage 32, which causes the resin flow passage 28 in the filter nozzle 14.
Only formed. Further, during injection molding, the nozzle head 24 comes into contact with a mold (not shown). Then, the resin material flows into the resin flow path 28 via the cylinder head 20 by the operation of the screw 26 of the injection cylinder 18. The resin material that has flowed into the resin flow path 28 passes through the resin flow path 28 from the inner peripheral side to the outer peripheral side of the filter 30 in the filter housing 22, and then flows into the main flow path 28a of the nozzle head 24 and reaches the tip hole 24a. It is guided and injected into the mold through the tip hole 24a. In the resin flow path 28, when the resin material passes from the inner peripheral side to the outer peripheral side of the filter 30, a gap m among foreign matters contained in the resin material
Larger foreign matter cannot pass through the slit 30a and stays at the inner peripheral side end of the slit 30a.

During non-injection molding, the needle valve 34 retracts to open the bypass passage 32. At this time, the nozzle head 24 is released from the contact state with the mold, and the following foreign matter removing operation is performed.

That is, the operation of the screw 26 of the injection cylinder 18 causes the resin material to flow into the resin flow path 28 via the cylinder head 20. The resin material that has flowed into the resin flow passage 28 advances straight along the inner peripheral side of the filter having a small flow resistance in the filter housing 22, flows into the bypass flow passage 32, and is guided to the tip hole 24 a of the nozzle head 24. At that time, the slit 30a is formed during the injection molding.
The foreign matter that cannot pass through the slit 30a and remains at the inner peripheral side end of the slit 30a is also guided to the tip hole 24a together with the resin material. Since the nozzle head 24 is released from the contact state with the mold, the resin material containing the foreign matter is discharged to the outside from the tip hole 24a.

The gap m on the inner peripheral side of the filter 30 of the slit 30a is set according to the die diameter of the die, especially when the prevention of the gate clogging failure of the die is emphasized. May be set to about m = 0.3 mm to 0.5 mm. Further, when the resin material passes through the filter 30, a pressure loss is caused by its flow resistance, but by appropriately adjusting the number and length of the slits 30a,
This can be minimized.

As described above in detail, in this embodiment, even if the filter 30 is clogged with foreign matter contained in the resin material that has passed from the inner peripheral side to the outer peripheral side of the filter 30 during injection molding, the injection is performed. By switching the resin supply path after molding, this foreign substance can be discharged to the outside without being injected into the mold.

Since the valve mechanism 16 only needs to perform a simple operation of opening and closing the bypass passage 32, it can be easily constructed. Further, since the opening and closing of the bypass flow path by the valve mechanism 16 is performed in conjunction with the operation of releasing the nozzle head from the injection molding machine 10 and the resin purging operation, a jig is attached to the nozzle 14 every time foreign matter is removed. There is no need to do.

Therefore, according to the present embodiment, it is possible to remove foreign matter from the resin material supply path without disassembling / removing the injection molding machine 10, and with a simple structure and extra space. It can be realized without requiring any special work. Then, by this, the pressure loss in the filter nozzle device 12 due to the foreign matter can be suppressed on average, so that highly stable molding can be performed. Also,
A low cost filter nozzle device can improve the operation rate of the molding line.

In this embodiment, the slit 30
Although the filter function of the filter 30 is obtained by a, the filter function may be obtained by a small hole having a circular cross section instead of the slit 30a.

Next, a second embodiment of the present invention will be described.

As shown in FIG. 4, the filter nozzle device 112 according to the embodiment is replaced with the valve mechanism 16 including the needle valve 34 of the first embodiment, and is a nozzle supported by a filter housing 122 so as to be movable back and forth. A valve mechanism 116 having a head 124 is used.

When the nozzle head 124 comes into contact with the mold during injection molding, the nozzle head 124 retracts inside the filter housing 122 due to this contact pressure, and the back surface thereof comes into close contact with the front end surface of the filter 130. In the resin flow path 128, the resin material is allowed to pass from the inner peripheral side to the outer peripheral side of the filter 130.

On the other hand, after the injection molding, the resin flow path 12 is released in a state where the contact between the nozzle head 124 and the mold is released.
When the resin material flows into the nozzle 8, the nozzle head 124 is released from the close contact with the filter 130 by the pressure of the resin material, and the inside of the filter housing 122 is stopped by the stopper 13.
Move forward until it touches 8. As a result, the bypass flow passage 132 is formed in the nozzle head 124 to guide the resin material supplied to the inner peripheral side of the filter of the resin flow passage 128 to the tip hole 124a without passing through the filter 130. .

The slit 130a of the filter 130
Has the same configuration as that of the first embodiment.

Next, the operation of this embodiment will be described.

Also in this embodiment, as in the first embodiment, even if the filter 130 is clogged by foreign matter contained in the resin material that has passed from the inner peripheral side to the outer peripheral side of the filter 130 during injection molding, the injection molding is performed. The effect of being able to discharge this foreign substance to the outside without injecting it into the mold by switching the resin supply path later is provided. However, the valve mechanism 116 in this embodiment has the nozzle head 124 and the mold. Since the valve function is obtained by utilizing the contact pressure and the pressure of the resin material, the above effect can be obtained with a simpler configuration.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a first embodiment of a filter nozzle device of an injection molding machine according to the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

3 is a partially enlarged view of the filter shown in FIG.

FIG. 4 is a side sectional view showing a second embodiment of the filter nozzle device of the injection molding machine according to the present invention.

[Explanation of symbols]

 10, 110 Injection molding machine 12, 112 Filter nozzle device 14, 114 Filter nozzle (nozzle) 16, 116 Valve mechanism 18, 118 Injection cylinder 20, 120 Cylinder head 22, 122 Filter housing 24, 124 Nozzle head 24a, 124a Tip hole 28, 128 Resin flow path 30, 130 Filter 30a, 130a Slit 32, 132a Bypass flow path 34 Needle valve 36 Actuating lever 138 Stopper

Claims (1)

[Claims] 1. A resin flow passage for guiding a resin material supplied from the injection cylinder to a tip hole of the nozzle is formed inside a nozzle provided at a front end portion of the injection cylinder, and in the resin flow passage. A filter of an injection molding machine, in which a cylindrical filter for removing foreign matter contained in the resin material is mounted so as to pass the resin material from the inner peripheral side to the outer peripheral side of the filter. In the nozzle device, a bypass flow path for guiding the resin material supplied to the inner peripheral side of the filter of the resin flow path to the tip hole without passing through the filter is formed in the nozzle, and the injection molding is performed. A valve mechanism is provided which, in conjunction with the operation of the machine, closes the bypass flow passage during injection molding and opens the bypass flow passage during non-injection molding. Filter nozzle device in the form machine.