JPH0478451B2 - - Google Patents

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention provides a two-way injection molding machine with a T-shaped nozzle that enables sandwich molding, blow molding, foam molding, and single molding using a single twin-screw injection molding machine. Regarding axial injection molding machines.

[Conventional technology]

Conventionally, the T-shaped nozzles that are connected to the two injection units of a twin-screw injection molding machine include the following (a) and (b).
Such things are known.

(a) The inner nozzle, which is arranged concentrically within the outer nozzle and is slidable in the axial direction, is made rotatable by a rotating means, and the rotation of the inner nozzle opens and closes the resin passage, and the inner nozzle An actuating rod for opening and closing the nozzle hole of the inner nozzle is provided inside (Japanese Unexamined Patent Publication No. 59-220341).

(b) An annular insert arranged concentrically within the injection head is provided so as to be slidable in the axial direction, and a needle having a connecting passage is provided within the annular insert so as to be freely rotatable, and by rotating the needle. The connection passage is constructed so that gas can be supplied by opening and closing the connection passage (Japanese Patent Application Laid-open No.
(See Publication No. 94805).

[Problem to be solved by the invention]

In all of the above conventional techniques, the nozzle hole opening/closing mechanism is complicated and a plurality of drive devices are provided, so that the control of opening/closing the nozzle hole is also complicated. Furthermore, since it was developed for Santotsuchi molding, it is impossible to perform single molding using only one axis, and since the nozzle hole of the outer nozzle is opened and closed by sliding the inner cylinder (or annular insert), each shot must be Another problem was that stringing of the molten resin from the nozzle hole occurred, and it was difficult to make the diameter of the T-shaped nozzle too small from the viewpoint of strength.

The present invention has been made in view of the above-mentioned problems of the conventional technology, and it is possible to perform sandwich molding, blow molding, foam molding, and single molding with one molding machine, and to reduce the stringiness of each shot. It is an object of the present invention to provide a twin-screw injection molding machine having a T-shaped nozzle with a simple structure that can prevent the above problems.

[Means to solve the problem]

In order to achieve the above object, the two-axis injection molding machine of the present invention connects a T-shaped nozzle body to a first injection unit and a second injection unit through a shut-off mechanism, and a tip portion in the T-shaped nozzle body. At the same time, an annular outer torpedo is fitted to the rear end of the T-shaped nozzle body, and a cylindrical valve ring disposed inside the T-shaped nozzle body is connected to the rear end to connect the inner peripheral surface of the T-shaped nozzle and the outer peripheral surface of the valve housing. an outer passage is formed between the valve housing, a shaft reciprocated by a reciprocating drive means is inserted into the valve housing to form an inner passage between the two, and the shaft is slidably guided on the inner circumferential surface of the outer torpedo. an inner torpedo is fixed to the tip of the shaft, a boss portion of the outer and inner torpedo is provided with a tip sealing surface and a rear end sealing portion, and gas supply ports are provided in each of the two connecting portions of the T-shaped nozzle body. .

Furthermore, it is effective to configure the T-shaped nozzle body so that it can be disassembled into a plurality of parts.

[Effect]

When molding is performed using the twin-shaft injection molding machine having the T-shaped nozzle of the present invention, the reciprocating drive device is first activated to move the inner torpedo to a predetermined intermediate position via the shaft, and both the outer passage and the inner passage are opened. The state is communicated with the nozzle hole. Next, the molten synthetic resin is injected into the mold by press-fitting the resin into the outer passage and the inner passage from both injection units to perform sandwich molding. In this case, by controlling the position of the inner torpedo, a stable skin layer can be formed by controlling the flow rate of the molten synthetic resin flowing out from the outer passage and the inner passage to the nozzle hole.

Further, the inner torpedo is retracted to the most retracted position by the reciprocating drive device, and with the inner passage closed by the rear end seal portion of the inner torpedo, the molten synthetic resin is press-fitted into the outer passage from the first injection unit. Single molding is performed by injecting into a mold.

Furthermore, by operating the reciprocating drive device, the inner torpedo is moved to a predetermined intermediate position via the shaft, the outer passage and the inner passage are both opened and communicated with the nozzle hole, and the first injection unit or the second injection unit is opened. Either one of the units is closed by its shaft-off mechanism. Then, blow molding or foam molding is performed by injecting the molten synthetic resin into the mold from one injection unit that is open, and pressurizing gas through the gas supply port on the injection unit side that is closed by the other shut-off mechanism. Let's do it.

〔Example〕

Embodiments of the present invention will be described based on the drawings.

As shown in FIGS. 1 and 2, a first injection unit 1 and a second injection unit 2 are arranged side by side on a moving table (not shown), and each head 1a, 2b of both injection units 1, 2 has a are each provided with a shut-off mechanism such as shut-off valves 3 and 4. On the other hand, the T-shaped nozzle body 5 has a base portion 5a having connecting portions 16 and 17 protruding from both sides.
and a distal end portion 5b which is removably connected to the base portion 5a with a bolt or the like (not shown),
A nozzle tip 6 having a nozzle hole 6a is removably fixed to the front opening of the tip 5b. Then, the flange member 1 of one connecting portion 16
6a to the flange member 1b of the head 1a of the first injection unit 1, and the flange member 17a of the other connecting part 17 to the head 2a of the second injection unit 2.
flange member 2b.

Further, an annular outer torpedo 7 is fitted into the tip portion of the T-shaped nozzle body 5, and a cylindrical valve housing 11 is disposed concentrically within the T-shaped nozzle body 5 at its rear end. An outer passage 12 is formed between the inner peripheral surface of the T-shaped nozzle body 5 and the outer peripheral surface of the valve housing 11.
Furthermore, a shaft 9 is inserted into the valve housing 11 and is reciprocated by a reciprocating drive means consisting of a hydraulic cylinder 10 attached to the rear end surface etc. and a piston 10a provided inside the shaft 9. An inner passage 13 is formed between the inner circumferential surface of shaft 9 and the outer circumferential surface of shaft 9 . An inner torpedo 8 is fixed to the tip of the shaft 9, and the inner torpedo 8 is guided by the large diameter portion 7b of the inner peripheral surface of the outer torpedo 7 and is reciprocated in the axial direction via the shaft 9. Ru.

Furthermore, the outer torpedo 7 has a plurality of through holes 7a formed at intervals in the circumferential direction and passing through in the axial direction, and the outer passage 12 and the nozzle hole 6a are connected through the through holes 7a. communicated, while
The inner torpedo 8 has a plurality of through holes 8d formed at intervals in the circumferential direction and passing through in the axial direction, and the inner passage 13 and the nozzle hole 6a are communicated through the through holes 8d.

Note that instead of providing the large diameter portion 7b on the inner circumferential surface of the outer torpedo 7 described above, the inner circumferential surface of the outer torpedo 7 has a large diameter over the entire length, and the inner torpedo 8
The inner passage 13 may be closed by forming a sealing annular protrusion on the inner circumferential surface of the inner circumferential surface of the inner circumferential surface of the inner passageway 13 to which the sealing portion 8c is abutted. Further, the cross-sectional shape of the through holes 7a and 8d of both torpedoes 7 and 8 is not limited to the circular shape shown in the figure, but can be made into various shapes.

Next, the operation of this embodiment will be explained.

First, for sandwich forming, the piston 10a in the hydraulic cylinder 10 shown in FIG. The torpedo 8 is moved to a predetermined intermediate position where both the outer passage 12 and the inner passage 13 are open. Next, the first injection unit 1 injects the molten synthetic resin for forming the skin layer into the outer passage 12.
When the molten synthetic resin for forming the core layer is press-injected into the inner passage 13 from the second injection unit 2, the two merge at the nozzle 6a to form a layered flow and are injected into a mold (not shown) to form a sandwich. products can be molded.

Next, for single molding, only the shutoff valve 3 or 4 of either the first injection unit 1 or the second injection unit 2 is opened,
Although the other shutoff valve is closed, a case will be described here in which, for example, only the shutoff valve 3 of the first injection unit 1 is opened and single molding is performed by the first injection unit 1.

Piston 10 of hydraulic cylinder 10 shown in FIG.
By applying hydraulic pressure to the inner torpedo 8 and moving it backward, the inner torpedo 8 is moved back to the most retracted position via the shaft 9, as shown in FIG. In this state, the outer passage 12 from the first injection unit 1
When the molten synthetic resin is press-fitted inside, the molten synthetic resin passes through each through hole 7a of the outer torpedo 7 and is injected from the nozzle hole 6a into a mold (not shown) to perform single molding.

Furthermore, as in the case of sandwich molding, the inner torpedo 8 is moved to a predetermined intermediate position as shown in FIG.
Either the first injection unit 1 or the second injection unit 2 is closed by closing the shutoff valve 3 or 4. Then, the molten synthetic resin is press-fitted into the mold through one open injection unit, and the gas is press-fitted through the gas supply port on the other side, which is closed, resulting in blow molding or foam molding. Do this.

〔Effect of the invention〕

Since the present invention is configured as described above,
This produces the effects described below.

The twin-shaft injection molding machine having a T-shaped nozzle according to claim 1 has a simple structure in which only the inner torpedo moves back and forth, so it is superior in strength and can be used for sandwich molding, single molding, hollow molding and foam molding. It is possible to perform various types of molding, and a single machine has the same benefits as installing several dedicated machines, making it possible to significantly reduce equipment costs.

In addition to the above effects, the twin-screw injection molding machine having the T-shaped nozzle according to claim 2 can be disassembled for easy inspection or cleaning.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the main part of the T-shaped nozzle of the present invention,
2 is a sectional view taken along line A-A in FIG.
are diagrams each showing the most retracted position. 1...First injection unit, 2...Second injection unit, 3, 4...Shaft off valve, 5...T
Shape nozzle body, 5a... base, 5b... tip,
6... Nozzle chip, 6a... Nozzle hole, 7...
Outer torpedo, 7a...Through hole, 7b...Large diameter part, 8...Inner torpedo, 8a...Boss part, 8
b...Tip sealing surface, 8c...Rear end sealing part, 8
d...Through hole, 9...Shaft, 10...Hydraulic cylinder, 10a...Piston, 11...Valve housing, 12...Outer passage, 13...Inner passage, 14, 15...Gas supply port, 16 ,17...
Connection portions 1a, 1b, 16a, 17a...flange members.

Claims (1)

[Scope of Claims] 1 T is connected to the first injection unit 1 and the second injection unit 2 via shut-off mechanisms 3 and 4, respectively.
The T-shaped nozzle body 5 is connected to the T-shaped nozzle body 5, and an annular outer torpedo 7 is fitted to the distal end portion of the T-shaped nozzle body 5, and a cylindrical valve is disposed within the T-shaped nozzle body 5 at its rear end. The housing 11 is connected to form an outer passage 12 between the inner circumferential surface of the T-shaped nozzle body 5 and the outer circumferential surface of the valve housing 11. A shaft 9 is inserted to form an inner passage 13 between the two, and an inner torpedo 8 that is slidably guided on the inner peripheral surface of the outer torpedo 7 is fixed to the tip of the shaft. The boss portion 8a is provided with a tip sealing surface 8b and a rear end sealing portion 8c, and the two connecting portions 16 of the T-shaped nozzle body 5,
17 with gas supply ports 14 and 15, respectively.
Two-screw injection molding machine with shaped nozzle. 2. The biaxial injection molding machine with a T-shaped nozzle according to claim 1, wherein the T-shaped nozzle main body 5 can be disassembled into a plurality of parts.