JP3514739B2 - Resin heating device in extrusion molding equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin heating device in an extrusion molding device equipped with a heater for heating a die from the inside.

[0002]

2. Description of the Related Art An extrusion molding apparatus is usually constructed as follows.

That is, the extrusion molding apparatus is equipped with an extruder for extruding a resin which has been heated and melted, and a die for passing the resin extruded from the extruder to form a tubular shaped article. A die main body having a die hole that opens forward in the resin extrusion direction, a mandrel fitted in the die hole having an axis extending in the front-rear direction, and an inner peripheral surface of the die main body. A mandrel having a cylindrical molding void formed between the outer peripheral surface of the mandrel and having its front end opened forward, and a heater attached to the outer surface of the die for heating the resin passing through the molding void. There is.

Then, when the resin that has been heated and melted is extruded and supplied toward the molding cavity by the extruder, the resin passes through the molding cavity, whereby a tubular shaped article is continuously molded. The molded product is continuously extruded forward from the front part of the die.

In the above case, the heater heats the resin in the molding cavity and maintains the resin in an appropriate molten state so as to make it into the tubular shape.

Further, conventionally, there is an extrusion molding apparatus provided with a processing machine for processing a molded product extruded from the front part of a die into a predetermined shape. This processing machine is provided at the front part of the die. It is located near the outer surface.

[0007]

By the way, in the above-mentioned conventional technique, since the processing machine is arranged near the outer surface of the front part of the die, the front part of the die is avoided in order to avoid interference with the processing machine. It is not easy to attach a large-capacity and large-shape heater to the outer surface of the die.Therefore, when the processing machine is installed as described above, it is possible to make the resin in the front part of the die into an appropriate molten state. It can be difficult.

The present invention has been made in view of the above circumstances, and a processing machine for processing a molded product extruded from the front part of a die into a predetermined shape is arranged near the outer surface of the front part of the die. Or in the case of trying to secure a wider working space in the vicinity of the outer surface of the front part of the die, even if it is not easy to attach a large capacity heater to the outer surface of the front part of the die, An object of the present invention is to make a resin passing through the front part of the die into a predetermined molten state.

[0009]

The resin heating device in the extrusion molding apparatus of the present invention for solving the above problems is as follows.

According to the first aspect of the invention, the resin 2 which is melted by heating is used.
An extruder 3 for extruding a resin, and a die 5 for molding a tubular shaped article 4 by passing the resin 2 extruded from the extruder 3.
And a die body 10 having a die hole 9 that is open toward the front in the extrusion direction of the resin 2.
A mandrel 11 having a shaft center 8 extending in the front-rear direction and fitted into the die hole 9, and a front end formed between the inner peripheral surface of the die body 10 and the outer peripheral surface of the mandrel 11. In the resin heating device in the extrusion molding device, which includes a cylindrical molding void 12 that opens toward the front,

The die 5 has a fitting hole 21 formed inside the mandrel 11 and located on the axis 8 of the mandrel 11, and is fitted into the fitting hole 21 to heat at least the front portion of the mandrel 11. the heater 22 to be formed,

[0012] the outer surface near the front 15 of the upper Symbol die 5 and the da
(A) A molded product 4 arranged so as to straddle the vicinity of the front of the die 5 and immediately after being extruded forward from the front portion 15 of the die 5.
Processing machine 3 that sequentially processes the bellows shape with this extrusion
It is equipped with 0.

According to a second aspect of the present invention, in addition to the first aspect of the present invention, the fitting hole 21 is opened toward the rear of the die 5, and the heater is inserted into the fitting hole 21 from the rear of the die 5. 22 is removably inserted.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

In the figure, reference numeral 1 is an extrusion molding apparatus, and the extrusion molding apparatus 1 passes through an extruder 3 that pressurizes and extrudes a heat-melted thermoplastic resin 2 and a resin 2 extruded from the extruder 3. Thus, a tubular shaped article 4 is continuously formed, and a die 5 for continuously extruding forward is provided.

The arrow Fr in the figure indicates the resin 2 formed by the die 5.
It shows the front of the extrusion direction.

The die 5 has a die body 10 having a die hole 9 which is open toward the front in the extruding direction of the resin 2 and has a shaft center 8 extending in the front-rear direction, and the die hole 9 on the shaft center 8 in the die hole 9. A mandrel 11 to be fitted is provided, and a cylindrical molding space 12 formed between the inner peripheral surface of the die hole 9 and the outer peripheral surface of the mandrel 11 and having a front end opening forward.

The molding void 12 is formed in the rear portion 1 of the die 5.
3, a multi-layered rear space 14 having a shape of a truncated cone that is tapered toward the front, and a cylinder formed in the front part 15 of the die 5 and having substantially the same cross-sectional shape and size at each axial portion. And a front void 16 in the shape of.

The outer diameter of the front end of the rear space 14 and the outer diameter of the front space 16 are substantially the same.
The front end of the rear space 14 is communicated with the rear end of the front space 16, and the front end of the front space 16 is open toward the front of the die 5. Further, the front portion of the die body 10 which constitutes the front portion 15 of the die 5 is a pipe-shaped body 17 having a circular cross section and located on the axis 8.

A heater 19 for heating the rear portion 13 from the outer surface side thereof is attached to the outer surface of the rear portion 13 of the die 5, and the pipe-shaped body 17 of the die body 10 which is the front portion 15 of the die 5 is attached. A linear heater 20 for heating the front portion 15 from the outer surface side thereof is attached to the outer peripheral surface of the coil in a coil shape.

The die 5 is formed inside the mandrel 11 and is located on the axis 8 of the mandrel 11 and penetrates the mandrel 11 in the front-rear direction.
1 is fitted into the fitting hole 21 on the shaft center 8,
A rod-shaped heater 22 that heats the die 5 from the inside is provided.

The fitting hole 21 is formed in the rear portion 13 of the die 5.
A large diameter hole 23 formed in the rear part of the mandrel 11 and having a rear end opening rearward of the die 5,
The mandrel 11 forming the front part 15 of the die 5 has a rear end communicating with the front end of the large-diameter hole 23, while the front end of the mandrel 11 communicates with the front end of the large-diameter hole 23. It has and.

On the other hand, the heater 22 has the fitting hole 2
The large-diameter portion 25 fitted into the large-diameter hole 23 and the small-diameter portion 26 integrally molded with the large-diameter portion 25 and fitted into the small-diameter hole 24 of the fitting hole 21 are provided. Is removably fitted into the fitting hole 21 from the rear of the die 5.

In the above case, the heater 20 attached to the outer peripheral surface of the pipe-shaped body 17 has a small capacity, and the heater 20 largely projects radially outward from the outer peripheral surface of the pipe-shaped body 17. Is prevented. The heater 22 fitted in the fitting hole 21 of the mandrel 11 compensates for the insufficient capacity of the heater 20 on the outer peripheral surface of the pipe-shaped body 17.

A processing machine 30 is provided for sequentially processing the uncured molded product 4 extruded from the front part 15 of the die 5 into a product 29 having a predetermined shape and curing the product 29. The processing machine 30 constitutes the extrusion molding device 1,
It is arranged so as to straddle the vicinity of the outer surface of the pipe-shaped body 17 which is the front portion 15 of the die 5 and the vicinity of the front of the die 5, and in the illustrated example, the product 29 has a bellows shape.

The processing machine 30 is provided with a pair of endless belt type rotation mechanisms 31, 31 located above and below the molded product 4 immediately after being extruded forward from the die 5. Each of these rotating mechanisms 31 includes a frame 32 disposed above and below the molded product 4, and a pair of front and rear rotating wheels 33, 33 rotatably supported by the frame 32 about their respective axes.
And the endless belt 3 wound around these rotating wheels 33, 33.
4 and a plurality of mold blocks 35 attached to the endless belt 34 along the longitudinal direction thereof.

By driving the rotating mechanism 31, the endless belt 3 is
4 rotates in the longitudinal direction thereof, and accordingly, the group of mold blocks 35 on the side of the molded product 4 among the large number of mold blocks 35 moves forward together with the molded product 4.

When the extrusion molding apparatus 1 is used to mold the product 29 having the predetermined shape, first, the resin 2 heated and melted by the extruder 3 is extruded toward the molding gap 12 of the die 5. Supply. Then, the resin 2 passes through the molding gap 12 to continuously mold the tubular shaped product 4, and the molded product 4 is continuously extruded forward from the front portion 15 of the die 5. Be done.

In the above case, the heater 19 for heating the rear portion 13 of the die 5 and the large-diameter portion 25 which is the rear portion of the heater 22 in the mandrel 11 are the resin in the rear void 14 which is the upstream side of the molding void 12. 2 and heat this resin 2
Is maintained in an appropriate molten state so as to have the above tube shape. Also, a heater 20 for heating the front portion 15 of the die 5
And the small diameter portion 26 which is the front portion of the heater 22 in the mandrel 11 heats the resin 2 in the front void 16 which is the downstream side of the molding void 12, and the resin 2 is predetermined by the processing machine 30. It is maintained in an appropriate molten state so that it can be shaped.

When the molded product 4 is pushed forward from the front portion 15 of the die 5, the mold block 35 group of each rotating mechanism 31 of the processing machine 30 driven drives the molded product 4 to the diameter thereof. It is sandwiched one after another from the outside in the direction, and in the sandwiched state, it moves forward together with the molded product 4. Then, during the sandwiching, the molded product 4 is sequentially processed into a predetermined shape and cured, so that the predetermined product 2 is obtained.
9 is molded.

According to the above construction, the resin 2 which has been heated and melted
An extruder 3 for extruding a resin, and a die 5 for molding a tubular shaped article 4 by passing the resin 2 extruded from the extruder 3.
And a die body 10 having a die hole 9 that is open toward the front in the extrusion direction of the resin 2.
A mandrel 11 having a shaft center 8 extending in the front-rear direction and fitted into the die hole 9, and a front end formed between the inner peripheral surface of the die body 10 and the outer peripheral surface of the mandrel 11. In the resin heating device in the extrusion molding device, which includes a cylindrical molding void 12 that opens toward the front,

The die 5 has a fitting hole 21 formed inside the mandrel 11 and located on the axis 8 of the mandrel 11, and is fitted into the fitting hole 21 to heat at least the front part of the mandrel 11. A heater 22 is provided to operate.

Therefore, even if a heater having a large capacity and a large shape is not attached to the outer surface of the front portion 15 of the die 5, the front portion of the die 5 can be provided by the heater 22 in the fitting hole 21 of the mandrel 11. 15 is fully heated.

Therefore, in the case where the processing machine 30 is arranged near the outer surface of the front portion 15 of the die 5 or a wider working space is secured, the front portion 1 of the die 5 is
Even when it is not easy to attach the heater 20 having a large capacity and a large shape to the outer surface of the die 5, the heater 22 in the fitting hole 21 of the mandrel 11 allows the resin 2 passing through the front portion 15 of the die 5 to be predetermined. Can be brought into a molten state. As a result, when the molded product 4 made of the resin 2 is to be processed immediately thereafter to form the product 29 having a predetermined shape, this processing is achieved more reliably.

Further, as described above, the front portion 15 of the die 5 is
A molding machine 30 is provided which is disposed near the outer surface of the die 5 and which sequentially extrudes the molded product 4 extruded forward from the front part 15 of the die 5 into a predetermined shape in accordance with the extrusion.

For this reason, the molded product 4 is transferred to the processing machine 30.
If you want to make it into a predetermined shape by
0 becomes a large size, and this large-sized processing machine 30 occupies the space near the outer surface of the front portion 15 of the die 5, and thus,
Even if the heater 20 attached to the outer surface of the front portion 15 of the die 5 has to be made small, the heater 22 in the fitting hole 21 of the mandrel 11 causes the die 5 to move.
The resin 2 that passes through the front portion 15 of is heated to a predetermined molten state.

Therefore, the molded product 4 made of the resin 2 can be made into the product 29 having a predetermined shape by the processing machine 30.

Further, as described above, the fitting hole 21 is opened toward the rear of the die 5, and the heater 22 is fitted into the fitting hole 21 from the rear of the die 5 so as to be removable. .

Therefore, the fitting hole 2 of the mandrel 11 is provided.
Operations such as replacing the heater 22 in 1 with a new one can be easily performed without being disturbed by the processing machine 30.

Although the above is based on the illustrated example, the heater 20 on the outer surface of the front portion 15 of the die 5 may be omitted.

[0041]

The effects of the present invention are as follows.

The invention according to claim 1 is provided with an extruder for extruding a resin which has been heated and melted, and a die for passing the resin extruded from the extruder to form a tubular shaped article. A die main body having a die hole that opens forward in the resin extrusion direction, a mandrel fitted in the die hole having an axis extending in the front-rear direction, and an inner peripheral surface of the die main body. In a resin heating device in an extrusion molding device, which is molded between the outer peripheral surface of the mandrel and has a cylindrical molding void whose front end is open toward the front,

The die has a fitting hole formed inside the mandrel and located on the axis of the mandrel.
A heater is provided which is fitted in the fitting hole and heats at least the front part of the mandrel.

Therefore, even if a heater having a large capacity and a large shape is not attached to the outer surface of the front portion of the die, the front portion of the die can be sufficiently heated by the heater in the fitting hole of the mandrel. .

Therefore, when a processing machine is arranged near the outer surface of the front portion of the die or a wider working space is to be secured, the outer surface of the front portion of the die has a large capacity. Even if it is not easy to attach a heater having a large shape, the resin passing through the front portion of the die can be brought into a predetermined molten state by the heater inside the fitting hole of the mandrel. As a result, when a molded product made of this resin is to be processed immediately thereafter to obtain a product having a predetermined shape, this processing is achieved more reliably.

[0046] Also, the outer surface near the front portion of the die and the da
It is provided so as to straddle the vicinity of the front of the die, and is provided with a processing machine that sequentially processes the molded product immediately after being extruded from the front part of the die to the bellows shape with the extrusion.

Therefore, from the front of the die to the front.
When the molded product immediately after being extruded is made to have a bellows shape by the processing machine, the processing machine becomes large and the front side of the die is made by the large processing machine. The space in the vicinity of the outer surface of the die is occupied, and even if the heater attached to the outer surface of the front portion of the die is forced to be small, the heater in the fitting hole of the mandrel passes through the front portion of the die. The resin is brought into a predetermined molten state.

Therefore, the molded product made of the resin can be made into a bellows-shaped product having a predetermined shape by the processing machine.

According to a second aspect of the invention, the fitting hole is opened toward the rear of the die, and the heater is removably fitted into the fitting hole from the rear of the die.

Therefore, the operation of replacing the heater in the fitting hole of the mandrel with a new one can be easily carried out without being disturbed by the processing machine.

[Brief description of drawings]

FIG. 1 is a partially enlarged partial sectional view of FIG.

FIG. 2 is an overall side view of an extrusion molding device.

[Explanation of symbols]

1 Extrusion molding device 2 resin 3 extruder 4 molded products 5 dies 8 axis 9 die holes 10 die body 11 Mandrel 12 Molding void 13 rear 15 front 21 Fitting hole 22 heater 29 products 30 processing machines

Claims (2)

(57) [Claims] 1. An extruder for extruding a resin that has been heated and melted, and a die for passing a resin extruded from the extruder to form a tubular shaped article, the die being in the extrusion direction of the resin. Of the die body having a die hole opening toward the front, a mandrel having an axis extending in the front-rear direction and fitted into the die hole, an inner peripheral surface of the die body and an outer peripheral surface of the mandrel. In a resin heating apparatus in an extrusion molding apparatus having a tubular molding cavity having a front end that opens toward the front, the die is molded inside the mandrel, and the axial center of the mandrel is formed. comprising a fitting hole which is located above is fitted into the fitting hole provided with a heater for heating at least a front portion of said mandrel, extend over the front near the front of the outer surface near the aforementioned die above Symbol die
Arranged so that, the resin heated at press-molded unit having a processing machine for processing the molded article immediately after extruded toward the forward sequential bellows <br/> shape with the extrusion from the front of the die apparatus. 2. The extrusion molding apparatus according to claim 1, wherein the fitting hole is opened toward the rear of the die, and the heater is removably fitted into the fitting hole from the rear of the die. Resin heating device.