JP3254382B2 - Extrusion mold structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a die structure of an extrusion die suitable for manufacturing wind molding and the like.

[0002]

2. Description of the Related Art When a molded article is made of two kinds of constituent materials by extrusion molding or the like, a partition wall may be provided at a die portion. This is a measure to prevent the two types of resin extruded from the die lip from mixing with each other at the boundary. Therefore, in the case where the whole is formed of the same material,
It is unnecessary to provide a partition such as a partition wall in the die part,
Such a partition was naturally not found in the mold structure of the conventional extrusion mold.

[0003]

By the way, the applicant of the present invention operates a slider for changing the shape of a deformed shape, in particular, the shape of a die outlet, so that the shape of a molded product to be extruded changes in the longitudinal direction. (See Japanese Patent Application Laid-Open No. 5-138714). And
In such extrusion dies, it has recently been found that changes in the shape of the die outlet have a negative effect on product quality.
For example, if the shape of the die exit is changed by the first slider and the second slider described in the above-mentioned publication, the shape other than the portion to be changed should be affected even to the shape that should be constant, and wrinkles on the design surface etc. And so on. The movement amount of the resin molded product at the die exit and the flow rate from the extruder become inconsistent due to the movement of the first slider and the second slider, and the error applies pressure to the entire molten resin passing through the die, causing a shape defect. Is given. FIG.
In another example, the slider 91 is moved, and FIG.
From the side shape 92 of (a), the upper shape 9 of (b)
When it is changed to 3, the angle R and the height H, which should originally be constant, are also changed.

The present invention has been made to solve the above problems, and provides an extrusion molding die structure in which the shape change is kept within a certain range when the slider is moved by variable molding, and the influence on the whole is minimized. The purpose is to:

[0005]

In order to achieve the above object,
The gist of the invention according to claim 1 is an extrusion mold for molding a variable molding made entirely of the same material,
Guide section where molten resin is continuously extruded from the extruder
The forming plates for the variable part and the invariable part
The top surface of the superposed forming plate
Form a constant part die exit and a variable part die exit on the surface
At the same time, a slider is provided on the outside of the die exit so as to move forward and backward.
The variable die exit is changed by the movement of the slider,
And the molten resin from the molding plate to the die outlet
In the flow path, the plate-shaped rectifying plate is provided in a boundary area between the molten resin facing the exit of the variable portion die and the molten resin facing the exit of the constant portion die.
Erect and fixed on the forming plate, and the current plate is fixed
Characterized by leaving a gap between the
Extrusion mold .

According to the first aspect of the present invention, a molding preform is provided.
In the flow path of the molten resin from the heat sink to the die outlet,
Molten resin toward the outlet of the b
A plate-shaped current plate is placed on the forming plate at the boundary area between
When fixed, the flow rate of molten resin toward the exit of the die
Even if the pressure changes, the swash plate suppresses the spread of the molten resin toward the outlet of the unchanged portion die. Current plate can be invariable
Instead of completely separating the variable part, the constant part and the variable part
Between the slider movements
Inconveniences such as displacement of invariable parts will not occur
You.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the mold structure of the extrusion mold of the present invention will be described in detail. FIGS. 1 to 4 show an embodiment of a die structure of an extrusion die according to the present invention, which is applied to an extrusion die for wind molding. FIG. 1 is a front view showing a main part of the extrusion mold, FIG. 2 is a cross-sectional view taken along line IV-IV of FIG.
FIG. 4 is a front view showing an operation change state of the first slider and the second slider, and FIG. 4 is a change view of an extruded product.

[0008] The molded article 1 obtained by the die structure of the extrusion mold of the present invention changes from a side rain gutter shape as shown in FIG. 4A to an upper shape (C) through an intermediate shape (B). And continuously changed. The molded article 1 is composed of a leg 11, a head 12, and a lip 13. Here, it is intended to obtain a molded article 1 which is a variable molding in which only the shape of the leg 11 changes. In addition, the surface of the head 12 is a design surface 12a, and reference numeral 14 denotes a co-pressed bright foil.

Next, a description will be given of a mold structure of an extrusion mold for producing the molded article 1. A known extruder (not shown) for continuously extruding the molten resin Y is installed on the right side of FIG. 2, and after the guide portion 2 is attached, the first molding plate 3 to the third molding The plate 5 is fixed. The first molding plate 3 mainly guides the head 12 of the molded product 1, and the second molding plate 4 additionally guides the leg 11. The third forming plate 5 further guides the lip portion 13, and the tip end surface of the third forming plate 5 is a die exit surface 51. The molten resin Y made of the same material flows out of the extruder, and a single flow to the head 12 is formed on the first molding plate 3. In addition, a flow to the leg portion 11 is formed by the second forming plate 4, and a flow of the lip portion 13 is formed by the third forming plate 5.

A first slider 6 and a second slider 7 are provided at the die exit E so as to be able to move forward and backward (FIGS. 1 and 2). The first slider 6 and the second slider 7 move in the direction of the arrow, and gradually change the area of the die exit E to change the shape of the leg 11 from the side shape of FIG. It can be changed to a part shape. In addition, it is possible to return to the side part shape by the reverse movement. The first slider 6 slides vertically outside the die exit E to change the length from the longest side rain gutter shape to the smallest upper shape. The first slider 6 defines a lower shape of the variable molding (molded product) and has a hook portion 61 forming a window glass fitting portion. Further, the second slider 7 slides in the substantially horizontal direction outside the die exit E,
The first slider 6 is retracted from the side portion shape forming the notch portion, instead of the side portion shape, and can be shifted to the upper portion shape. These first slider 6 and the movement of the second slide 7, the die exit E of the leg portion 11 becomes the variable portion die outlet E ₁ varies while the die exit E of the head 12 and the lip 13, the When the first slider 6 and the second slider 7 move, they do not change.
_{It is 2} (Fig. 3).

Then, in the flow path of the molten resin Y, the molten resin Y ₂ and the invariable part die E ₂ directed toward the variable part die outlet E _1.
A current plate 8 is provided in a boundary region between the molten resins Y ₁ and Y 3 facing the flow path. Here, a rectifying plate 81 that separates the leg 11 and the head 12, and a rectifying plate 82 that separates the leg 11 and the lip 13
There is. The rectifying plates 81 and 82 are literally plate-shaped, and are erected and fixed to the first forming plate 3, and the front ends thereof are close to the die exit surface 51. However, the tip 8a of the current plate 8 is
Although it differs slightly depending on the product shape and the mold structure, it is retracted toward the extruder main body in a range of a length of 1/3 to 2/3 times the thickness t of the third forming plate which is the frontmost forming plate from the die exit surface 51. However, it is preferable to provide it at the location (FIG. 2). If the tip 8a of the current plate 8 is too close to the die exit surface 51, the molten resins Y ₁ , Y ₂ , and Y separated by the current plate 8 are formed.
₃ becomes difficult to join at the die exit, while the tip 8
If the distance a is too far from the die exit surface 51, it is meaningless to provide the straightening plate 8, and the flow rate change and the pressure change in the variable portion are affected even to the invariable portion. In FIG. 1, the positions of the rectifying plates 81 and 82 viewed from the front are drawn for confirmation, and a molded product 1 in which these portions are buried is completed as a matter of course. Current plate 8
As shown in FIG. 2, a plate may be attached, or a buildup may be formed on the first molding plate 3. The thickness of the current plate 8 is preferably set as thin as possible while maintaining the mechanical strength. The rectifying plate 8 literally promotes the rectifying action of the molten resin Y, but if it is too thick, it becomes a baffle plate. For example, in this embodiment,
The thickness of the current plate is set in the range of 0.4 mm to 1.0 mm.

By providing the above-mentioned current plate 8,
In the flow path of the molten resin Y, the flow of the molten resin Y1, Y2, Y3 forming the head 12, the leg 11, and the lip 13 is more completed. The molten resin Y1 on the head 12
In the flow, the first slider 6 and the second slider 7 do not enter and the shape does not change. However, the molten resin Y1 in this portion is well guided to the straight portion die exit E2 by the guide of the current plate 81. And go. Similarly, where the shape of the lip portion 13 does not change, the molten resin Y3 in this portion also receives the guidance of the rectifying plate 82 and heads toward the invariable portion die exit E2.
On the other hand, the shape of the leg portion 11 is being changed by the movement of the first slider 6 and the second slider 7. Even if the molten resin Y2 in this portion receives the flow rate fluctuation and the pressure fluctuation due to the shape change, it is stopped by the rectifying plate 8, so that it does not transmit to the molten resin Y1 and Y3 but to the variable portion die exit E1. Become. That is, as the cross section of the die exit changes in the first slider 6 and the second slider 7, the flow of the molten resin Y2 changes in the molding plate, and also affects and changes the shape of the invariable portion. But
Rectifier plates 81 and 82 suppress the fluctuation propagation of pressure and flow from the variable portion to the invariable portion.

By the way, each of the rectifying plates 81 and 82 does not completely separate the invariable portion (the head portion 12 and the lip portion 13) from the variable portion (the leg portion 11). The gap S is left. In order to prevent the invariable portion from being affected by the pressure due to the change in the shape of the variable portion, it is originally desirable that the invariable portion be completely partitioned by the current plate 8. However, for example, when the current plate completely separates the boundary area between the variable portion and the invariable portion, when the second slider 7 moves, the shape must be as shown in FIG. In some cases. Further, if the flow straightening plate 8 is connected without providing the gap S, it becomes inconvenient to make a mold or to cope with a correction in a trial. The other components are basically the same as the mold structure of a normal molding die, and the description thereof is omitted.

In the structure of the extrusion die thus configured, the shape defect of the head 12 forming the design surface 12a is reduced, and the quality of the molded product 1 can be stabilized. In the conventional extrusion molds, sinks, misalignments, and whitening defects of the head 12 were frequently caused by the movement of the first slider 6 and the second slider 7. Problems have been greatly improved. The lip portion 13 also secured a stable shape. This is the first slider 6,
Even if the flow of the molten resin Y is different between the invariable part and the variable part due to the movement of the second slider 7, the difference is directed to the die exit direction by the rectifying plate 8, It is said that the influence is reduced. Further, even if there is a change in the flow of the molten resin Y _{2 due to} the movement of the first slider 6 and the second slider 7, the change is contained in the variable portion divided by the rectifying plate 8, which is important in quality. It is said that the design surface 12a and the like are not affected. In the production of the variable molding, the product is easily affected by the pressure change and the difference in the flow rate of the molten resin Y, and also easily affected by the variation of each extruder for extruding the molten resin Y in each part. However, these are effectively reduced by providing the current plate 8. This is because each flow path of the molten resin cannot enter another flow path beyond the flow path due to the presence of the current plate 8.

The present invention is not limited to the embodiment described above, but can be variously modified within the scope of the present invention depending on the purpose and application. The shape, size, and the like of the first slider 6, the second slider 7, the current plate 8, the die exit E, and the like can be appropriately selected according to the application.

[0016]

As described above, the die structure of the extrusion molding die of the present invention has a structure in which wrinkles and other defects are less likely to appear on the design surface or the like even in the case of variable molding whose shape changes in the longitudinal direction. Therefore, it exerts an excellent effect on maintaining stable quality.

[Brief description of the drawings]

FIG. 1 is a front view showing a main part of an extrusion mold in one embodiment of a method for attaching a skin according to the present invention.

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

FIG. 3 is a front view showing an operation change state of a first slider and a second slider.

FIG. 4 is a change diagram of an extruded product.

FIG. 5 is an explanatory front view of a conventional technique.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Variable molding (molded article) 11 Leg part (variable part) 12 Head part (invariant part) 13 Lip part (invariant part) 3 First molding plate (molding preform for invariable part)
4 ) Second forming plate (forming part for variable part )
5 ) Third forming plate (Molding plate for constant part )
51 ) Die exit surface 6 First slider (slider) 7 Second slider (slider) 8, 81, 82 Rectifier plate E Die exit E1 Variable portion die exit E2 Invariant portion die exit S Gap t Third forming plate thickness ( Front row molding plate)

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-338523 (JP, A) JP-A-9-136342 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29C 47/00-47/96

Claims (1)

(57) [Claims] 1. A whole is in the extrusion molding die for molding a variable molding of the same material, solvent from the extruder
For the variable section of the guide section where the molten resin is continuously extruded, unchanged
Laminate and fix the molding plates for
Use the tip of the formed plate as the die exit
B) and an exit of the variable die.
A slider is provided on the outside of the mouth so that it can move forward and backward, and
The die exit of the variable part is changed by
In the flow path of the molten resin from the rate to the die outlet, a plate-shaped rectifying plate is formed on the molding plate in a boundary region between the molten resin toward the variable part die outlet and the molten resin toward the invariable part die outlet.
It is fixed upright, and the rectifying plate has a gap between the invariable part and the variable part.
A die structure of an extrusion die, which is arranged so as to leave a gap.