JP2514992Y2 - Sizing die for extrusion molding equipment - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sizing die for extrusion molding equipment.

[0002]

2. Description of the Related Art Conventionally, a sizing die for an extrusion molding apparatus has a sizing sleeve attached to the inlet of a cooling tank and an elastic sealant attached to the outlet of the cooling tank, as described in JP-A-54-127467. The synthetic resin pipe in a softened state extruded from the extrusion die is cooled while being formed into a regular pipe shape while passing through the sizing sleeve and inside the cooling tank.
It came out from the outlet sealed with the elastic sealing material.

The outlet of this cooling tank is sealed with a flat elastic seal material.

[0004]

However, by using such a conventional sizing die, the softened synthetic resin pipe is passed through the sizing sleeve and passed through the cooling tank to be formed into a regular pipe shape. If so, the synthetic resin pipe that has come out of the sizing sleeve is still in a softened state, so there is a problem that the synthetic resin pipe is crushed and deformed inward by the pressure in the cooling tank.

That is, if the cooling tank is a water tank, the synthetic resin pipe is deformed inward by this water pressure, and the cooling tank sprinkles mist-like cooling water on the outer peripheral surface of the synthetic resin pipe. In the case of the device, the pressure of the cooling water sprinkled increases the atmospheric pressure in the cooling tank and deforms the synthetic resin pipe body. Furthermore,
When the cooling tank is of the so-called vacuum type, in the conventional flat elastic seal material, this seal material is
It was deformed and drawn into the tank, making it difficult to maintain a negative pressure.

Therefore, an object of the present invention is to prevent the synthetic resin pipe body from being crushed and deformed while passing through the cooling tank,
An object of the present invention is to provide an extrusion-molding sizing die capable of forming a beautiful tube shape.

[0007]

The present invention has been made to solve the above problems and achieve the above objects. A sizing sleeve is attached to the cooling tank inlet and an elastic sealing material is provided at the cooling tank outlet. Attached,
While the synthetic resin tube in the softened state extruded from the extrusion die is passing through the sizing sleeve and passing through the cooling tank, it is cooled while being shaped into a regular tube shape and sealed with an elastic sealing material. In the sizing die for the extrusion molding apparatus that exits from the exit, the elastic sealing material protrudes outward in a conical shape from the peripheral edge of the cooling tank exit, and a through hole that is not larger than the outer diameter of the synthetic resin pipe body is provided at the tip. , This cone
-Like elastic sealant is applied from the peripheral edge of the cooling tank outlet to the through hole
It is a straight line without being bent toward the inside , and the inside of the cooling tank is kept at a negative pressure.

[0008]

The sizing die of the present invention is a vacuum type that is cooled while the outer surface of the softened synthetic resin tube extruded from the extrusion die slides on the inner surface of the sizing sleeve and is shaped into a regular tube shape. In this case, after it is sufficiently cooled and solidified, it exits from an outlet sealed with an elastic sealing material.

At this time, since the cooling tank has a negative pressure, the softened synthetic resin tube is not crushed and deformed by the water pressure or the atmospheric pressure in the cooling tank. The outer peripheral surface is in close contact with the sizing sleeve and is shaped into a regular tube.

If a negative pressure is applied to the inside of the cooling tank in this way,
In the conventional sizing die for the extrusion molding apparatus, the elastic seal material at the outlet is deformed inward as described above, a gap is generated between the elastic seal material and the synthetic resin tube, and the seal is incomplete, in this invention, from the periphery of the cooling tank outlet the elastic seal member protrudes outward conically, the tip through-holes not greater than the outer diameter of the synthetic resin tube is provided ,, conical
-Like elastic sealant is applied from the peripheral edge of the cooling tank outlet to the through hole
Since Ru straight der without being bent towards and sealed airtightly with the tip of the outer peripheral elastic sealing material of this hole synthetic resin tube. And when the negative pressure in the cooling tank,
Work force protrusion to deform in the opposite direction than the projection direction, the leading end of the elastic sealing member further adhered to the synthetic resin tube, seal Ri completely and Do, the synthetic resin tube is the elastic sealing member
It is taken out smoothly from the tip of.

[0011]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 shows an embodiment of the present invention, and is a cross-sectional view showing a main part in a state where a synthetic resin tube is shaped and cooled by using a sizing die.

FIG. 2 shows another embodiment of the present invention.
It is sectional drawing which shows the principal part in the state which has shaped and cooled the synthetic resin pipe body using a sizing die. In FIG.
Reference numeral 1 is a synthetic resin tubular body extruded from an extrusion die provided at the tip of an extruder (not shown).

Reference numeral 2 is a sizing die. The sizing die 2 is composed of a cooling type cooling tank 22 and a sizing sleeve 21 provided at the inlet of the cooling tank 22.
The inner surface of the sizing sleeve 21 serves as the shaping surface 23 of the synthetic resin pipe body.

Further, the spraying device 3 is provided inside the cooling tank 22.
Is provided. In the cooling tank 22, cooling water is sprinkled from the sprinkling device 3 onto the outer surface of the sizing sleeve 21 and the surface of the synthetic resin pipe body 1 to cool the sizing sleeve 21 and the synthetic resin pipe body 1.

Reference numeral 4 denotes an outlet of the cooling tank 22, and this outlet 4
Is a through hole larger than the outer diameter of the synthetic resin tube 1. 41 is a peripheral portion of the outlet 4 of the cooling tank 22.

Reference numeral 5 denotes an elastic seal material made of synthetic rubber. The elastic seal material 5 is attached to the peripheral edge portion 41 of the outlet 4 of the cooling tank 22, projects outward in the cooling tank 22 in a conical shape, and has a tip end. The portion is provided with a through hole that is slightly smaller than the outer diameter of the synthetic resin tube body 1, and is curved toward the through hole at the tip.
It is straight without.

Reference numeral 6 denotes a suction port, through which air in the cooling tank 22 is sucked, and the inside of the cooling tank 22 has a negative pressure. Next, a method of shaping a synthetic resin tubular body using this device will be described.

Synthetic resin tube 1 extruded from an extrusion die
Enters the sizing die 2. Then, the outer peripheral surface of the synthetic resin tubular body 1 slides on the shaping surface 23 of the inner surface of the sizing sleeve 21 provided at the inlet of the cooling tank 22 and is cooled while being shaped into a regular tubular shape. .

After the synthetic resin tube 1 has passed through the sizing sleeve 21, it enters the cooling tank 22, where the cooling water 31 is directly sprinkled on the outer peripheral surface of the synthetic resin tube 1 to be cooled and completely solidified. To do.

At this time, the inside of the cooling tank 22 has a negative pressure because the air inside the cooling tank 22 is sucked from the suction port 6.
Therefore, the synthetic resin tubular body 1 is subjected to a force that expands outwardly, comes into close contact with the sizing sleeve 21, is shaped into a regular tubular shape, and is cooled.

In this way, the synthetic resin tube 1 is shaped into a regular tube while being cooled and solidified, so that it has a beautiful tube shape. When the synthetic resin pipe body 1 becomes a regular pipe shape in this way, it exits from the outlet 4 of the cooling tank 22.

At this time, there is an elastic seal member 5 at the outlet 4 of the cooling tank 22, and the synthetic resin pipe 1 is slightly smaller than the outer diameter of the synthetic resin pipe 1 provided at the tip of the elastic seal member 5. Exit through the passage. Therefore, the outer peripheral surface of the synthetic resin tube 1 and the tip of the elastic sealing material 5 are in close contact with each other and are airtight. Further, since the inside of the cooling tank 22 has a negative pressure, the elastic seal material 5 is projected in the shape of a cone in the outer direction of the tank, and therefore tends to be deformed in the direction opposite to the projecting direction. The tip of the through hole 5 further closely adheres to the outer peripheral surface of the synthetic resin tube body 1 to complete the seal at this portion. However, the elastic seal material 5 bends toward the through hole at the tip.
The elastic seal material 5 cools because it is straight without being damaged.
Due to the negative pressure inside the tank 22, the outer circumference of the synthetic resin tube 1 is excessively increased.
If it is pressed against the surface, it will hinder the progress of the synthetic resin tube 1.
Not.

Next, another embodiment shown in FIG. 2 will be described. In the embodiment shown in FIG. 2, an annular projection 51 having a semicircular cross section is formed on the outer peripheral surface of the elastic sealing member 5a protruding in a conical shape.
Are concentric with the central axis of the cone.

When such a ridge 51 is provided, the through hole provided at the tip of the elastic seal material 5a is less likely to be deformed from a perfect circle, and the through hole is less likely to be larger, so that the synthetic resin pipe This is preferable because the adhesion to the body 1 is improved and moreover, even if the inside of the sizing die 2 becomes a vacuum, it is difficult to deform inward. The ridges 51 may be provided on the inner surface or both surfaces of the elastic sealing material 5a, and the number thereof may be plural. Further, the protrusion 51 is not limited to the annular shape, and may be, for example, a spiral shape or a zigzag shape.

Others have the same structure as the embodiment shown in FIG. 1 and are used in the same manner.

[0026]

As can be seen from the above description, the sizing die according to the present invention has a negative pressure inside the cooling tank, so that the softened synthetic resin tube is pushed by the water pressure or atmospheric pressure inside the cooling tank. Without being crushed, it is shaped into a regular tube shape, and a beautiful synthetic resin tube can be manufactured.

Further, since a sealing material protruding outwardly in a conical shape is provided at the outlet of the cooling tank, the elastic seal does not become incomplete even if the pressure inside the cooling tank is negative. Rather, since the seal is complete, the inside of the cooling tank can be kept in a stable negative pressure state. In this case, the sealing material is the tip of the
Elastic because it is straight without being curved toward the through hole
The sealing material 5 is excessively synthesized due to the negative pressure inside the cooling tank 22.
The synthetic resin tube 1 advances as it is pressed against the outer peripheral surface of the resin tube 1.
It does not cause any problems.

Further, it is convenient to provide a ridge on the front surface or the back surface of the conical elastic sealing member so as to be concentric with the center line of the cone, so that the sealing becomes more complete.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, and is a cross-sectional view showing a main part of a sizing die of the present invention in a state where a synthetic resin tube is extruded.

FIG. 2 is a cross-sectional view showing a main part of a state in which a synthetic resin tubular body is extruded by using another sizing die of the present invention.

[Explanation of symbols]

 1 Synthetic Resin Pipe 2 Sizing Die 21 Sizing Sleeve 22 Cooling Tank 23 Shaped Surface 4 Cooling Tank Outlet 41 Peripheral Edge of Cooling Tank Outlet 5, 5a Elastic Seal Material

Claims (2)

(57) [Scope of utility model registration request] 1. A sizing sleeve is attached to the inlet of the cooling tank, and an elastic sealing material is attached to the outlet of the cooling tank. A softened synthetic resin tube extruded from an extrusion die is provided. In the sizing die for the extrusion molding apparatus, which is cooled while being formed into a regular pipe shape while passing through the cooling tank through the sizing sleeve and is sealed with the elastic sealing material, the elastic sealing material is protrudes from the periphery of the cooling tank outlet conically outwardly, the tip is provided with through holes not greater than the outer diameter of the synthetic resin tube, the conical elastic sealing member periphery of the cooling bath outlet
Straight from the part to the through hole at the tip
There is a negative pressure inside the cooling tank, which is a sizing die for an extrusion molding apparatus. 2. The elastic sealing material protrudes outward in a conical shape, and a projection is provided on the front surface or the back surface of the cone concentrically with the center line of the cone.
A sizing die for the extrusion molding apparatus described.