JPH06254943A - Extrusion machine and supply of material to extrusion machine - Google Patents

Abstract

PURPOSE:To ensure that a stable extrusion function is obtained, if the hardness and thickness of a material changes. CONSTITUTION:A feed orifice 3 for feeding a material is provided on the base end part of a cylinder 1. In addition, a screw 2 for transporting the material to the tip by a screw-in action, is provided in the cylinder 1 and is composed of a rotary shaft 6 and a spiral blade 7. The circumferential diameter of the rotary shaft 6 at a position corresponding to the feed orifice 3 of the screw 2 is the same, while the circumferential diameter of the rotary shaft 6 of the spiral blade 6 becomes narrower toward the tip. Under this constitution, if a material which is easily screwed into the cylinder 1 is introduced from its base end side, this feed action is restricted due to the narrow space between the cylinder 1 and the spiral blade 7. Further, if a material which is not easily screwed into the cylinder 1 is introduced from the feed orifice 3 on the tip side of the cylinder 1, the feed action is promoted due to the wide space between the cylinder 1 and the spiral blade 7. Consequently, both materials can always be fed in a stable screw-in quantity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an extruder used for extruding a rubber material.

[0002]

2. Description of the Related Art In the prior art of this type, as shown in FIGS. 3 and 4, a cylinder 20 is formed in a tubular shape, and a rubber material is supplied to a peripheral wall of a base end portion (right portion in FIG. 3) of the cylinder 20. Mouth 21
Is provided. The tape-shaped rubber material cut into pieces is supplied from the supply port 21 to the cylinder 20.
It is continuously introduced in. A screw 24 including a spiral blade 22 and a rotary shaft 23 is provided in the cylinder 20. By the rotation of the screw 24, the rubber material is bitten into the cylinder 20 and sheared,
It is transferred to the tip end side of the cylinder 20 (left part in FIG. 3). A heater (not shown) is provided on the outer periphery of the cylinder 20, and the sheared rubber material is melted by the heat generated by the heater and is extruded from the discharge port 25 and discharged.

[0003]

However, in this conventional extruder, when the thickness or hardness of the rubber material changes, the amount of bite into the cylinder 20 changes. And when the amount of bite of the rubber material increases,
That is, when the rubber material easily bites, the rubber material once bited into the cylinder 20 may flow back to the supply port 21 and accumulate in the supply port 21 as a large amount of banks. In this case, the bank is again screw 2
As a result, the amount of the rubber material discharged from the discharge port 25 becomes unstable by being bitten into the cylinder 20.

Further, when the amount of bite of the rubber material is small, that is, when the rubber material is hard to bite,
The amount of the rubber material discharged from the discharge port 25 decreases, and the discharge flow of the rubber material becomes unstable. In this case, in the conventional extruder, since the supply port 21 is simply wedge-shaped, the supply port 21 is formed depending on the hardness and thickness of the rubber material.
It is necessary to adjust the depth and width of the. Specifically, it is necessary to correct the shape of the supply port 21 or replace the cylinder 20 with the supply port 21 having a different shape, which is very complicated.

The present invention has been made by paying attention to the problems existing in such a conventional technique, and the purpose thereof is to correct the shape of the supply port and replace the cylinder. It is to provide an extruder capable of always ensuring a stable extrusion function.

[0006]

In order to achieve the above object, the invention according to claim 1 provides a supply port for supplying a rubber material, which is provided at a base end portion of a cylinder, and inside the cylinder. A screw that is provided and transfers the rubber material supplied from the supply port to the tip portion of the cylinder by its rotation, and is provided at the tip portion of the cylinder,
An extruder having a discharge port for discharging a rubber material transferred by the screw, in a portion located at the supply port of the screw, the root diameter is substantially the same in any part, The gist of the present invention is to reduce the mountain diameter of the screw toward the base end side.

According to the second aspect of the present invention, a rubber material that is hard to bite is supplied to the supply port on the tip side of the cylinder, and a rubber material that easily bites is supplied to the supply port on the base end side of the cylinder. This is the summary.

[0008]

(Function) Claims 1 and 2 configured as described above
In the invention described in (1), the rubber material is introduced into the cylinder from the supply port, is bitten by the rotation of the screw and is sheared, and is conveyed to the tip along the cylinder, and the rubber material is discharged from the discharge port.

At this time, the rubber material which easily bites is continuously introduced into the supply port on the base end side of the cylinder. With this supply, even with a rubber material that easily bites, the crest diameter of the screw is reduced toward the base end side, so the gap between the screw and the inner side surface of the cylinder is large. Therefore, since the rubber material enters the gap, slippage becomes large and it becomes difficult to bite. Therefore, a large amount of bite does not cause the rubber material once bite into the cylinder to flow back to the supply port. In other words, by suppressing excessive bite of the rubber material that easily bites, a stable bite amount is always secured. As a result, the amount of the rubber material discharged from the discharge port is stably extruded.

Further, the rubber material which is difficult to bite is continuously introduced into the supply port on the tip side of the cylinder. With this supply, even with a rubber material that is difficult to bite, since the screw crest diameter increases toward the tip side, the gap between the screw and the inner side surface of the cylinder is small. Therefore, since the rubber material enters the gap, slippage becomes small and it becomes easy to bite. Therefore, the bank of rubber material retained in the supply port becomes small. The smaller the bank,
The penetration of the rubber material is promoted. In other words, by promoting the bite amount of the rubber material that is difficult to bite, the rubber material also always secures a stable bite amount. As a result, the amount of the rubber material discharged from the discharge port is stably extruded.

[0011]

An embodiment of the present invention will be described below with reference to the drawings. As shown in FIGS. 1 and 2, the cylinder 1
The screw 2 is rotatably arranged therein. Further, a rubber material supply port 3 is formed on the peripheral wall of the base end (right part of the figure) of the cylinder 1, and a discharge port 4 is formed on the tip part (left part of FIG. 2) of the cylinder 1. Has been formed. Further, the supply port 3 is formed so as to be continuous toward the outer circumference of the screw 2, and the length of the supply port 3 along the axial direction of the screw is larger than that of the conventional supply port 21. .

The screw 2 is composed of a rotary shaft 6 and a spiral blade 7 provided around the rotary shaft 6. In the portion of the screw 2 located at the supply port 3, the rotary shaft 6 has the same root diameter in any portion. Further, in this portion, the spiral blade 7 having the mountain diameter of the screw 2 is a reduced diameter portion 7a that is gradually reduced in diameter from the tip to the base end of the spiral blade 7. That is, the clearances L1, L2, L3, and L4 between the reduced diameter portion 7a of the spiral blade 7 and the inner surface of the cylinder 1 increase from the tip to the base (L1 <L2 <L3 <L4.
). Further, the groove portion 8 between the spiral blade 7 and the reduced diameter portion 7a is formed.
Is gradually deeper from the base end to the tip.

Next, the method of supplying the rubber material to the extruder constructed as described above and the operation of the extruder will be described. In this extruder, when the screw 2 is rotated by a motor (not shown), a piece of tape-shaped rubber material is fed from the supply port 3 into the cylinder 1. Then, the rubber material is sheared and plasticized by the rotation of the screw 2 and is transferred to the tip end side along the axis of the cylinder 1 to be extruded from the discharge port 4 and discharged.

At this time, a rubber material having a small amount of bite,
That is, the rubber material that is difficult to bite is supplied from the material supply range α (the left side portion in FIG. 1) of the supply port 3 on the tip side from the vicinity of the center of the rotating shaft 6. With this supply, the rubber material that is difficult to bite is introduced into a deep portion of the bottom of the groove portion 8 of the screw 2. For this reason, even if the rubber material is hard to bite, the groove 8 has a deep bottom, which makes it easy to bite. At the same time, the rubber material, which is difficult to bite, bites into the gaps L1 and L2, so that slippage of the rubber material is reduced. Therefore, the bank of the rubber material staying in the supply port 3 becomes smaller, and as the bank becomes smaller, the rubber material that is hard to bite easily bites into the cylinder 1. In other words, since the amount of bite of the rubber material that is hard to bite is promoted, a stable amount of bite is always ensured, so that the discharge amount does not decrease and is stable.

A rubber material having a large amount of bite, that is, a rubber material which easily bites is supplied from a material supply range β (the right side portion in FIG. 1) of the supply port 3 near the center from the base end of the rotary shaft 6. Along with this supply, the rubber material that easily bites is introduced into a shallow place at the bottom of the groove portion 8 of the screw 2. For this reason, even if the rubber material is easy to bite, it is difficult to bite because the bottom of the groove portion 8 is shallow, and a large amount of biting prevents the rubber material once bited into the cylinder 20 from flowing back to the supply port 21. With that,
Since the rubber material that easily bites into the gaps L3 and L4, slippage of the rubber material increases. That is, a stable bite amount is always ensured by suppressing the bite amount of the rubber material that easily bites.

Therefore, according to the present invention, even when the hardness or thickness of the rubber material is changed, the bite amount can be adjusted by changing the position of supplying from the supply port 3 according to the characteristics of the rubber material. it can. Therefore, the amount of bite does not greatly affect the difference in rubber material. Therefore, it is possible to always secure a stable bite amount of the rubber material without modifying the shape such as the depth of the supply port 3 or replacing the cylinder 1 with the supply port 3 having a different shape. As a result, a stable extrusion function can be exhibited.

The present invention is not limited to the configuration of the above embodiment, and for example, a material supply device for automatically supplying a rubber material may be provided near the supply port 3. The material supply device may be controlled so as to automatically change the supply position to the supply port 3 in accordance with the characteristics of the rubber material. For example, the configuration of each part is within the scope of the present invention. May be arbitrarily changed and embodied.

[0018]

Since the present invention is configured as described above, it has the following excellent effects.

According to the first aspect of the present invention, even if the thickness or hardness of the rubber material changes, it is not necessary to correct the shape of the supply port or replace the cylinder, and the rubber material can be stably supplied at all times. It has an excellent effect that the amount can be secured.

According to the second aspect of the present invention, even if the thickness or hardness of the rubber material is changed, it is not necessary to correct the shape of the supply port or replace the cylinder, and it is possible to match the characteristics of the rubber material. It has an excellent effect that a stable supply amount of the rubber material can be always secured only by changing the supply position.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view of an essential part showing a screw of an extruder.

FIG. 2 is a sectional view showing the entire screw portion of the extruder.

FIG. 3 is a sectional view of a conventional extruder.

4 is a cross-sectional view taken along the line AA of FIG.

[Explanation of symbols]

1 ... Cylinder, 2 ... Screw, 3 ... Supply port, 4 ... Discharge port, 6 ... Rotating shaft, 7 ... Spiral blade

Claims (2)

[Claims] 1. A cylinder (1) is provided at a base end thereof,
A supply port (3) for supplying a rubber material and a tip portion of the cylinder (1) which is provided in the cylinder (1) and supplies the rubber material supplied from the supply port (3) by its rotation. An extruder provided with a screw (2) for transferring to a cylinder, and a discharge port (4) provided at a tip portion of the cylinder (1) for discharging a rubber material transferred by the screw (2). Then, in the portion of the screw (2) located at the supply port (3), the root diameter is set to be substantially the same at any portion, and the peak diameter of the spiral blade (7) is set to that of the rotary shaft (7). An extruder characterized in that the diameter is reduced toward the base end side. 2. A rubber material which is hard to bite into the supply port (3) on the tip side of the cylinder (1) and which easily bites into the supply port (3) on the base end side of the cylinder (1). The method according to claim 1, wherein the material is supplied to the extruder.