JPH0741184A - Raw material feeding device and extruder employing the device - Google Patents

Abstract

PURPOSE:To provide a raw material feeding device which is constituted to constantly accurately feed a small amount of a raw material without depending upon the number of revolutions of the screw of an extruder and to provide an extruder employing the raw material feeding device. CONSTITUTION:A raw material feeding device and an extruder employing the device comprise a cylinder body 2 having one end in which an inflow port 21 is formed and the other end in which an outflow port 22 is formed; a raw material feed hopper 3 connected to the inflow port 21; a solid rotary shaft 4 arranged in the cylinder body 2 along a cylinder axis throughout a range of from the inflow port 21 to the outflow port 22; a helical body 5 fixed on the inflow port side of the rotary shaft 4 and expandable over the rotary shaft and feeding a raw material to the outflow port 22 along with rotation; and a drive means 6 to drive the rotary shaft 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a raw material feeding device and an extruder using the same. More specifically, the present invention relates to a raw material feeding device and an extruder that feed a raw material to a raw material input port of an extruder at an appropriate pressure.

[0002]

2. Description of the Related Art Generally, an extruder is mainly composed of an extrusion cylinder having a raw material inlet and a heating means, a screw for rotating the inside of the extrusion cylinder to deliver a raw material, and a drive unit for rotationally driving the screw. There is. In such an extruder,
A raw material hopper is attached to the raw material input port, and the raw material (generally a lot of granular ones) supplied into this raw material hopper corresponds to the decrease in the raw material delivered from the extruder as the screw rotates. It is configured to drop by its own weight and be supplied.

Here, as the screw rotates, the ridges and valleys of the screw alternately pass below the raw material inlet. At this time, the passing speed of the ridges and valleys is high, that is, the screw rotation. If the number is high, the flow of the raw material from the raw material hopper into the extruder will be in a substantially steady state, and on the contrary, if the screw rotation speed is low, the passing speed of the ridges and valleys will be slow, so the passage of the ridges As the raw material does not flow so much at the time and a large amount of the raw material flows at the time of passing through the valley portion, the flow of the raw material from the hopper into the extruder changes. This means that when measuring the inflow of raw material into the extruder by the weight change per unit time, a measurement error will occur if the screw rotation speed is low, but this is because the inflow is controlled to a small level. This is a problem when adding raw materials.

For example, when a color is blended with a molding raw material, the weight of one color grain is very small, and the finished state of the product (particularly the shade of color) is greatly affected by the raw material of one grain. There is a need to. And the input amount of the color itself is one of the molding raw materials to be blended.
As low as ~ 5%, extruding amount during molding is 30kg / h, blending input amount is 2%, color input amount is 600g / h
(= 10 g / min), and assuming that the minimum memory for measurement is 1 g, an error of 1 g may cause a measurement error of 10% when measuring in 1 minute.

Therefore, in the case of molding with a small extrusion amount, the screw rotation speed naturally becomes low. Therefore, when the color is added in this case, the addition amount varies as described above, and the finish of the product becomes uneven. Becomes

[0006]

SUMMARY OF THE INVENTION The present invention relates to a raw material feeding device and an extruder capable of always accurately feeding a small amount of raw material to an extruder regardless of the screw rotation speed of the extruder.

[0007]

Thus, according to the invention of "Claim 1" of the present application, "a cylindrical body (2) having an inflow port (21) at one end and an outflow port (22) at the other end" , Inlet (21) above
A raw material supply hopper (3) connected to, and a solid rotary shaft (4) arranged from the inlet (21) to the outlet (22) along the cylinder axis in the cylinder (2). A spiral body (5) which is fixed on the inlet (21) side of the rotating shaft (4) and is configured to be expandable and contractible on the rotating shaft (4) and capable of delivering the raw material to the outlet (22) along with the rotation. There is provided a raw material feeding device (1) 'comprising a driving means (6) for driving the rotating shaft (4).

The raw material feeding device (1) of the present invention is intended for solid raw materials such as granules and powders. The inner wall surface of the cylindrical body (2) used in the raw material feeding device (1) is preferably a cylindrical surface, but is not limited thereto.

The outlet (22) provided in the cylinder (2) is
A shape that can be connected to a raw material charging port of an extruder known in the art is preferable. A raw material supply hopper (3) is attached to the inlet (21) of the cylindrical body (2). Inlet (21) and outlet
The (22) is preferably provided on the side peripheral surface of the tubular body (2), but is not limited to this. As the raw material supply hopper (3) attached to the inflow port (21), those known in the art can be used as they are. The raw material supply hopper (3) is preferably provided with a load cell (31).

A solid rotating shaft (4) and a spiral body (5) are provided in the cylindrical body (2) of the raw material feeding device (1). Above rotary shaft
The (4) is arranged in the tubular body (2) along the tubular axis from the inflow port (21) to the outflow port (22). The spiral body (5) is spirally wound along the rotation shaft (4), and is configured to be expandable and contractable along this shaft and the wound state is such that the raw material is a screw-like shaft. It is preferably configured in such a way that it can be delivered in any direction. Also, the above spiral
One end of (5) is fixed on the inlet (21) side of the rotating shaft (4), and the other end is free. This causes the spiral (5) to rotate
It will be able to expand and contract along (4). As the expandable and contractible spiral body (5), as described in "Claim 3" of the present application, a spiral coil (5) can be preferably used. Further, the spiral body (5) is
The size is preferably such that, in the state where it is attached around the rotary shaft (4) and is housed in the cylinder, a gap is formed between it and the peripheral wall surface of the cylinder so that the raw material can flow therethrough.

The driving means (6) is preferably one that can control the rotating shaft (4) so that it can rotate at a predetermined speed, and those known in the art can be used as they are.

The present invention also relates to a raw material feeding device having another structure, that is, as shown in "Claim 2" of the present application, a cylinder having "an inlet (21) at one end and an outlet (22) at the other end. (2), a raw material supply hopper (3) connected to the inflow port (21), and spirally around the cylinder axis from the inflow port (21) to the outflow port (22) in the cylindrical body (2). It is arranged and configured to be hollow along the cylinder axis,
Raw material characterized by comprising a spiral body (8) capable of delivering the raw material to the outlet (22) by being rotated around the cylinder axis, and a drive means (6) for driving the spiral body (8). A feeder (10) 'can be provided.

In the raw material feeding device (10), the cylindrical body
(2) The raw material supply hopper (3) and the driving means (6) may be the same as those used for the raw material feeding device (1).

Helical body used in the raw material feeding device (10)
(8) is spirally wound along the inner peripheral wall surface of the cylindrical body and has a hollow inside, and the wound state delivers the raw material in the axial direction as if it were a screw. It is preferable that it is formed into a flexible shape. Also this spiral
(8) may be provided with a gap from the inner peripheral wall surface, or may be in a state in which there is almost no gap and it can slide on the inner peripheral wall surface.

The spiral body (8) may be a rigid body that does not expand or contract, or an elastic body that can expand or contract. In the case of an elastic body, as shown in “Claim 3” of the present application, a spring coil is preferable.

In the present invention, the above-mentioned raw material feeding device
Both (1) and (10) are preferably used in an extruder. Therefore, the present invention further provides, as shown in "Claim 4" of the present application,
`` Extrusion cylinder (12a) having a raw material inlet (12d) and heating means,
An extrusion screw (12b) that rotates in the extrusion cylinder (12a) to deliver the raw material, and a screw drive unit (12c) that rotationally drives the extrusion screw (12b). mouth
It is possible to provide an extruder (11) 'in which the material outlets (1) and (10) outlets (22) are connected to (12d).

Extrusion cylinder used in the extruder (11) of the present invention
For (12a), the extrusion screw (12b), and the screw driving part (12c), those known in the art can be used as they are.

In the extruder (11), a raw material feeding device
(1) and (10) are preferably attached such that each tubular body (2) is parallel to the extruding barrel (12a).

[0019]

According to the invention of "Claim 1" of the present application, the granular (powder) raw material (7) supplied from the raw material supply hopper (3)
Is introduced into the tubular body (2) through the inlet (21), and in this tubular body (2), the spiral body (5) provided from the inlet (21) to the outlet (22) is rotated. Since the raw material (7) is being rotated along with the rotation of (4), the inflowing raw material (7) is delivered toward the outlet (22) by this spiral body (5). When the outlet (22) is closed, the raw material (7) is stored near the outlet. Then, the raw material (7) delivered in sequence is stored and fills the space at the tip of the cylinder, and accordingly the spiral body
As for (5), the end on the outlet side is free, so
It is pressed by the raw material (7) to be filled and begins to expand and contract along the rotating shaft (4) toward the inflow port (21). The spiral body (5) rotates while expanding and contracting and continues to deliver the raw material (7) to the outlet (22) side. The spiral body (5) continues to rotate like an idle while the (7) is filled in the tubular body (2), whereby the raw material (7) is pressed to the outflow port (22) by an appropriate pressing force. Will continue.

According to the invention of "Claim 2" of the present application,
Raw material such as granules and powder supplied from the raw material supply hopper (3)
The (7) flows into the tubular body (2) through the inflow port (21), but falls and accumulates on the tubular body wall through the gap between the spiral bodies (8) rotating in the tubular body (2). The raw material (7) collected here is discharged from the outlet (22) along the wall surface of the cylindrical body by the rotating spiral body (8).
Will be sent to. When the outlet (22) is closed, the rotating spiral body (8) is hollow here, so the raw material (7) is partially sent to the vicinity of the outlet (22) and partly The hollow portion (81) of the spiral body (8) is filled. Eventually the spiral body (8) even when the raw material (7) is filled in the cylindrical body (2)
Can continue to rotate, whereby the filled raw material (7) can be stirred while being appropriately pressed.

According to the invention of "Claim 3" of the present application,
Since the spiral body (8) is composed of the spring coil, it has elasticity and can appropriately press the raw material.

The raw material feeding devices (1) and (10) are connected to the raw material inlet (12d), and the raw material is always supplied to the extrusion cylinder (12a) with an appropriate pressing force. The raw material (7) is supplied into the extrusion cylinder (12a) in the intended amount regardless of the peaks and valleys of the extrusion screw (12b) rotating in the inside of 12a).

[0023]

The present invention will be described in detail below with reference to the illustrated embodiments, but the present invention is not limited thereto. Embodiment 1 FIG. 1 is a schematic cross-sectional view of an essential part of an example of a raw material feeding apparatus of the invention according to the "claim 1" of the present application. This material feeder (1)
Is a cylinder (2) having an inlet (21) at one end and an outlet (22) at the other end, a raw material supply hopper (3) connected to the inlet (21), and the cylinder (2) a solid rotary shaft (4) arranged along the cylinder axis from the inlet to the outlet, a spiral body (5) provided on the rotary shaft (4), and the rotary shaft (4 ) And a motor (6) for driving the motor.

The inflow port (21) and the outflow port (22) are cylindrical bodies (2).
The outlet (22) is provided on the side peripheral surface of, and can be connected to the raw material inlet of an ordinary extruder.

The raw material supply hopper (3) is commonly used in this field and has a load cell (31) attached thereto.

The rotating shaft (4) is arranged on the central axis of the cylindrical body (2),
The tip is rotatably supported on the front wall of the cylindrical body (2),
The rear end is rotatably supported at the center of the rear wall of the cylinder, and the cylinder (2)
Mounted on the rotating shaft of the motor (6) outside the.

The spiral body (5) has a rotating shaft (4) as shown in the figure.
It is a spring coil-shaped object made of a flat metal wire that is spirally wound around its periphery. One end (inlet side) is embedded and fixed in the rotary shaft, and the other parts are free from the rotary shaft. , Can be expanded and contracted along the rotation axis (4) in the direction of the arrow shown in the figure.

In the raw material feeding device (1) having the above structure,
When granular or powdered raw material (7) is fed by the raw material supply hopper (3), the raw material flowed into the cylindrical body (2) through the inlet (21).
(7) is sequentially delivered toward the outflow port (22) by the spiral body (5) rotating together with the rotating shaft (4). When the outlet (22) is closed, the raw material (7) is stored near the outlet. Then, the raw material (7) that is sequentially sent out is stored and fills the space at the tip of the cylindrical body (2), and accordingly, the spiral body (5) has a free end on the outlet side.
It is pressed by the raw material to be stored and filled, and begins to expand and contract along the axis of rotation toward the inlet side. The spiral body (5) rotates while expanding and contracting and continues to deliver the raw material to the outlet side. However, as shown in FIG. 2, when the spiral body (5) expands and contracts to a certain extent, the expansion and contraction of the spiral body (5) becomes a limit, and here, a certain volume While the raw material (7) is filled in the cylindrical body (2), the spiral body (5) continues to rotate like an idle, whereby the raw material (7) is pressed against the outlet (22) with an appropriate pressing force. Will be continued.

Embodiment 2 FIG. 3 is a schematic cross-sectional view of an essential part of an example of a raw material feeding apparatus according to the present invention "claim 2". This Raw Material Feeder (10)
As for the cylindrical body (2), the raw material supply hopper (3) and the motor (6), the same ones as those in the first embodiment are used, and the description thereof will be omitted. A spiral body (8) is inserted in the cylindrical body (2), and one end of the spiral body (8) is connected to the rotation shaft of the motor (6). The spiral body (8) is composed of a spring coil-shaped object made of a flat metal wire, the coil outer shape of the spiral body (8) is substantially equal to the inner diameter of the cylindrical body (2), and the inside of the spiral body (8) is hollow ( 81).

In the raw material feeding device (10) having the above structure,
When granular or powdered raw material (7) is fed by the raw material supply hopper (3), the raw material flowed into the cylindrical body (2) through the inlet (21).
(7) falls and collects on the cylindrical wall through the gap between the rotating spiral bodies (8). The raw material (7) collected here is delivered toward the outlet (22) along the wall surface of the cylindrical body by the rotating spiral body (8). In this way, when the raw material (7) collects at the tip of the cylinder, if the outlet (22) is blocked,
The accumulated raw material (7) is filled in the hollow portion (81) of the spiral body (8). If this is continued, the raw material (7) will eventually fill the entire space inside the tubular body (2) as shown in FIG. 4, and the spiral body (8) will rotate in the filled raw material (7). Will continue to do. At this time, the propulsive force of the rotating spiral body (8) presses the raw material (7) in the delivery direction and agitates according to this rotation. In the above example,
Although the spiral body (8) that hardly expands and contracts is used, it may be expandable and contractible as in the first embodiment.

Embodiment 3 FIG. 5 is a schematic cross-sectional view of an essential part of an example of an extruder according to the present invention "claim 4". In the figure, the extruder (11)
Is a known extruding cylinder (12a) equipped with a heating means (not shown), a known extruding screw (12b), and a known screw drive, for the outlet (22) of the raw material feeding device (1) of Example 1. It is connected to the raw material inlet (12d) of the extrusion means (12) provided with the section (12c). The die part of the extruding means (12) is omitted.

In this extruder (11), the raw material feeding device
Since (1) continuously presses the raw material with an appropriate pressure as described above and continuously stirring it, any of the peaks and valleys of the extrusion screw (12b) in the raw material input port (12d) of the extrusion cylinder (12a). Even if is located, the raw material is smoothly supplied, and the decreasing flow of the raw material in the raw material supply hopper (3) is smooth. Therefore, when the amount of raw material flowing into the extruder is measured by the weight change per unit time by the load cell (31) attached to the raw material supply hopper (3), no matter how small the amount of extrusion (in other words, Then, no matter how low the screw rotation speed is), an accurate amount of raw material can be supplied to the extruder (11). Therefore, even when a color is added to the molding raw material, a small amount of color can be accurately supplied, and color unevenness does not occur in the finished product.

Embodiment 4 FIG. 6 is a schematic cross-sectional view of essential parts of another example of the extruder according to the present invention "claim 4". In the figure, the extruder (13)
Is a known extruding cylinder (12a), an extruding screw (12b), and a screw driving unit, which are connected to the outlet (22) of the raw material feeding device (10) of the second embodiment.
It is connected to the raw material inlet (12d) of the extrusion means (12) equipped with (12c). The die part of the extruding means (12) is omitted.

Also in this extruder (13), the raw material feeding device
Since (10) continuously presses the raw material with an appropriate pressure as described above and continuously stirring it, any of the peaks and valleys of the extrusion screw (12b) in the raw material charging port (12d) of the extrusion cylinder (12a). Even if is located, the raw material is smoothly supplied, and the decreasing flow of the raw material in the raw material supply hopper (3) is smooth. Therefore, when the amount of raw material flowing into the extruder is measured by the weight change per unit time by the load cell (31) attached to the raw material supply hopper (3), no matter how small the amount of extrusion (in other words, Then, no matter how low the screw rotation speed is), an accurate amount of raw material can be supplied to the extruder (13). Therefore, even when a color is added to the molding raw material, a small amount of color can be accurately supplied, and color unevenness does not occur in the finished product.

[0035]

According to the raw material feeding device of the present invention, the raw material can be supplied while being constantly pressed with an appropriate pressure and agitated, so that the manner of decrease accompanying the raw material supply in the raw material supply hopper becomes smooth. The amount of weight loss per unit time can be accurately detected. Since the extruder of the present invention is provided with the above-mentioned raw material feeding device, even a very small amount of raw material can be accurately fed into the extruder, and the feed ratio of the raw material to the extrusion amount can be accurately controlled.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a main part of an example of a raw material feeding device according to “Claim 1” of the present application.

FIG. 2 is a schematic cross-sectional view of a main part for explaining a raw material feeding state in the raw material feeding device of FIG.

FIG. 3 is a schematic cross-sectional view of an essential part of an example of a raw material feeding device according to the “claim 2” of the present application.

4 is a schematic cross-sectional view of a main part for explaining a raw material feeding state in the raw material feeding device of FIG.

5 is a schematic cross-sectional view of an essential part of an extruder equipped with the raw material feeding device of FIG.

6 is a schematic cross-sectional view of an essential part of an extruder equipped with the raw material feeding device of FIG.

[Explanation of symbols]

(1), (10) ... Raw material feeding device (2) ... Cylindrical body (3) ... Raw material supply hopper (4) ... Rotating shafts (5), (8) ... Helical body (7) ... Raw material (6) ... Motor ( 11), (13) ...
Extruder (12) ... Extrusion means (12a) ... Extrusion cylinder (12b) ... Extrusion screw (12c) ... Screw drive part (12d) ... Raw material input port (21) ... Inflow port (22) ... Outflow port

Claims (4)

[Claims] 1. A cylinder having an inflow port at one end and an outflow port at the other end, a raw material supply hopper connected to the inflow port, and an inflow port to an outflow port along a cylinder axis in the cylinder. A solid rotary shaft arranged up to, a spiral body fixed on the inlet side of the rotary shaft so as to be expandable and contractible on the rotary shaft, and capable of delivering the raw material to the outlet with rotation, and the rotary shaft. A raw material feeding device comprising a driving means for driving. 2. A cylinder having an inlet at one end and an outlet at the other end, a raw material supply hopper connected to the inlet, and a spiral around the cylinder axis from the inlet to the outlet in the cylinder. Are arranged in a hollow shape and are hollow along the cylinder axis,
A raw material feeding device comprising a spiral body capable of sending a raw material to an outlet by being rotated around a cylinder axis, and a drive means for driving the spiral body. 3. The raw material feeding apparatus according to claim 1, wherein the spiral body is a spring coil. 4. An extruding cylinder having a raw material charging port and a heating means, an extruding screw for rotating the extruding cylinder to deliver the raw material, and a screw driving section for rotationally driving the extruding screw. An extruder in which the outlet of the raw material feeding device according to any one of claims 1 to 3 is connected to the inlet.