JP2006231767A - Extrusion molding apparatus and molding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an extrusion molding apparatus and a molding method in which the fluctuation in cut length of a molded body becomes small and which can obtain a molded article of high dimensional accuracy. <P>SOLUTION: The extrusion molding apparatus comprises: a die 1 having an extrusion opening 3 with which a molded article 11 is extruded continuously; a cutting-off unit 2 for cutting a molded article 11 extruded from the extrusion opening 3; a screw conveyor 17 which is prepared inward of the extrusion opening 3 and controls an extruding rate of a molded body 11 extruded from the extrusion opening 3; a sensor 12 for detecting the extruding speed of a molded article 11 extruded from the extrusion opening 3; and a control means 40 for controlling the rotational speed of the screw conveyor 17 based on an incoming signal from this sensor 12. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an extrusion molding apparatus capable of minimizing variation in the cutting length of a molded body and a molding method using the same.

  In general, a catalyst, a catalyst carrier, an adsorbent, a desiccant, a humidity control material, etc. are formed into a columnar or cylindrical shape having a diameter of about 1 to 10 mm and a length of about 2 to 20 mm. Used in chemical reaction processes. In order to produce such a molded article such as a catalyst, an extrusion molding method has been conventionally employed. That is, a compact is produced by cutting a compact obtained by continuously extruding a soft clay-like material such as alumina from a die.

  At that time, if the molded body is cut with a blade or the like, the cut end portion of the molded body is deformed and cannot be densely filled in the reactor. The problem of disturbing the process arises.

  Therefore, in Patent Document 1, a soft molded body immediately after being extruded from a die is cut with a piano wire stretched between two points. That is, using a support plate with a piano wire stretched between two points, this support plate is rotated or reciprocated in a direction perpendicular to the extrusion direction, and the piano wire is moved over the front surface of the extrusion hole at regular intervals. The formed body immediately after extrusion is cut by traversing.

  In this case, if the cutting speed of the piano wire is set to a constant value and the molded body is cut, the cutting speed of the molded body changes when the extrusion speed of the molded body changes even slightly due to changes in the viscosity of the molding material. As described above, there is a problem that a large variation occurs in the length, and the molded product cannot be densely filled in the reactor as described above. Therefore, in Patent Document 1, the extrusion speed of the molded body is detected by a sensor, and the speed at which the cutting device rotates or reciprocates is controlled.

  Further, in Patent Document 2, when the extrusion speed of the molded body changes, the opening / closing operation of a flow control valve provided inside the extrusion hole is controlled based on the input signal from the sensor to push the molded body. It is described that the speed is adjusted, thereby adjusting the cut length of the shaped body. Further, Patent Document 2 describes that it is preferable to control the cutting device as well as the flow control valve in order to reduce the variation in the cutting length of the molded body.

JP 2002-67020 A JP 2002-79568 A

As described in Patent Document 2, the method of controlling the flow rate by opening and closing the flow rate control valve has a problem that the response from the start of control until the extrusion flow rate changes is slow. For this reason, even if the control of the flow control valve and the control of the cutting device are combined, it is difficult to reduce the variation in the cutting length of the molded body.
Accordingly, an object of the present invention is to provide an extrusion molding apparatus capable of reducing variation in the cut length of a molded body and obtaining a molded product with high dimensional accuracy, and a molding method using the same.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have provided a screw conveyor inside the extrusion hole, and in response to a change in the rotational speed of the screw conveyor, the molded body extruded from the extrusion hole. The amount of extrusion follows closely, that is, it has excellent responsiveness, which makes it easy to control the flow rate at which the molded body is extruded, and finds the new fact that variation in the cutting length of the molded body can be reduced. The invention has been completed.

That is, the extrusion molding apparatus of the present invention has the following configuration.
(1) A die having a plurality of extrusion holes for continuously extruding the molded body, a cutting device for cutting the molded body extruded from the extrusion holes, and a molded body provided inside the extrusion holes and extruded from the extrusion holes A screw conveyor for controlling the extrusion speed of the machine, a sensor for detecting the extrusion speed of the molded body extruded from the extrusion hole, and a control for controlling the number of revolutions of the screw conveyor based on an input signal from the sensor And an extrusion molding apparatus.
(2) The control means controls the rotational speed of the screw conveyor for each extrusion hole so that the cutting length of each molded body extruded from the plurality of extrusion holes approaches the average value of the cutting lengths of the molded body. The extrusion molding apparatus according to (1), wherein the extrusion speed of the molded body is adjusted.
(3) The control means controls the rotation speed of the screw conveyor for each extrusion hole so that the cutting length of each molded body extruded from the plurality of extrusion holes approaches the set value of the cutting length of the molded body. The extrusion molding apparatus according to (1), wherein the extrusion speed of the molded body is adjusted.
(4) The sensor is a spot light source type sensor, and the extrusion speed of the molded body is detected by measuring the time until the molded body reaches the measurement point of the sensor from the extrusion hole (1) to (3 The extrusion molding apparatus according to any one of the above.
(5) A die having a plurality of extrusion holes through which the molded body is continuously extruded and a wire stretched between two points, and rotated or reciprocated in a direction perpendicular to the extrusion direction of the molded body. , A cutting device for cutting the wire rod across the front surface of the extrusion hole and cutting the molded body immediately after extrusion, and a screw conveyor for controlling the extrusion speed of the molded body provided inside the extrusion hole and extruded from the extrusion hole A sensor for detecting the extrusion speed of the molded body extruded from the extrusion hole, a speed control for rotating or reciprocating the cutting device based on an input signal from the sensor, and a control for the rotational speed of the screw conveyor And an extrusion molding apparatus.
(6) The control means rotates or reciprocates the cutting device so that the average value of the cutting length of each molded body extruded from the plurality of extrusion holes approaches the set value of the cutting length of the molded body. And controlling the number of rotations of the screw conveyor for each extrusion hole so that the cutting length of each molded body extruded from each extrusion hole approaches the average value of the cutting lengths of the molded body. The extrusion molding apparatus according to claim 5, wherein the extrusion speed is adjusted.

Moreover, the shaping | molding method concerning this invention consists of the following structures.
(7) While continuously extruding the molded body from a plurality of extrusion holes provided in the die, the extrusion speed of the molded body extruded from the extrusion hole is detected by a sensor, and based on the input signal from the sensor, the extrusion A molding method characterized by controlling the number of revolutions of a screw conveyor provided inside the hole to adjust the extrusion speed of the molded body, and sequentially cutting the molded body into a predetermined length by a cutting device.
(8) While continuously extruding the molded body from a plurality of extrusion holes provided in the die, the extrusion speed of the molded body extruded from the extrusion hole is detected by a sensor, and based on the input signal from the sensor, the extrusion From the extrusion hole, the speed of the wire rod stretched between two points traversing the front surface of the hole is controlled to rotate or reciprocate, and the number of rotations of the screw conveyor provided inside the extrusion hole is controlled. A molding method characterized by adjusting the extrusion speed of the extruded molded body and sequentially cutting the molded body immediately after extrusion into a predetermined length.

  According to the present invention, since the extrusion flow rate of the molded body closely follows the rotational speed of the screw conveyor provided inside the extrusion hole, even if the extrusion speed of the molded body changes due to a change in the viscosity of the molding material, etc. The extrusion amount of the molded body can be controlled to an appropriate value, and the response is excellent. Therefore, the variation in the cutting length of the molded body is reduced, and the dimensional accuracy is improved. In particular, when the die has a plurality of extrusion holes and a molded body is extruded from each extrusion hole, the flow rate can be controlled quickly for each extrusion hole.

One embodiment of the present invention is shown in FIGS. FIG. 1 shows an outline of an extrusion molding apparatus according to this embodiment, and a cutting device 2 is provided on the front surface of a die 1.

  The die 1 is attached to the front surface of the extrusion apparatus 10 and has a plurality of extrusion holes 3 through which the molded body is continuously extruded. Further, the cutting device 2 has a piano wire 6 (wire material) stretched between two guides 4 and 5. The piano wire 6 moves along the front surface of the extrusion hole 3 while contacting the top surface of the bulging portion 15 provided with the extrusion hole 3, and cuts the molded body 11 extruded from the die 1 by a predetermined length. The molded product 7 is obtained.

  In other words, the cutting device 2 includes a disk-shaped mounting plate 9 that is integrally mounted perpendicularly to the rotating shaft 8 on a rotating shaft 8 that is arranged in parallel with the extrusion direction. The rotating shaft 8 is rotated by a rotation drive unit 16 (motor) to rotate in a direction orthogonal to the extrusion direction of the molded body 11.

  The rotating shaft 8 is provided coaxially with the central axis of the disk-shaped die 1. As shown in FIG. 2, since the plurality of extrusion holes 3 are concentrically arranged in the die 1, the rotating shaft 8 is rotated and the mounting plate 9 is rotated, so that it is stretched on the front surface thereof. The piano wire 6 that has passed passes through the front surface of each extrusion hole 3. As shown in FIG. 2, two piano wires 6 and 6 are stretched on the mounting plate 9 in opposite directions to each other via the rotation shaft 8. Cutting is done. The diameter of the piano wire 6 to be used may be determined in consideration of the material of the molded body, the diameter, etc., but usually 300 μm or less is appropriate.

  On the other hand, screw conveyors 17 are provided inside the respective extrusion holes 3. The screw conveyor 17 has a blade 17b attached to the tip of a rotating shaft 17a. The rotary shaft 17 a is attached with a driven gear 30 that is pulled out of the extrusion device 10, and a driven gear 32 that is driven to rotate by a motor 31 meshes with the driven gear 30 to rotate the screw conveyor 17. The number of blades 17b of the screw conveyor 17 is not particularly limited and may be about 1 to 4, but the number of blades 17b is 1 (that is, 1 pitch) as shown in FIG. It is preferable for uniformly extruding the molded product in the chamber 33 facing the extrusion hole 3. The shape of the blade 17b is not particularly limited.

  A spot light source type sensor 12 is provided at a position separated from the front surface of the extrusion hole 3. Examples of the sensor 12 include a sensor that is used for the purpose of distance measurement, for example, using a laser beam or a light emitting diode as a light source. In particular, an irradiation unit that irradiates an object with spot light and light reflected from the object. It is preferable to use a reflection type sensor (for example, a reflection type laser sensor) provided with a light receiving unit that receives the light in order to make the entire apparatus compact.

  The mounting position of the sensor 12 is a part where the spot light can be irradiated to the path through which the molded body 11 extruded from the die 1 passes on the side away from the die 1. Using this sensor 12, the time until the molded body 11 reaches the measurement point of the sensor 12 from the extrusion hole 3 is measured. That is, immediately after the first cutting, since the molded body 11 does not exist at the measurement point (that is, the light irradiation point) of the sensor 12, the sensor 12 does not detect the molded body 11, but after the first cutting, it is newly pushed out. When the tip of the molded body 11 reaches the measurement point, the sensor 12 detects the molded body 11, and therefore the time t1 from the first detection to the second detection is known. Since the distance L from the extrusion hole 3 to the measurement point of the sensor 12 is set in advance, the extrusion speed V of the molded body 11 is obtained from the formula: L / t1. Note that the distance L from the extrusion hole 3 to the measurement point of the sensor 12 is equal to or smaller than the cutting length from the extrusion hole 3.

  On the other hand, the time t2 from when the piano wire 6 passes the front surface of the extrusion hole 3 for the first time to the second time by measuring the rotational speed of the cutting device 2 is obtained from the calculation, so the formula: V × The cutting length X of the molded body 11 is detected from t2.

  The sensor 12 is installed about all the extrusion holes 3 as shown in FIG. That is, the sensor 12 is installed in each of the eight extrusion holes 3 arranged concentrically on the disk-shaped die 1.

  FIG. 3 also shows details of the control mechanism in this embodiment. An input signal from each sensor 12 is sent to the input unit 19 in the control means 40 (sequencer) through the input switching device 18. On the other hand, the rotational speed (or rotational speed) of the rotary shaft 8 of the cutting device 2 is detected by the rotary encoder 20 and sent to the CPU 21 (central processing unit).

In the CPU 21, as shown in FIG. 4, the cutting length Xn is obtained from the extrusion speed of the molded body 11 in each extrusion hole 3 detected by the sensor 12 disposed in each extrusion hole 3, and the cutting length is determined from this. An average value Xav is calculated.
Then, the cutting length Xn at each extrusion hole 3 is compared with the average value Xav of the cutting length, and when Xn> Xav, the rotational speed (or rotational speed) of the screw conveyor 17 is reduced to suppress the flow rate. Then, the extrusion speed is decreased and controlled so that X = Xav. Conversely, when X <Xav, the rotational speed of the screw conveyor 17 is increased to increase the flow rate, the extrusion speed is increased, and control is performed so that X = Xav. In the case of X = Xav, the rotational speed of the screw conveyor 17 remains unchanged.

  These control signals are sent from the D / A conversion unit 22 through the inverter 23 to the respective rotary drive units 31a, 31b, 31c,... 31h provided in the screw conveyors 17 for each extrusion hole 3. Flow rate control (and hence extrusion speed control) is performed. For this reason, the variation in the extrusion speed between the respective extrusion holes 3 is reduced, and the variation in the cutting length Xn around the average value Xav can be made extremely small. The cutting length Xn may be compared with the set value X0 of the cutting length instead of the average value Xav of the flat cutting length, thereby improving the dimensional accuracy of each cutting length Xn.

  Further, in the cutting device 2, the average value Xav and the initial set value X0 of the cutting length are compared, and when Xav> X0, the rotational speed of the rotation drive unit 16 is reduced, and conversely, Xav <X0. In some cases, the number of rotations of the rotation drive unit 16 is increased, and X = X0 is controlled. When X = X0, the rotation speed of the rotation drive unit 16 is unchanged.

  The output signal to the rotation drive unit 16 is sent from the D / A conversion unit 22 to the rotation drive unit 16 via the inverter 23, and the rotation speed (and hence the rotation speed) is adjusted. As a result, the cutting length can be made closer to the set value X0, and the dimensional accuracy of the molded product 7 obtained by cutting the molded body 11 is improved.

  On the other hand, data is recorded from the output unit 24 to the recorder 26 via the D / A converter 25. Further, the cutting length data can be sent from the personal computer link unit 27 to the length indicator 28 and displayed.

  Next, the die 1 used in this embodiment will be described. The inner diameter of the extrusion hole 3 in the die 1 is about 1 mm to 10 mm, preferably about 3 mm to 6 mm. The number of extrusion holes may be determined in consideration of the outer diameter of the die, the inner diameter of the extrusion hole, and the like. For example, 1, 2, 4, 8, 16, 32, 64, 128, 256, 400 etc. are mentioned. The shape of the extrusion hole may be, for example, a ring, a honeycomb, or a clover shape in addition to a circle.

Specific examples of the molded product include, for example, a catalyst, a catalyst carrier, an adsorbing material, a drying material, and a humidity control material. Further, the material of the molded body is not limited to the inorganic material, and the extrusion molding apparatus of the present invention can be applied to various plastic materials and the like. In that case, the wire to be used is not limited to the piano wire, but may be another metal wire or a wire made of a plastic material, a fiber material, or the like. Further, in the above embodiment, the mounting plate 9 is configured to rotate. However, the mounting plate 9 may be reciprocated in a direction orthogonal to the extrusion direction of the molded body. In this case, the reciprocating speed is controlled. That's fine.
Hereinafter, the extrusion molding apparatus of the present invention will be described with reference to Examples and Comparative Examples.

  A clay-like alumina catalyst molded body was extruded using the extrusion molding apparatus shown in FIGS. The die 1 used has a surface plated with chromium and has a disk shape in which eight extrusion holes 3 are arranged concentrically. The extrusion hole 3 has an inner diameter of 5 mm. The cutting device 2 was rotated at about 90 times / second while bringing the piano wire 6 having a diameter of 150 μm into contact with the top surface of the bulging portion 15 provided with the extrusion hole 3. Using the die 1 and the cutting device 2, the alumina catalyst molded body was extruded at an extrusion speed of about 1300 mm / min. As a result, the cut length of the molded body 11 was an average of 6.3 mm, and the standard deviation was 0.44 mm.

[Comparative example]
Except that the control using the sensor 12 was not performed, the alumina catalyst molded body was extruded in the same manner as in Example 1. As a result, the cut length of the molded body 11 was an average of 6.3 mm, and the standard deviation was 1.08 mm.
As mentioned above, it turns out that the molded object obtained in the Example has small dispersion | variation in the cutting length compared with a comparative example.

It is a schematic sectional drawing which shows the extrusion molding apparatus which is one Embodiment of this invention. It is a schematic explanatory drawing which shows the relationship between the wire for cutting | disconnection, and the extrusion hole of die | dye. It is a schematic explanatory drawing which shows the control mechanism of an extrusion molding apparatus. It is a block diagram which shows a control mechanism.

Explanation of symbols

1 Die 2 Cutting device 3 Extrusion hole 6 Piano wire (wire)
7 Molded product 8 Rotating shaft 11 Molded body 12 Sensor 16 Screw conveyor 40 Control means

Claims (8)

  A die having a plurality of extrusion holes for continuously extruding the molded body, a cutting device for cutting the molded body extruded from the extrusion holes, and an extrusion speed of the molded body provided inside the extrusion holes and extruded from the extrusion holes A screw conveyor for controlling the pressure, a sensor for detecting the extrusion speed of the molded body extruded from the extrusion hole, and a control means for controlling the rotational speed of the screw conveyor based on an input signal from the sensor. An extrusion apparatus characterized by comprising.   The control means controls the number of rotations of the screw conveyor for each extrusion hole so that the cutting length of each molded body extruded from the plurality of extrusion holes approaches the average value of the cutting lengths of the molded body. The extrusion apparatus according to claim 1, wherein the extrusion speed of the body is adjusted.   The control means controls the number of rotations of the screw conveyor for each extrusion hole so that the cutting length of each molded body extruded from the plurality of extrusion holes approaches the set value of the cutting length of the molded body. The extrusion apparatus according to claim 1, wherein the extrusion speed of the body is adjusted.   The said sensor is a spot light source type sensor, The extrusion speed of a molded object is detected by measuring the time until a molded object reaches | attains the measurement point of this sensor from an extrusion hole. The extrusion molding apparatus as described.   The wire has a die having a plurality of extrusion holes through which the formed body is continuously extruded, and a wire stretched between two points, and rotates or reciprocates in a direction perpendicular to the extrusion direction of the formed body. A cutting device for cutting the molded body immediately after extrusion, the screw conveyor for controlling the extrusion speed of the molded body provided inside the extrusion hole and extruded from the extrusion hole, A sensor for detecting the extrusion speed of the molded body extruded from the extrusion hole, a speed control for rotating or reciprocating the cutting device based on an input signal from the sensor, and a control for the rotation speed of the screw conveyor. And an extrusion molding apparatus.   The control means controls the speed at which the cutting device rotates or reciprocates so that the average value of the cutting length of each molded body extruded from the plurality of extrusion holes approaches the set value of the cutting length of the molded body. In addition, the rotational speed of the screw conveyor is controlled for each extrusion hole so that the cutting length of each molded body extruded from each extrusion hole approaches the average value of the cutting lengths of the molded body, thereby increasing the extrusion speed of the molded body. The extrusion molding apparatus according to claim 5 to be adjusted.   While continuously extruding the molded body from the plurality of extrusion holes provided in the die, the sensor detects the extrusion speed of the molded body extruded from the extrusion hole, and based on the input signal from the sensor, A molding method comprising controlling the number of revolutions of a screw conveyor provided on the side to adjust the extrusion speed of the molded body, and sequentially cutting the molded body into a predetermined length by a cutting device. While the molded body is continuously extruded from a plurality of extrusion holes provided in the die, the extrusion speed of the molded body extruded from the extrusion hole is detected by a sensor, and the front surface of the extrusion hole is detected based on an input signal from the sensor. A molding that is extruded from the extrusion hole by controlling the speed of rotation or reciprocation of the wire stretched between two points crossing the wire and controlling the number of revolutions of the screw conveyor provided inside the extrusion hole. A molding method comprising adjusting the extrusion speed of a body and sequentially cutting the molded body immediately after extrusion into a predetermined length.

Images