JPH0985809A - Apparatus for detecting metal piece in resin material and injection molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect the metal piece mixed with a fed resin material and to achieve the information and exclusion of the mixing of the metal piece. SOLUTION: A spiral shaft 3 formed from a non-magnetic material is arranged in a cylinder 2 having a material supply part at one end thereof, a material discharge part at the other end thereof and the detection part 7 formed between the supply part 6 and the discharge part 8 using a non-magnetic material in a rotatable manner and a rotary drive device 5 is connected to the spiral shaft 3 and a metal sensor 4 is arranged to the outer periphery of the detection part 7. At least one permanent magnets 32a, 32b can be embedded in the shaft part between the spiral blades 31 in the spiral shaft 3 on the side of the discharge part 8 separated from the detection part 7 or on the side of the supply part 6. An alarm 41 and a rotary drive device 5 are electrically connected to a sensor 4 and the alarm 41 is operated by the metal piece detection signal from the sensor 4 and the rotation of the spiral shaft 3 is stopped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to supplying a granular resin material from a material hopper to a heating cylinder of a resin molding machine such as an injection molding machine or an extrusion molding machine, or transporting the material to a predetermined place. The present invention relates to a metal piece detection device in a resin material for detecting metal pieces mixed in a feed passage, and an injection molding machine equipped with the metal piece detection device.

[0002]

2. Description of the Related Art In plastic molding, if a metal piece is mixed with a molding material while molding, the metal piece is clogged with a nozzle of a molding machine and cannot be molded, or the metal piece passes through the nozzle and is embedded in a molded product. The problem arises. Especially,
In the injection molding of industrial plastics, the hardness of the industrial plastics is high, so that the crusher is likely to have a blade spill. If the metal piece is molded while being mixed with the resin material, the metal piece is caught in the check valve of the molten resin provided at the tip of the heating cylinder of the injection molding machine, and molding cannot be performed. In this case, wait for the resin in the heating cylinder to cool before removing the check valve from the heating cylinder to remove the clogged metal pieces. It was significantly reduced.

In order to prevent the metal pieces from being mixed, a device using a metal sensor (4) is known as follows. As shown in FIG. 4, this is the material hopper vertically above the material supply side of the heating cylinder (92) in the molding machine.
(90) is provided, and the material hopper (90) and the heating cylinder (92) are connected to each other through the transfer pipe (91). A metal sensor (4) is provided around the transport pipe (91), and below the sensor (4),
A metal discharge mechanism (93) such as an opening / closing device and a suction pump is provided. The sensor (4) and the discharge mechanism (93) are electrically connected via the amplifier (40) and the controller (42). The metal sensor (4) uses a coil to generate an oscillating magnetic field or a stationary magnetic field in the carrier pipe (91), and the coil or another coil is used to electrically generate an oscillating magnetic field or a stationary coil by changing the impedance of the coil or the induced voltage. Detect changes. Transport Pipe (91)
When the metal piece passes through the inside, the sensor (4) emits a detection signal. The amplifier (40) amplifies the detection signal from the sensor (4) and sends it to the controller (42). Controller (4
2) controls the discharge mechanism (93) to transfer the metal pieces to the pipe (9
It is set to discharge from 1).

[0004]

However, in this device, since the falling velocity of the material is accelerated by gravity,
The longer the delay between the detection of the metal sensor (4) and the activation of the metal discharge mechanism (93), the more
It is necessary to lengthen the distance H between (4) and the discharge mechanism (93), and the device becomes large. Moreover, it is difficult and certain to detect and eliminate the metal piece that freely falls in the transfer pipe (91) during a short time when it passes through the sensor (4) and the discharge mechanism (93). The operation was difficult.

The inventor of the present application has previously arranged a spiral shaft made of a non-magnetic material in a feed passage of a granular material, and embedding a magnet in the spiral shaft so that when the spiral shaft feeds the granular material, the magnet We proposed a device that adsorbs metal pieces and prevents them from mixing (Jpn. 4-35142). Although this device is excellent in preventing the mixing of metal pieces, it has the inconvenience of periodically pulling out the spiral shaft from the cylinder and checking it in order to know the presence of metal pieces adsorbed by the magnet. .

[0006]

Means for Solving the Problems To solve the above problems,
The present invention is configured as follows. The cylinder has a material supply unit, a material discharge unit, and a detection unit, and the detection unit is formed of a nonmagnetic material and is arranged between the supply unit and the discharge unit. A spiral shaft formed of a non-magnetic material is rotatably arranged in the cylinder, and a rotary drive device is connected to the spiral shaft. A metal sensor is provided on the outer circumference of the detection portion of the cylinder. The sensor uses a coil to generate an oscillating magnetic field or a stationary magnetic field in the detection unit, and the coil or another coil is used to detect an electrical change of the coil. Further, at least one permanent magnet can be embedded in the shaft portion between the spiral blades in the spiral shaft on the side of the emission unit or the side of the supply unit that is distant from the detection unit. Further, an alarm may be electrically connected to the sensor, and the alarm may be activated when it is detected that the metal piece is mixed in the resin material in the detection unit by the operation of the sensor. The sensor is electrically connected to the rotary drive device,
The rotation of the spiral shaft can be set to stop when the metal piece is detected in the resin material in the detection unit by the operation of the sensor. Further, a switch is provided at the material discharge port of the discharge section, the switch is electrically connected to the sensor, and when the sensor operation detects a mixture of metal pieces in the resin material, the switch is opened and closed. Can be configured to close the material outlet.

[0007]

According to the present invention, the spiral shaft is rotated by the rotary drive device, and the resin material is conveyed by the screw thrust due to the rotation of the spiral shaft. Then, the metal sensor generates an oscillating magnetic field or a stationary magnetic field in the detection unit. At this time,
When a metal piece is mixed in the material, it appears as an electrical change due to the change in the impedance of the coil in the sensor or the induced voltage.By detecting this, the metal piece is mixed in the material in the detection part. That is, the sensor outputs a detection signal. Since the speed of material conveyance by the spiral shaft is determined by the rotational speed of the shaft and the blade angle, a constant speed that is not high can be maintained.
Further, since the material can be densely conveyed by the spiral shaft, the speed can be reduced. Therefore, a reliable operation can be expected in the detection and discharge of the metal piece by the sensor and the elimination device. In order to generate a magnetic field sufficient for the metal sensor to detect a metal piece in the resin material in the detection part, the detection part and the spiral shaft of the cylinder are made of a non-magnetic material such as plastic, ceramics, or glass. To be

Further, by embedding a permanent magnet in the spiral shaft on the side of the material discharge portion which is far from the detection portion, the metal piece detected by the sensor can be surely adsorbed by the magnet, which is smaller than the conventional metal piece detection device. Can be realized. Further, if a permanent magnet is embedded in the spiral shaft on the side of the material supply unit that is remote from the detection unit, the magnet adsorbs the metal piece before the sensor detects the metal piece, so the number of times the sensor detects the metal piece is reduced. It is possible to improve work efficiency. Further, if an alarm is used, a metal piece detection signal from the sensor is transmitted to the alarm, and the alarm notifies that the metal piece is mixed. Therefore, as compared with the conventional method in which the magnet is embedded in the spiral shaft, the mixing of the metal pieces can be confirmed by an alarm, which is convenient. Also,
If the method of stopping the rotary drive is used, the rotary drive receives the metal piece detection signal from the sensor, stops the rotation of the spiral shaft, and interrupts the material conveyance. Therefore, it is possible to reliably prevent the metal piece from being sent to the heating cylinder, and it is possible to realize a smaller size than the conventional metal piece detecting device. further,
If the opening / closing device provided at the material outlet is used, the material outlet is closed by the metal piece detection signal from the sensor,
It is possible to more reliably prevent the metal piece from being sent to the heating cylinder.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described in detail below with reference to the drawings. As shown in FIG. 2, in the injection molding machine, the heating cylinder is provided between the material passages through which the material supplied from the material hopper (90) is sent to the heating cylinder (92).
A device for detecting metal fragments in the resin material of the present invention (1) in parallel with (92)
Is deployed. The cylinder (2) of the device is a material supply unit.
(6), a detection part (7) and a material discharge part (8).

As shown in FIG. 3, the material supply part (6) has a material supply port (60) at the upper part, and the material from the material hopper (90) is passed through the supply port (60) to the cylinder (2). Is supplied in. The material discharge part (8) has a through hole (8
0) is formed, and the through hole (80) communicates with the cylinder (2). The lower opening of the through hole (80) serves as a material discharge port (81) for discharging the material to the heating cylinder (92) through the transfer pipe (91). The upper opening (82) of the through hole (80) is closed by the upper lid (83). The valve body (84) is removably arranged in the material discharge port (81) which is the lower opening of the through hole (80). Disc (84)
The opening / closing operation of is controlled by the controller (42). The detection part (7) is provided between the supply part (6) and the emission part (8) and generates a magnetic field sufficient to detect a metal piece in the feed passage (70) inside thereof. In the detection part (7)
The cylinder wall of is made of non-magnetic material such as plastic, ceramics, glass and the like. Supply unit (6) and discharge unit (8)
Are fixed and supported by the cylinder support base (20) of FIG.

A metal sensor (4) is provided surrounding the detection section (7). The sensor (4) is similar to the sensor described in (Prior Art). The detection signal from the sensor (4) is transformed into an appropriate waveform and amplified by the amplifier (40), and the alarm (4
1) and the controller (42).

A spiral shaft (3) is arranged in the cylinder (2). The spiral shaft (3) has a single spiral blade (3
1) is protruding. The shaft part (30) of the spiral shaft (3) and the spiral blade (31) are made of a non-magnetic material such as plastic, ceramics, glass, etc., similar to the detection part (7). Spiral axis (3)
The permanent magnets (32a) (32b) on the shaft part (30) between the spiral blades (31) on the material supply part (6) side and the material discharge part (8) side from the position of the sensor (4), respectively. Is buried. Material Supply Department (6)
In, the end of the spiral shaft (3) removably penetrates the bearing (62) provided in the base end opening (61) of the cylinder (2), and the joint (50) of the rotary drive unit (5). ) Is integrally rotatable and detachably engaged. The rotation drive of the rotation drive device (5) is controlled by the controller (42). In the material discharge part (8), the end of the spiral shaft (3) is connected to the base end opening (8) of the cylinder (2).
It is rotatably supported by a lid body (86) provided in 5) via a bearing (87). When the lid body (86) is removed and the spiral shaft (3) is pulled out, the engagement between the spiral shaft (3) and the joint (50) of the rotary drive device (5) is released, and the spiral shaft (3) is removed from the cylinder (2). ) Can be taken out.

The alarm (41) is set to give an alarm by light or sound when the detection signal from the amplifier (40) is received. When the controller (42) receives the detection signal from the amplifier (40), it stops the rotation drive of the rotation drive device (5) and, at the same time, advances the valve body (84) to the material discharge port (81) to move the material. It is set to close the outlet (81).

However, the rotary shaft (5) is used to rotate the spiral shaft.
When (3) is rotated, the resin material loaded from the material hopper (90) causes the resin material introduced from the material hopper (90) to be rotated by the screw thrust of the spiral shaft (3) to the cylinder (2).
It is conveyed from the supply part (6) of the material to the discharge part (8) through the detection part (7) and is discharged from the material discharge port (81) to the heating cylinder (92) through the transfer pipe (91). Then, the metal sensor (4) generates an oscillating magnetic field or a stationary magnetic field in the detection section. At this time, if the metal piece is mixed in the resin material,
When the metal piece enters the detection area, the sensor (4) detects the mixing of the metal piece and outputs a detection signal. When the detection signal is amplified by the amplifier (40) and transmitted to the alarm (41) and the controller (42), the alarm (41) gives an alarm by light or sound, and the metal piece is emitted from the sensor (4). Discharge part (8)
It is possible to prevent the metal piece from being adsorbed by the magnet (32b) on the side and mixing into the heating cylinder (92). At this time, the controller (42) stops the rotation drive of the rotation drive device (5), and the valve body
By projecting the (84) to the material discharge port (81) and closing the material discharge port (81), the mixed metal pieces can be reliably confined in the cylinder (2).

After the rotational drive of the rotary drive device (5) is stopped, the lid body (86) is removed and the spiral shaft (3) is pulled out, and the spiral shaft (3) is removed.
Magnets (32a) (32b) embedded in the
(2) It is only necessary to remove the metal pieces confined inside. After removing the metal piece, the spiral shaft (3) is returned into the cylinder (2), the lid (86) is attached, and the valve body (84) is retracted to release the material (81).
Open and release the alarm (41) to turn the rotary drive.
By restarting the rotational drive of (5), the material transport can be restarted. Further, since the metal piece is attracted to the upstream magnet (32a), the number of times the rotary drive device (5) is stopped due to the passage of the metal piece can be reduced, and the work efficiency can be improved.

When the industrial plastic is crushed, the blade of the crusher spills into the plastic material at a rate of about once a day. It is sufficient to prevent the mixing of metal pieces in the process. Instead of forming the whole spiral shaft (3) with a non-magnetic material, only the portion corresponding to the detection part (7) is made of non-magnetic material, and the material supply side and the material discharge side are made of metal material. These may be integrally connected to form one spiral shaft (3). In addition, by forming the detection unit (7) and the spiral shaft (3) with a material that is a non-magnetic material and an insulator such as plastic, the detection unit (7) and the spiral shaft (3) are connected to the sensor (4 )
Can be further reduced, and the sensor (4) can accurately detect the metal piece. Further, since the magnets (32a) (32b) embedded in the spiral shaft (3) also rotate by the rotation of the spiral shaft (3), the sensor (4) is not affected by the rotation. It is desirable that the coil of (1) is arranged rotationally symmetrically with respect to the rotation axis of the spiral axis (3). Further, the metal piece detecting device (1) in the resin material of the present invention is not limited to the method of transferring the resin material from the material hopper (90) to the heating cylinder (92) of the injection molding machine, It can be used in any device in which it is necessary to remove metal pieces mixed in the material during transportation.

When the metal piece detecting device (1) of the present invention is not used, a material hopper (90) is provided in the upper opening (82) of the through hole (80) to open the opening of the cylinder (2). By closing with a lid or the like, the resin material can be directly supplied from the material hopper (90) to the heating cylinder (92).

The above description of the embodiments is for explaining the present invention, and should not be construed as limiting the invention described in the claims or reducing the scope. or,
The configuration of each part of the present invention is not limited to the above-mentioned embodiment, and it goes without saying that various modifications can be made within the technical scope described in the claims.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a metal piece detection device in a resin material according to the present invention.

FIG. 2 is a sectional view of an essential part showing an embodiment of the present invention.

FIG. 3 is an enlarged view of a main part of FIG. 2;

FIG. 4 is a cross-sectional view showing a conventional metal piece detecting device in a resin material.

[Explanation of symbols]

 (2) Cylinder (3) Spiral shaft (4) Metal sensor (5) Rotation drive device (6) Cylinder material supply section (7) Cylinder detection section (8) Cylinder material discharge section

Claims (6)

[Claims] 1. A material supply part (6) at one end, a material discharge part (8) at the other end, and a detection part formed between the supply part (6) and the discharge part (8) by a non-magnetic material. Cylinder with (7) (2)
A spiral shaft (3) formed of a non-magnetic material is rotatably provided therein, and a rotary drive device (5) is connected to the spiral shaft (3), and a detection unit (7) of the cylinder (2) is provided. A metal sensor (4) for detecting an electrical change of the coil is generated on the outer periphery of the coil by using a coil to generate an oscillating magnetic field or a stationary magnetic field in the detecting unit (7) and using the coil or another coil. Device for detecting metal fragments in the deployed resin material. 2. A material supply unit (6) at one end, a material discharge unit (8) at the other end, and a detection unit formed of a non-magnetic material between the supply unit (6) and the discharge unit (8). Cylinder with (7) (2)
A spiral shaft (3) formed of a non-magnetic material is rotatably provided therein, and a rotary drive device (5) is connected to the spiral shaft (3), and a detection unit (7) of the cylinder (2) is provided. A metal sensor (4) for detecting an electrical change of the coil is generated on the outer periphery of the coil by using a coil to generate an oscillating magnetic field or a stationary magnetic field in the detecting unit (7) and using the coil or another coil. Deploy and detect
At least one permanent magnet (32b) is provided on the shaft portion (30) between the spiral blades (31) of the spiral shaft (3) on the discharge portion (8) side or the supply portion (6) side away from (7). The device for detecting metal fragments in a resin material according to claim 1, wherein (32a) is embedded. 3. An alarm (41) is electrically connected to a metal sensor (4) and the alarm (41) is activated by the operation of the sensor (4).
The metal piece detecting device in the resin material according to claim 1 or 2, wherein the metal piece detecting device operates. 4. The metal sensor (4) is electrically connected to the rotary drive device (5), and the detection unit is activated by the operation of the sensor (4).
The metal piece detection device for a resin material according to any one of claims 1 to 3, wherein the rotation of the spiral shaft (3) is stopped when the metal piece is mixed in the resin material in (7). 5. A switchgear (84) is provided at the material discharge port (81) of the material discharger (8) of the cylinder (2), and the switchgear (84) is provided.
And the metal sensor (4) are electrically connected to each other, and when the operation of the sensor (4) detects the mixing of the metal piece in the resin material in the detection part (7), the switchgear (84) causes the material discharge port to open. The metal piece detecting device in a resin material according to any one of claims 1 to 4, wherein (81) is closed. 6. The material hopper (90) of the resin molding machine is connected to the material supply port (60) of the material supply section (6) of the cylinder (2), and the material discharge section (8) of the cylinder (2) is connected. An injection molding machine equipped with a device for detecting metal fragments in a resin material, in which a material discharge port (81) is connected to a heating cylinder (92) of the resin molding machine.