JPH021551B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention has a chute tube that guides a material to be sorted such as plastics from an upstream side to a downstream side, and when the material to be sorted passes through the shute tube, By switching the passage of the material to be sorted using a detection signal from a coil that is wound around the coil and detects passage of the metal mixed in the material to be sorted, the material to be sorted in which the metal is mixed and the metal are separated. The present invention relates to an improvement of a metal sorting device that sorts materials into unmixed substances.

As shown in FIG. 1, a conventional metal sorting device, such as that seen in Japanese Utility Model Publication No. 50-26151, has a hopper 1 and a swinging section 2 on the lower side. It is roughly composed of a chute tube 4 that guides the sorted material 3 downward, and a detection coil 5 wound around the shute tube 4, and when the material 3 to be sorted mixed with metal 6 passes through the shute tube 4. When the coil 5 detects the impedance change that occurs at that time and generates a pulse signal, this pulse signal is amplified by the amplifier 7 and operates the solenoid 8. When the swinging portion 2 swings from the non-metal receiving container 10 to the metal receiving container 11, the metal 6
It is known that the substance 3 to be sorted is separated into a substance 3 to be sorted in which metals 6 are mixed and a substance 3 to be sorted only in which non-metal 12 is not mixed.

By the way, in the conventional device as described above, the shute tube 4 was formed to extend straight downward, so if the gold 6 mixed in the material to be sorted 3 passed through the center of the shute tube 4, that is, the coil 5, , the metal 6 passes relatively far away from the coil 5, which reduces the accuracy of detecting the metal 6 by the coil 5, making it difficult to accurately sort the metal 6. . In this case, if the diameter of the chute tube 4 is made small so that even if the metal 6 passes through the center of the coil 5, the metal 6 can pass relatively close to the coil 5, the material 3 to be sorted can pass through the chute tube. A so-called bridging phenomenon occurs in which the substance 4 becomes clogged, and the smooth flow of the substance 3 to be sorted is stopped.

Further, in the conventional apparatus described above, since the shute tube 4 was formed to extend vertically downward throughout the entire tube, there was also a drawback that the length of the shute tube 4 prevented the apparatus from being made more compact.

The present invention has been made in order to eliminate the above-mentioned drawbacks, and it is possible to improve the detection accuracy of the coil for detecting metals mixed in the materials to be sorted, to make the device more compact, and to improve the sorting accuracy. The purpose is to provide.

For this reason, the present invention has a shute tube that guides the material to be sorted from the upstream side to the downstream side, and when the material to be sorted passes through the shute tube, a coil wound around the shute tube is used. In a metal sorting device, the metal sorting device detects a metal mixed in the substance to be sorted, and sorts the substance into a substance to be sorted in which the metal is mixed and a substance to be sorted in which the metal is not mixed,
The invention is characterized in that the shute tube is formed with a bent portion that changes the flow direction of the substance to be sorted, and the coil is wound around the bent portion.

An embodiment of the present invention will be described below based on the drawings. In the illustrated embodiment, components that are the same as those of the conventional device shown in FIG. 1 will be described with the same reference numerals as those of the conventional device.

In FIG. 2, a pulverizer (not shown) is installed above the hopper 1 to pulverize molded products of materials 3 to be sorted, such as plastics. The material 3 to be sorted is automatically or semi-automatically conveyed directly into the hopper 1. A chute pipe 4 is connected to the hopper 1, and the shute pipe 4 has the role of guiding the material 3 to be sorted from the upstream side to the downstream side. A swinging portion 2 is provided which is capable of swinging between a non-metallic receiving container 10 and a metal receiving container 11.

In addition, the shute pipe 4 is formed with a bent portion 13 unlike the conventional one, so that the flow direction of the substance 3 to be sorted can be changed from a vertical direction to an oblique direction, and further from the oblique direction to a vertical direction. It is equipped with a sloping part. A detection coil 5 is wound around the bent portion 13 having the inclined portion at a portion where the flow direction of the substance 3 to be sorted is changed to a vertical direction or an oblique direction, and an alternating current voltage is applied to this coil 5. has been done. Therefore, when the substance to be sorted 3 mixed with metal 6 passes through the chute tube 4, the change in impedance that occurs at that time is detected by the coil 5, thereby detecting the metal 6. It's becoming like that.

To briefly describe this principle, when a metal 6 passes through the coil 5 to which an alternating current voltage is applied, an eddy current is generated inside the metal 6, and the coil 5 detects the change in impedance at that time. The passage of the metal 6 can be detected by generating a pulse signal.

In this case, when the metal 6 passing through the coil 5 is a magnetic metal such as iron, the impedance becomes larger than when only the non-metal 12 passes, as shown in FIG. Conversely, when it is a non-magnetic metal, the impedance is small. Moreover, when a magnetic metal passes through it together, the impedance becomes large, of course. Therefore, regardless of whether the metal 6 passing through the coil 5 is a magnetic metal or a non-magnetic metal, the metal 6 can be detected by changing the impedance.

In addition, 7 is an amplifier that amplifies the pulse signal generated by the coil 5, and 8 is a solenoid that is operated by the pulse current amplified by the amplifier 7. When this solenoid 8 receives the pulse signal,
The swinging section 2 is set to swing from the non-metal receiving container 10 to the metal receiving container 11 via the swinging arm 9.

Next, the operation of the above-mentioned constituent device will be explained.

After the material 3 to be sorted, which has been pulverized by the pulverizer, is automatically or semi-automatically conveyed into the hopper 1 and falls from the hopper 1, the material 3 to be sorted is transferred to the upstream side by the chute pipe 4. guided downstream from When the substance 3 to be sorted passes through the shute pipe 4, the impedance of the substance 3 to be sorted is detected by the coil 5 wound around the bent part 13 having an inclined portion. metal 6
If the metal 6 passes through the bent portion 13 with an inclined portion, the impedance changes, and the coil 5 generates a pulse signal to detect that the metal 6 has passed through the bent portion 13 with an inclined portion. Next, the pulse signal generated by the coil 5 is amplified by the amplifier 7 as in the conventional case, and when the solenoid is operated, the swing arm 9
The swinging unit 2 swings from the non-metal receiving container 10 to the metal receiving container 11 via the metal receiving container 10, and the material to be sorted 3 containing metals 6 is reliably sorted and accommodated in the metal receiving container 11. . Then, when the material 3 to be sorted, consisting only of non-metals 12 and no metals 6, passes through,
Now that the impedance is constant,
The coil 5 does not generate a pulse signal and the swing arm 9
The swinging part 2 returns to the non-metal receiving container 10 again via the , and the material to be sorted 3 consisting of only the non-metal 2 without any metal 6 mixed therein is sorted and accommodated in the non-metal receiving container 10. .

As described above, since the coil 5 is wound around the bent portion 13 having the inclined portion, the detection accuracy of the metal 6 by the coil 5 is improved more than ever for the following reasons. That is, since the non-metal 12 and the metal 6 have different coefficients of repulsion, as shown in FIG. , the non-metal 12 with a large coefficient of repulsion repels the lower slope farther away than the metal with a smaller coefficient of repulsion and changes the direction of the flow. Therefore, a partial flow barrier is formed in which almost only the non-metal 12 gathers on the upper passage side in the bent portion 13 having the inclined portion, and this flow barrier due to the non-metal 12 is This results in substantially reducing the flow path of the metal 6 toward the lower slope side. In other words, the metal 6 passes through a space passage substantially constituted by the flow barrier formed by the non-metal 12 and the lower inner surface of the bent portion 13 having an inclined portion, and the metal 6 passes through the coil. The probability that the metal 6 will pass through a part of the coil 5 that is deviated downward from the center is extremely high, and as a result, the metal 6 will pass relatively closer to the coil 5 than in the past. Therefore, by bringing the metal 6 relatively closer to the coil 5, the detection accuracy of the coil 5 can be improved without reducing the diameter of the chute tube 4.

In addition, since the bent portion 13 having an inclined portion is formed in the shute pipe 4, if the angle of inclination of the inclined portion of the bent portion 13 is θ, and the pipe length of the bent portion 13 is h, the shute pipe 4 can be straightly moved vertically downward. The length of the chute tube 4 can be reduced by h x (1-
sinθ). The material to be sorted 3 in the bending part 13 which actually has an inclined part
For reasons such as the passing speed being slower than the speed when falling naturally through the chute tube 4 of the conventional device,
The length of the chute tube 4 can be made shorter than the above value.

Furthermore, since the swinging arm 9 has mass, the operation of the solenoid 8 cannot avoid a response delay, and this response delay may delay the swinging of the swinging arm 9. However, since this device has the bent portion 13 with an inclined portion, the passing speed of the substance 3 to be sorted through the bent portion 13 with the inclined portion as described above is lower than that of the chute tube of the conventional device. 4 is set to be slower than the speed at which the metal 6 falls naturally, so that after the coil 5 detects the metal 6, the swing arm 9 swings from the non-metal receiving container 10 to the metal receiving container 11. Since the material to be sorted 3 containing metal 6 does not pass through, the sorting accuracy can be further improved.

Incidentally, the inclination angle θ of the inclined portion of the chute tube 4 according to the present invention is desirably 40 degrees to 45 degrees or more in order to prevent the substance 3 to be sorted from causing a bridging phenomenon in the chute tube 4 and clogging it. This inclination angle θ
Of course, the value varies depending on conditions such as the magnitude of the restitution coefficient of the substance 3 to be sorted.

As explained above, according to the present invention, the bent part that changes the direction of flow of the material to be sorted is formed in the chute pipe that guides the material to be sorted from the upstream side to the downstream side, and the inclined part is provided. A detection coil is wound around the bent portion to separate the material to be sorted into a material mixed with metals and a material to be sorted without the metal mixed therein. After colliding with the inner surface, non-metals with a large coefficient of repulsion repel the inner surface farther away than metals with a smaller coefficient of repulsion, changing the flow direction, so that almost only non-metals pass through the bend. A partial flow barrier is formed where the metal is concentrated, and this increases the probability that the metal will pass through the coil at a point that is offset to one side from the center of the coil. Therefore, the detection accuracy of the coil can be improved without reducing the diameter of the chute tube, and metals can be sorted more accurately than before.

In addition, since the chute tube has a bent portion with an inclined portion, the length of the chute tube can be shortened at the bent portion compared to conventional devices in which the chute tube is formed vertically downward, making the device more compact. At the same time, the speed at which the material to be sorted passes through the bent portion with the inclined portion is slower than the speed at which it naturally falls through the chute tube of the conventional device. Since the material to be sorted containing metals does not pass through the sorting means before responding, there is also the effect that sorting accuracy can be further improved.

[Brief explanation of drawings]

Fig. 1 is a front view showing a conventional metal sorting device, Fig. 2 is a front view showing an embodiment of the present invention, Fig. 3 is a front sectional view showing the main parts of Fig. 2, and Fig. 4 is a coil. FIG. 3 is a characteristic diagram showing the magnitude of impedance detected by the sensor. 3...Substance to be sorted, 4...Chute tube, 5...
Coil, 6...metal, 13...bending part.

Claims (1)

[Scope of Claims] 1. A chute tube that guides a substance to be sorted from an upstream side to a downstream side, and when the substance to be sorted passes through the chute tube,
By switching the passage of the material to be sorted using a detection signal from a coil that is wound around the shute pipe and detects passage of metal mixed in the material to be sorted, the material to be sorted is mixed with the metal; In the metal sorting device which separates the material to be sorted and the material to be sorted in which metals are not mixed, a bent portion having an inclined portion that changes the flow direction of the material to be sorted is formed in the shute pipe, and a bent portion is formed in the bent portion. A metal sorting device characterized in that the coil is wound.