JP2010113838A - Pellet supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pellet supply device capable of effectively destaticizing the inside of a sight glass. <P>SOLUTION: The pellet supply device consists of a hopper 2 for housing pellets, a sight glass 1 connecting the hopper and a molding device 7, and a static eliminator 200 destaticizing the inside of the sight glass. The static eliminator 200 consists of a pipe with a through-hole formed in an axis direction and with one end located inside the sight glass, and a self-discharge electrode made of a conductive material, of which, the self-discharge electrode is fitted to the pipe so as its tip to overlap with the through-hole in an axis direction of the pipe. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a pellet supply apparatus, and more particularly, to a pellet supply apparatus that can effectively neutralize pellets supplied to an injection molding apparatus.

  Conventionally, in the process of handling insulator particles and insulator powders, charged particles, powders, fine fragments, pellets, etc. (hereinafter, referred to as “prevention of troubles due to static electricity, improvement of quality and yield”, etc.) A neutralization system is used for neutralizing the inside of a pipe line that transports the charged particles) or a container in which these charged particles are accumulated.

  For example, a voltage application type static eliminator such as an AC static eliminator performs static elimination by blowing positive and negative ions generated from an electrode to which a high voltage is applied in an air stream. If positive and negative ions can be supplied in a well-balanced manner, the charge removal capability in the vicinity where ions are ejected can be made extremely high.

  However, since the ejected positive and negative ions are recombined, the neutralization capability decreases as the time after ejection elapses, that is, as the distance from the neutralizer increases.

  From such a background, Patent Documents 1 and 2 as a method for removing the charge of the charged particles in the pipe and the container pass through the pipe by attaching a special corona discharge electrode to the side of the pipe. Methods for neutralizing charged particle groups, Patent Documents 3 and 4, respectively, propose a method of disposing a voltage application type static eliminator on the side surface of a container for storing powder. All of these methods are intended to effectively remove static electricity by bringing the generation source of static elimination ions closer to the charged particle group.

  However, in these voltage application type static eliminators, since a high voltage is always applied to the corona discharge electrode, there are problems such as ignition due to mixing of particles into the electrode portion and high voltage leakage due to insulation deterioration between the electrodes. May occur.

  In addition, it is inevitable that the ability to remove static electricity is deteriorated due to electrode deterioration and wear due to discharge, and the ion balance is deteriorated due to electrode wear.

  When the ion balance is deteriorated, not only the charge removal ability is greatly reduced, but also the particles to be discharged are positively charged. In order to avoid such a situation, it is necessary to periodically maintain the electrodes in a short cycle.

  Moreover, in order to send positive and negative ions generated at the electrode part effectively to the outside of the electrode by an air flow, a large air volume is required.

  On the other hand, when the object to be neutralized forms a sufficiently high electric field in the surroundings, simply bringing a grounded electrode (self-discharge electrode) close to it causes a corona discharge with a polarity opposite to that of the charged object to occur from the ground electrode. The object can be neutralized by this corona discharge. A static eliminator based on such a principle is called a self-discharge type static eliminator.

  However, since the self-discharge electrode does not operate unless the electric field around the tip of the electrode becomes equal to or higher than the corona discharge start electric field, there is a problem that it is difficult in principle to neutralize all charges of the charged object.

  However, with the self-discharge type static eliminator, it is possible to perform static elimination to the extent that adverse effects such as scattering and adhesion of charged particles due to electricity do not appear.

  In addition, the self-discharge type static eliminator has a simple structure compared to the voltage application type static eliminator, and further, since the static elimination ions are supplied only when the static elimination target is largely charged, deterioration and wear caused by discharge There are many advantages that can be greatly reduced, and maintenance costs can be greatly reduced.

  Until now, the thing of various structures has been proposed as a self-discharge electrode used for a self-discharge type static eliminator.

  For example, Patent Document 5 proposes a self-discharge electrode in which a large number of convex portions are formed on one long side of a tape made of a sheet containing conductive fibers.

  Patent Document 6 proposes a self-discharge electrode using spiral twisted yarn.

  Patent Document 7 proposes a self-discharge electrode in which a non-metallic fiber is coated with a metal coating.

  All of these self-discharge electrodes are premised on being applied mainly to charged sheet-like or plate-like insulators, or charged bodies distributed in a plane.

  That is, in each of Patent Documents 5 to 7, the static charge is widely distributed three-dimensionally, such as a conduit through which the charged particle group passes or a container in which the charged particle group accumulates, and the electrostatic attraction force. No mention is made of application to an environment in which charged particles move toward the self-discharge electrode.

  One example in which charged particles have a great adverse effect on product quality due to electrostatic force is a group of resin pellets used for injection molding. In a system for supplying resin pellets to an injection molding machine, a static phenomenon in a sight glass of a hopper with a sight glass causes a big problem.

  A hopper with sight glass is a part of a device for supplying resin pellets to an injection molding machine, and is widely used in a factory where plastic molding is performed.

  In particular, when using a hygroscopic resin such as polycarbonate resin, acrylic resin, etc., the moisture content in the resin is reduced by a drying device to the extent that it does not cause a problem when heated and melted in the molding process, and immediately before entering the molding machine. At this stage, it is stored in a hopper with a sight glass and supplied to a molding machine at a certain rate while performing sensing.

  FIG. 11 is a cross-sectional view of a pellet supply device for supplying pellets (resin) to the molding device 7.

  The pellet feeder shown in FIG. 11 includes a hopper 2 that stores dried pellets (resin) 5 before being put into the molding device 7, a suction device 3 that sucks the pellets 5 into the hopper 2, and a pellet 5. A supply pipe 4 for supplying the inside of the hopper 2, and a sight glass (glass tube) for connecting the hopper 2 and the molding device 7, and visually checking the supply state of the pellets 5 from the hopper 2 to the molding device 7. The sight glass 1 is configured to be opposed to the sight glass 1, and the capacitance type sensor 6 is disposed to determine whether or not the pellet 5 from the hopper 2 needs to be supplied.

  In the process in which the pellet 5 is supplied into the sight glass 1 through the pipe 4 and the hopper 2, the pellet 5 is charged by collision and friction with the supply pipe 4 and the wall surface of the hopper 2, and has various adverse effects.

  For example, (1) the pellet 5 sticks to the inner wall of the sight glass 1 and causes the capacitive sensor 6 to malfunction. (2) The pellet 5 remaining on the sight glass 1 is mixed with the subsequent pellet 5 to lower the quality. (3) Only the master batch mixed in the matrix resin is stuck to the sight glass 1 to cause uneven color at the time of molding.

  Japanese Patent Laid-Open No. 8-39566 (Patent Document 8) proposes a method for preventing charging of the resin in such a resin supply apparatus.

  In the method proposed in Patent Document 8, after pellets 5 are supplied to the hopper 2, the hopper 2 is closed and passed through a dust collector, and the inside of the hopper 2 is blown for a predetermined time with the air that has been dried and discharged. Thereafter, the closed system of the hopper 2 is released, and the pellets 5 are supplied to the molding device 7.

Moreover, it is also possible to neutralize the pellet 4 in the piping 4 or the hopper 2 by the method disclosed in Patent Documents 1 to 4.
Japanese Patent Laid-Open No. 3-15316 Japanese Patent No. 3686944 Japanese Patent Laid-Open No. 2005-1818 JP 2003-267484 A JP 2003-109793 A JP 2000-73244 A JP-A-8-288093 JP-A-8-39566

  However, in any of these methods, the neutralization of the inside of the sight glass 1 located under the hopper 2 is not considered, and even if triboelectric charging occurs between the inner wall of the sight glass 1 and the pellet 5. This cannot be effectively neutralized.

  Actually, since the pellet 5 is once stored in the glass tube and then supplied to the molding apparatus 7, the charging inside the sight glass 1 may greatly affect the characteristics of the pellet 5 entering the molding apparatus 7. Rather, since the pellets 5 supplied to the hopper 2 are sequentially accumulated from the inside of the sight glass 1, the charge removal in the sight glass 1 is more important than the charge removal in the hopper 2.

  This inventor measured the electrostatic potential of the side surface of the sight glass 1 in the process in which the pellet (resin) 5 is intermittently supplied to the sight glass 1 in the resin supply system for an injection molding machine.

  As a result, a positive high voltage is generated in the process in which the pellet 5 accumulates inside the sight glass 1, and conversely, the pellet 5 stored inside the sight glass 1 falls while rubbing against the glass surface. In the process, it was found that positive or negative high voltage is generated on the surface of the sight glass 1 by frictional charging.

  In the intermittent pellet supply process, as a result of the situation in which the positively charged pellet 5 is supplied to the negatively charged hollow sight glass 1, the pellet 5 is stuck to the inner wall of the sight glass 1. Is causing such problems.

  In order to alleviate the above-described charging phenomenon inside the sight glass 1, it is incomplete by the charge removal inside the hopper 2 as shown in Patent Document 8, and the inside of the sight glass 1 is effectively removed. There is a need to.

  The present invention has been made in view of the problems in such a conventional resin supply system for an injection molding machine, and provides a pellet supply apparatus that can effectively neutralize the inside of the sight glass. With the goal.

  In order to achieve the above object, the present invention provides a pellet feeder comprising: a hopper that contains pellets; a sight glass that connects the hopper and a molding device; and a static eliminator that neutralizes the inside of the sight glass. The static eliminator is a pipe in which at least one through hole is formed in the axial direction, one end of which is located in the sight glass, and a conductive material, and the same number as the through hole. The self-discharge electrode is attached to the pipe such that the tip of the self-discharge electrode overlaps the through hole corresponding to the self-discharge electrode in the axial direction of the pipe A pellet feeder is provided.

  The self-discharge electrode is preferably attached to the pipe such that a tip of the self-discharge electrode overlaps with the center of the through hole corresponding to the self-discharge electrode in the axial direction of the pipe.

  The present invention further comprises a pellet supply device comprising a hopper for storing pellets, a sight glass connecting the hopper and a molding device, and a static eliminator for neutralizing the inside of the sight glass, wherein the static eliminator Is a pipe in which at least one through-hole is formed in the axial direction, one end of which is located in the sight glass, and a self-discharge electrode made of a conductive material. The self-discharge electrode is attached to the pipe so that each of the tip parts overlaps the corresponding through-hole in the axial direction of the pipe. A pellet feeder is provided.

  The self-discharge electrode is preferably attached to the pipe so that each of the tip portions overlaps the center of the corresponding through hole in the axial direction of the pipe.

  Preferably, the self-discharge electrode is grounded, or an alternating bias voltage is applied to the self-discharge electrode.

  The present invention further comprises a pellet supply device comprising a hopper for storing pellets, a sight glass connecting the hopper and a molding device, and a static eliminator for neutralizing the inside of the sight glass, wherein the static eliminator Is a pipe in which at least one through hole is formed in the axial direction, one end of which is a pipe located in the sight glass, the pipe is made of a conductive material, and one end of the pipe is pointed An extension body is formed, and the extension body provides a pellet supply apparatus that is bent so that a tip of the extension body overlaps the through hole corresponding to the extension body in the axial direction of the pipe.

  The extension body is preferably bent so that the tip of the extension body overlaps the center of the through hole corresponding to the extension body in the axial direction of the pipe.

  It is preferable that the one end of the pipe has a surface inclined with respect to the central axis of the pipe, and the extension body is formed at a position on the most distal end side of the inclined surface.

  The pipe and the extension body are preferably integral.

  The pipe is made of a metal hollow pipe having an outer diameter of 3 mm or less, for example.

  It is preferable that the pipe is grounded or an AC bias voltage is applied to the pipe.

  It is preferable that the static eliminator further includes an insulating layer covering an outer surface of the pipe.

  The pipe preferably has a structure that can expand and contract in its axial direction.

  It is preferable that the static eliminator further includes an insulator cover made of an insulating material and spaced from the pipe to cover the periphery of the pipe.

  The insulator cover is preferably made of a material that charges the charged body in contact with the insulator cover with a reverse polarity.

  According to the self-discharge type static eliminator according to the present invention, static charges can be effectively removed inside the sight glass connecting the hopper and the molding apparatus.

  In addition, by emitting an air flow to the self-discharge electrode, it is possible to prevent a situation in which charged particle groups adhere to the self-discharge electrode and interfere with the occurrence of self-discharge.

(First embodiment)
FIG. 1 is a cross-sectional view of a pellet supply apparatus 100 according to the first embodiment of the present invention.

  The pellet supply apparatus 100 according to the present embodiment is disposed above the molding apparatus 7 and supplies pellets (resin) to the molding apparatus 7.

  As shown in FIG. 1, the pellet supply apparatus 100 according to the present embodiment sucks the dried pellet (resin) 5 before being put into the molding apparatus 7 and sucks the pellet 5 into the hopper 2. A sight glass (glass tube) for connecting the hopper 2 and the molding device 7, the suction device 3 for supplying the pellet 5 to the inside of the hopper 2, and the molding device 7. A sight glass 1 for visually confirming the supply state of the pellets 5 until, and a capacitance type sensor 6 disposed opposite to the sight glass 1 for determining whether or not the pellets 5 from the hopper 2 need to be supplied; , The static eliminator 200.

  FIG. 2 is a perspective view showing the static eliminator 200.

  As shown in FIG. 2, the static eliminator 200 includes a pipe (that is, a hollow pipe) 210 in which a through hole 211 is formed in the axial direction, and a self-discharge electrode 220.

  As shown in FIG. 1, the static eliminator 200 is attached to the top surface of the hopper 2 via a fixture 212.

  Further, as shown in FIG. 1, the lower end of the pipe 211 reaches the inside of the sight glass 1, and the upper end penetrates the top surface of the hopper 2 and protrudes outside the hopper 2.

  The pipe 211 is connected to the air flow generating means 230 via the bellows hose 213 at the upper end protruding outside the hopper 2.

  The air flow generation means 230 is composed of, for example, a pump, and the air flow generated by the air flow generation means 230 and made of air outside the pellet supply device 100 is supplied to the through hole 211 of the pipe 210 via the bellows hose 213. It has become so.

  The pipe 210 is a commercially available vinyl chloride pipe.

  The self-discharge electrode 220 is made of a metal wire and is attached to the lower end of the pipe 210. The self-discharge electrode 220 has a quadrant shape, and is attached to the pipe 210 at one end, and the other end forms a free end. The self-discharge electrode 220 is attached to the pipe 210 such that the tip thereof overlaps the through hole 211 in the axial direction of the pipe 210.

  The pellet supply apparatus 100 according to the present embodiment having the above structure operates as follows.

  The suction device 3 supplies the pellet 5 into the hopper 2 through the supply pipe 4.

  The pellets 5 housed inside the hopper 2 fall into the molding apparatus 7 through the sight glass 1 due to their own weight.

  As described above, the pellet 5 is charged by the collision / friction with the supply pipe 4, the hopper 2, or the wall surface of the sight glass 1 before being put into the molding apparatus 7.

  As a result, an electric field is generated inside the site glass 1 due to the charge of the pellet 5. The intensity of this electric field increases as the amount of charge inside the sight glass 1 increases.

  When the strength of the electric field inside the sight glass 1 becomes sufficiently strong, that is, when the strength of the electric field inside the sight glass 1 exceeds the threshold value, the self-discharge electrode 220 starts self-discharge. Specifically, corona discharge is generated from the tip (free end) of the self-discharge electrode 220.

  Since this corona discharge includes charges (ions) having a polarity opposite to the polarity of the charges existing inside the sight glass 1, the charges of this corona discharge are different from the charges existing inside the sight glass 1. When combined, both charges are electrically neutralized. That is, the charge contained in the corona discharge generated from the self-discharge electrode 220 can act as a charge-removing ion for the charge existing inside the site glass 1.

  The air flow generation means 230 discharges an air flow composed of air outside the pellet supply apparatus 100 to the self-discharge electrode 220 through the through hole 211 of the pipe 210.

  For this reason, static-removing ions contained in the corona discharge generated from the self-discharge electrode 220 ride on the air flow supplied from the air flow generating means 230 and are transported throughout the interior of the sight glass 1 and exist in the sight glass 1. The charged particles are combined with the charge of the charged particle group to electrically neutralize the charge inside the sight glass 1.

  As a result, the charge existing inside the sight glass 1 can be eliminated.

  As described above, according to the pellet supply apparatus 100 according to the present embodiment, the static charge inside the sight glass 1 can be effectively removed.

  In addition, when the air flow from the air flow generating means 230 is radiated to the self-discharge electrode 220 through the through-hole 211, the charged pellet 5 adheres to the self-discharge electrode 220 and disturbs the occurrence of self-discharge. Can be prevented.

  The pellet supply apparatus 100 according to the present embodiment is not limited to the above structure, and various modifications can be made.

  In the pellet supply apparatus 100 according to the present embodiment, the self-discharge electrode 220 is made of a metal wire, but the material of the self-discharge electrode 220 is not limited to metal. Any conductive material can be selected. Further, the shape of the self-discharge electrode 220 is not limited to a linear shape, and may be another shape, for example, a thin plate shape.

  From the viewpoint of safety, the self-discharge electrode 220 is preferably grounded. Alternatively, an alternating bias voltage is preferably applied to the self-discharge electrode 220. By applying an alternating bias voltage, the intensity of the electric field formed at the tip of the self-discharge electrode 220 by the charged particle group is increased, so that corona discharge can be more effectively caused.

  Further, by providing a solenoid valve in the air flow generation means 230, it is possible to intermittently supply air from the air flow generation means 230 to the self-discharge electrode 220.

  In the pellet supply apparatus 100 according to the present embodiment, the pipe 210 is configured as a commercially available vinyl chloride pipe. However, any pipe having a hole corresponding to the through hole 211 may be used instead of the pipe 210. Shaped ones can be used.

  The material of the pipe 210 is not limited to an insulating material, and a pipe made of a conductive material can be used.

  In the pellet supply apparatus 100 according to the present embodiment, the self-discharge electrode 220 is arranged so that the tip of the self-discharge electrode 220 overlaps the through hole 211 in the axial direction of the pipe 210. Most preferably, the pipe 210 overlaps the center of the through hole 211 in the axial direction.

  Since the center of the through-hole 211 is the position where the flow velocity of the airflow from the airflow generating means 230 is the highest, the tip of the self-discharge electrode 220 is discharged from the tip of the self-discharge electrode 220 by overlapping the tip of the self-discharge electrode 220 with the center of the through-hole 211. The corona discharge generated can be more effectively diffused.

  Moreover, in the pellet supply apparatus 100 according to the present embodiment, the upper end of the pipe 210 penetrates the top surface of the hopper 2 and protrudes to the outside of the hopper 2, but the upper end of the pipe 210 is the inner wall of the top surface of the hopper 2. It is also possible to send the air flow from the air flow generation means 230 from the upper end of the pipe 210 via the bellows hose 213.

(Second embodiment)
FIG. 3 is a perspective view of a static eliminator 300 used in the pellet supply apparatus according to the second embodiment of the present invention.

  The pellet supply apparatus according to the present embodiment has the same structure as the pellet supply apparatus 100 according to the first embodiment except that a static eliminator 300 is used instead of the static eliminator 200.

  As shown in FIG. 3, the static eliminator 300 according to the present embodiment includes a pipe 310 in which five through holes 311 are formed in the axial direction, and the same number of through holes 311, that is, five self-discharge electrodes 320. , Is composed of.

  One of the five through-holes 311 is formed with the center of the bottom surface of the pipe 310 as the center, and the other four are so as to have an equicircular angle on a concentric circle with the center of the bottom surface of the pipe 310 as the center. Is formed.

  The pipe 310 is a commercially available vinyl chloride pipe.

  Each self-discharge electrode 320 is made of a metal wire and is attached to the lower end of the pipe 310. Specifically, each self-discharge electrode 320 has a quadrant shape, and is attached to the pipe 310 at one end thereof and the other end forms a free end. Each self-discharge electrode 320 is attached to the pipe 310 such that the tip of the self-discharge electrode 320 overlaps the through-hole 311 corresponding to the self-discharge electrode 320 in the axial direction of the pipe 310.

  An air flow made of air outside the pellet supply device generated by the air flow generation means 230 is supplied to each through hole 311 of the pipe 310.

  The self-discharge type static eliminator 300 according to this embodiment having the above-described structure operates as follows.

  Each self-discharge electrode 320 generates corona discharge from its tip in the same manner as the self-discharge electrode 220 in the first embodiment.

  The air flow generating means 230 discharges an air flow composed of the outside air of the pellet supply device to each self-discharge electrode 320 through each through hole 311 of the pipe 310.

  For this reason, static elimination ions included in the corona discharge generated from each self-discharge electrode 320 ride on the air flow supplied from the air flow generation means 230 and are transported throughout the site glass 1. Combined with the existing charge, the charge inside the sight glass 1 is electrically neutralized.

  As a result, the charge existing inside the sight glass 1 can be eliminated.

  As mentioned above, according to the pellet supply apparatus which concerns on this embodiment, since there are many self-discharge electrodes 320 compared with the pellet supply apparatus 100 which concerns on 1st embodiment, the sight glass 1 is more efficiently. The electrostatic charge inside can be removed.

  The static eliminator 300 in the present embodiment is not limited to the above structure, and various modifications can be made.

  In the static eliminator 300 according to the present embodiment, the pipe 310 is configured as a commercially available pipe made of vinyl chloride. However, as long as the pipe 310 has a hole corresponding to the through hole 311, any shape can be used instead of the pipe 310. Can be used.

  The material of the pipe 310 is not limited to an insulating material, and a pipe made of a conductive material can be used.

  Further, the number of through-holes 311 formed in the pipe 310 and the number of self-discharge electrodes 320 corresponding to each through-hole 311 are not limited to five, and an arbitrary number of two or more can be selected. Is possible.

(Third embodiment)
FIG. 4 is a perspective view of a static eliminator 400 used in the pellet supply apparatus according to the third embodiment of the present invention, and FIG. 5 is a bottom view of the static eliminator 400 when viewed from the direction A in FIG. .

  The pellet supply apparatus according to the present embodiment has the same structure as the pellet supply apparatus 100 according to the first embodiment except that a static eliminator 400 is used instead of the static eliminator 200.

  As shown in FIGS. 4 and 5, the static eliminator 400 according to this embodiment includes a pipe 410 having four through holes 411 formed in the axial direction and a self-discharge electrode 420.

  The four through holes 411 are formed at equal circumferential angles on concentric circles centering on the center of the bottom surface of the pipe 410.

  The self-discharge electrode 420 includes a linear straight portion 421 that extends downward from the center of the bottom surface of the pipe 410 and four arc-shaped portions 422 that extend in four directions from the tip of the straight portion 421 (lower end in FIG. 4). Has been. Both the straight portion 421 and the arc-shaped portion 422 are made of metal wires.

  The direction of each arc-shaped portion 422 is adjusted so that the tip of the arc-shaped portion 422 overlaps the through-hole 411 corresponding to the arc-shaped portion 422 in the axial direction of the pipe 410.

  The operation principle of the static eliminator 400 in the present embodiment having the above-described structure is the same as that of the static eliminator 200 in the first embodiment or the static eliminator 300 in the second embodiment. The same effect as the static eliminator 300 in the second embodiment is obtained.

(Fourth embodiment)
FIG. 6 is a perspective view of a static eliminator 500 used in the pellet supply apparatus according to the fourth embodiment of the present invention.

  The pellet supply apparatus according to the present embodiment has the same structure as the pellet supply apparatus 100 according to the first embodiment except that a static eliminator 500 is used instead of the static eliminator 200.

  As shown in FIG. 6, the static eliminator 500 in the present embodiment includes a pipe 510 in which a through hole 511 is formed in the axial direction.

  Pipe 510 is made of metal or other conductive material.

  The lower surface of the pipe 510 forms a slope that is inclined with respect to the central axis of the pipe 510. An extension body 520 having a sharp tip 521 is formed at a position on the most tip side of the slope (the lowest position in FIG. 6). The extension 520 is bent so that the tip 521 thereof overlaps the through hole 511 in the axial direction of the pipe 510.

  The extension body 520 can be formed as follows, for example.

  First, a hollow pipe made of a conductive material, for example, a metal is prepared. As such a hollow pipe, a metal hollow pipe having an outer diameter of 3 mm or less is preferable.

  Next, one end of the hollow pipe is sharpened. That is, by cutting the hollow pipe, a thin linear portion is formed from one end of the hollow pipe along the outer surface of the hollow pipe. When cutting the hollow pipe, at the same time, the lower surface of the hollow pipe may be processed into a surface inclined with respect to the central axis of the hollow pipe.

  Next, the linear portion is bent in an arc shape so that the tip of the linear portion overlaps the through hole of the hollow pipe.

  Through the above process, the self-discharge electrode 520 integrated with the pipe 510 can be formed.

  The static eliminator 500 in the present embodiment having the above-described structure operates in the same manner as the static eliminator 200 (FIG. 2) in the first embodiment, and has the same effect as the static eliminator 200 in the first embodiment.

  The static eliminator 500 in the present embodiment is not limited to the above structure, and various modifications can be made.

  In the static eliminator 500 in the present embodiment, the extension body 520 is arranged so that the tip thereof overlaps the through hole 511 in the axial direction of the pipe 510, but the self-discharge type static eliminator according to the first embodiment. As in the case of 200, it is most preferable that the tip of the extended body 520 overlaps the center of the through hole 511 in the axial direction of the pipe 510.

  In the static eliminator 500 according to the present embodiment, the lower surface of the pipe 510 is formed as a slope, but it is not always necessary that the lower surface of the pipe 510 is a slope. The lower surface of the pipe 510 may be a plane similar to the upper surface.

  The extension body 520 is not necessarily integral with the pipe 510. For example, the extension body 520 can be manufactured separately from the pipe 510 and then attached to the lower surface of the pipe 510.

(Fifth embodiment)
FIG. 7 is a perspective view of a static eliminator 600 used in the pellet supply apparatus according to the fifth embodiment of the present invention.

  The pellet supply apparatus according to the present embodiment has the same structure as the pellet supply apparatus 100 according to the first embodiment except that a static eliminator 600 is used instead of the static eliminator 200.

  As shown in FIG. 7, the static eliminator 600 according to this embodiment includes a pipe 610 in which four through holes 611 are formed in the axial direction.

  An extension body 620 similar to the extension body 520 in the fourth embodiment is formed on the lower surface of the pipe 610 corresponding to each through hole 611.

  According to the static eliminator 600 in the present embodiment, the number of the extension bodies 620 that function as self-discharge electrodes is larger than in the static eliminator 500 in the fourth embodiment. Static charges can be removed.

(Sixth embodiment)
FIG. 8 is a perspective view of a static eliminator 700 used in the pellet supply apparatus according to the sixth embodiment of the present invention.

  The pellet supply apparatus according to the present embodiment has the same structure as the pellet supply apparatus 100 according to the first embodiment except that a static eliminator 700 is used instead of the static eliminator 200.

  As shown in FIG. 8, the static eliminator 700 in the present embodiment includes a pipe 510 and a fixing unit 710 that fixes the pipe 510 to the top surface of the hopper 2.

  An extension body 520 is formed at the tip (lower end) of the pipe 510. That is, the pipe 510 constitutes the self-discharge type static eliminator 500 (FIG. 6) according to the fourth embodiment.

  The fixing means 710 includes a cylindrical first fixing tool 711, a cylindrical second fixing tool 712 having the same diameter as the first fixing tool 711, and an electrode support 713.

  The electrode support 713 is constituted by a hollow pipe, and the pipe 510 is disposed in the electrode support 713 at a position concentric with the electrode support 713. The pipe 510 is attached to the electrode support 713 through a hollow joint 715.

  The air flow generated by the air flow generating means 230 is supplied to the through hole 511 of the pipe 510 via the hollow electrode support 713.

  The first fixture 711 is formed with a central through hole through which the electrode support 713 passes along the central axis. Similarly, the second support 712 also passes through the electrode support 713 along the central axis. A central through hole is formed.

  A screw hole 711 a extending horizontally to the through hole is formed in the first fixture 711, and the first fixture 711 is fixed to the electrode support 713 by fitting the screw 716 into the screw hole 711 a. Is done.

  In the second fixture 712, two through holes 712a and 712b extending in parallel with the central through hole are formed around the central through hole.

  When the first fixture 711 is placed on the second fixture 712 on the bottom surface of the first fixture 711 (the surface facing the second fixture 712), two through holes 712a and 712b are provided. Two screw holes 711c and 711d extending on the straight line are formed.

  The second fixing tool 712 is fixed to the first fixing tool 711 by fitting the screws 717a and 717b into the two through holes 712a and 712b and the two screw holes 711c and 711d, respectively.

  The static eliminator 700 in the present embodiment having the above structure is used as follows.

  It is assumed that a hole through which the electrode support 713 is passed and a hole into which the two screws 717a and 717b are fitted are formed on the top surface of the hopper 2.

  First, the pipe 510 is attached to the tip of the electrode support 713 through the hollow joint 715.

  Next, the electrode support 713 is fitted into the central through hole of the second fixture 712.

  In this state, the electrode support 713 is fitted into the hole for the electrode support 713 from the inside of the hopper 2.

  Next, the electrode support 713 is fitted into the through hole of the first fixture 711 outside the hopper 2.

  Next, the two screws 717 a and 717 b are fitted into the through holes 712 a and 712 b and the screw holes 711 c and 711 d to fix the second fixing tool 712 to the first fixing tool 711. In this state, the top surface of the hopper 2 is sandwiched between the second fixture 712 and the first fixture 711.

  Next, the screw 716 is fitted into the screw hole 711 a to fix the first fixture 711 to the electrode support 713.

  As described above, the static eliminator 700 in the present embodiment is fixed to the top surface of the hopper 2.

  The air flow generated by the air flow generation unit 230 passes through the electrode support 713 and is radiated to the corona discharge emitted from the tip of the extension 520 through the through hole 511 of the pipe 510.

  According to the static eliminator 700 in this embodiment, if the screw 716 is loosened, the electrode support 713 and thus the pipe 510 can be slid in the vertical direction. After the electrode support 713 is moved up and down, the screw 716 is moved. By tightening, it is possible to fix the electrode support 713 and thus the pipe 510 in a desired position.

  Thereby, the position of the extension body 520 formed at the tip of the pipe 510, that is, the position where the corona discharge is generated can be moved up and down inside the sight glass 1, and the position where the electric field strength is greatest inside the sight glass 1. In this case, corona discharge can be generated.

  In the static eliminator 700 according to this embodiment, the fixing means 710 for fixing the pipe 510 to the top surface of the hopper 2 includes a first fixing tool 711 and a second fixing tool 712. The structure of the fixing means 710 is as follows. This is not a limitation. The fixing means 710 can have any structure as long as the electrode support 713 can be attached to the top surface of the hopper 2 so that the electrode support 713 can move up and down.

  In the static eliminator 700 according to the present embodiment, the electrode support 713 and the pipe 510 are connected to each other via the hollow joint 715. However, the electrode support 713 and the pipe 510 are integrated. Is also possible.

(Seventh embodiment)
FIG. 9 is a perspective view of a static eliminator 800 used in the pellet supply apparatus according to the seventh embodiment of the present invention.

  The pellet supply apparatus according to the present embodiment has the same structure as the pellet supply apparatus 100 according to the first embodiment except that a static eliminator 800 is used instead of the static eliminator 200.

  As shown in FIG. 9, the static eliminator 800 in this embodiment includes an expansion / contraction unit 810 that enables the static eliminator 200 to move up and down in addition to the static eliminator 200 in the first embodiment.

  The telescopic unit 810 includes a hollow cylindrical first pipe 811, a hollow cylindrical pipe, a second pipe 812 having an outer diameter equal to the inner diameter of the first pipe 811, and a hollow cylindrical pipe. And a third pipe 813 having an inner diameter equal to the outer diameter of the second pipe 812.

  The inner diameter of the third pipe 813 is selected to be equal to the outer diameter of the pipe 210 of the static eliminator 200.

  That is, the first pipe 811, the second pipe 812, the third pipe 813, and the pipe 210 have a “nesting type” structure, and are mutually stretchable.

  Screws 814, 815, and 816 are respectively attached in the horizontal direction near the lower end of the first pipe 811 and near the upper end and the lower end of the third pipe 813. By tightening the screw 814, the first pipe 811 is connected to the second pipe. The third pipe 813 can be fixed to the second pipe 812 by tightening the screw 815, and the third pipe 813 can be fixed to the pipe 210 by tightening the screw 816. It has become.

  That is, the total length of the expansion / contraction unit 810 can be adjusted to a desired length by the screws 814, 815, and 816.

  Similarly to the self-discharge type static eliminator 700 according to the sixth embodiment, the static eliminator 800 according to the present embodiment also has a position of the self-discharge electrode 220 formed at the tip of the pipe 210, that is, a position where corona discharge is generated. Can be moved up and down inside the sight glass 1, and corona discharge can be generated at a position where the electric field strength is greatest inside the sight glass 1.

(Eighth embodiment)
FIG. 10 is a perspective view of a static eliminator 900 used in the pellet supply apparatus according to the eighth embodiment of the present invention.

  The pellet supply apparatus according to the present embodiment has the same structure as the pellet supply apparatus 100 according to the first embodiment except that a static eliminator 900 is used instead of the static eliminator 200.

  As illustrated in FIG. 10, the static eliminator 900 according to the present embodiment additionally includes an insulator cover 910 as compared with the self-discharge type static eliminator 700 according to the sixth embodiment.

  The insulator cover 910 is made of an insulating material and has a diameter sufficiently larger than the diameter of the pipe 510 or the electrode support 713. As shown in FIG. 10, the insulator cover 910 is disposed so as to be concentric with the pipe 510 or the electrode support 713 without contacting the pipe 510 or the electrode support 713.

  When the self-discharge electrode is placed in the charged particle group, the electric field is concentrated on the self-discharge electrode, causing a problem that the fine charged particle group adheres due to electrostatic attraction.

  Further, if insulating charged particles adhere to the tip of the self-discharge electrode, the electric field at the tip of the self-discharge electrode is weakened, and self-discharge itself does not occur, which may cause a reduction in the charge removal effect.

  By providing the insulator cover 910, it becomes possible to prevent the charged particles having an electrostatic charge from adhering to the extension body 520 functioning as a self-discharge electrode to some extent, and the self-discharge function of the extension body 520 is reduced. It is possible to prevent.

  In addition, since the electrostatic force of the charged particle group adhering to the outer wall of the insulator cover 910 becomes weaker as the diameter of the insulator cover 910 is larger, the effect of preventing the self-discharge function of the extension body 520 from being lowered is increased. However, if the diameter of the insulator cover 910 becomes too large, the charged particle group can easily enter the inside of the insulator cover 910, so it is necessary to select an appropriate diameter.

  In the static eliminator 900 in this embodiment, the insulator cover 910 has a cylindrical shape, but the shape of the insulator cover 910 is not limited to a cylindrical shape. As long as the charged particles can be prevented from adhering to the pipe 510 or the electrode support 713, the insulator cover 910 can have any shape.

  Further, instead of the insulator cover 910, an insulating layer covering the outer surface of the pipe 510 or the electrode support 713 can be used. Such an insulating layer can be made of, for example, a resin.

  The insulator cover 910 is preferably made of a material that charges the charged particle group in contact with the insulator cover 910 to a reverse polarity.

  When the insulator cover 910 is made of such a material, the charge amount of the charged particle group can be reduced.

FIG. 1 is a cross-sectional view of a pellet supply apparatus according to a first embodiment of the present invention. FIG. 2 is a perspective view of a static eliminator used in the pellet supply apparatus according to the first embodiment of the present invention. FIG. 3 is a perspective view of a static eliminator used in the pellet supply apparatus according to the second embodiment of the present invention. FIG. 4 is a perspective view of a static eliminator used in the pellet supply apparatus according to the third embodiment of the present invention. FIG. 5 is a bottom view of the static eliminator of FIG. 4 when viewed from the direction A of FIG. FIG. 6 is a perspective view of a static eliminator used in the pellet supply apparatus according to the fourth embodiment of the present invention. FIG. 7 is a perspective view of a static eliminator used in the pellet supply apparatus according to the fifth embodiment of the present invention. FIG. 8 is a perspective view of a static eliminator used in the pellet supply apparatus according to the sixth embodiment of the present invention. FIG. 9 is a perspective view of a static eliminator used in the pellet supply apparatus according to the seventh embodiment of the present invention. FIG. 10 is a perspective view of a static eliminator used in the pellet supply apparatus according to the eighth embodiment of the present invention. FIG. 11 is a sectional view of a conventional pellet feeder.

Explanation of symbols

100 Pellet Supply Device 200 According to First Embodiment of the Present Invention Charger 210 Used in the Pellet Supply Device According to the First Embodiment of the Present Invention 210 Pipe 211 Through-hole 212 Fixing Tool 213 Bellows Hose 220 Self-Discharge Electrode 230 Air flow generating means 300 Static eliminator 310 used in the pellet supply apparatus according to the second embodiment of the present invention Pipe 311 Through-hole 320 Self-discharge electrode 400 Used in the pellet supply apparatus according to the third embodiment of the present invention. Static eliminator 410 Pipe 411 Through-hole 420 Self-discharge electrode 500 Static eliminator 510 used in pellet supply apparatus according to the fourth embodiment of the present invention Pipe 511 Through-hole 520 Extension body 600 In the fifth embodiment of the present invention The static eliminator 610 used in the pellet supply apparatus, the pipe 611, the through hole 620, and the extension 700. Static eliminator 710 used in pellet supply apparatus according to sixth embodiment Fixing means 800 Static eliminator 810 used in pellet supply apparatus according to seventh embodiment of the present invention Telescopic unit 900 Eighth implementation of the present invention Static eliminator 910 insulator cover used in pellet supply apparatus according to embodiment

Claims (15)

A hopper for storing pellets;
Sight glass connecting the hopper and the molding device;
A static eliminator for neutralizing the inside of the sight glass;
A pellet feeder comprising:
The static eliminator is
A pipe in which at least one through hole is formed in the axial direction, one end of which is located in the sight glass; and
Made of a conductive material, the same number of self-discharge electrodes as the through holes,
Consists of
The pellet supply apparatus, wherein the self-discharge electrode is attached to the pipe so that a tip of the self-discharge electrode overlaps the through hole corresponding to the self-discharge electrode in the axial direction of the pipe. The self-discharge electrode is attached to the pipe so that a tip of the self-discharge electrode overlaps a center of the through hole corresponding to the self-discharge electrode in an axial direction of the pipe. 2. The pellet supply apparatus according to 1. A hopper for storing pellets;
Sight glass connecting the hopper and the molding device;
A static eliminator for neutralizing the inside of the sight glass;
A pellet feeder comprising:
The static eliminator is
A pipe in which at least one through hole is formed in the axial direction, one end of which is located in the sight glass; and
A self-discharge electrode made of a conductive material;
Consists of
The self-discharge electrode has the same number of tip portions as the through-holes,
The self-discharge electrode is a pellet supply device attached to the pipe such that each of the tip portions overlaps the corresponding through-hole in the axial direction of the pipe. The said self-discharge electrode is attached to the said pipe so that each of the said front-end | tip parts may overlap with the center of the said corresponding through-hole in the axial direction of the said pipe. Pellet feeder. The pellet supply apparatus according to any one of claims 1 to 4, wherein the self-discharge electrode is grounded or an alternating bias voltage is applied to the self-discharge electrode. A hopper for storing pellets;
Sight glass connecting the hopper and the molding device;
A static eliminator for neutralizing the inside of the sight glass;
A pellet feeder comprising:
The static eliminator is
A pipe in which at least one through-hole is formed in the axial direction, one end of which is a pipe located in the sight glass,
The pipe is made of a conductive material,
A pointed extension is formed at one end of the pipe, and the extension is bent so that the tip of the extension overlaps the through hole corresponding to the extension in the axial direction of the pipe. . The pellet supply according to claim 6, wherein the extension body is bent so that a tip end of the extension body overlaps a center of the through hole corresponding to the extension body in an axial direction of the pipe. apparatus. The one end of the pipe has a surface inclined with respect to the central axis of the pipe, and the extension body is formed at a position on the most distal end side of the inclined surface. 8. The pellet supply apparatus according to 7. The pellet supply apparatus according to any one of claims 6 to 8, wherein the pipe and the extension body are integrated. The pellet supply apparatus according to any one of claims 6 to 9, wherein the pipe is a metal hollow pipe having an outer diameter of 3 mm or less. The pellet supply apparatus according to any one of claims 6 to 9, wherein the pipe is grounded or an AC bias voltage is applied to the pipe. The pellet supply apparatus according to any one of claims 1 to 11 , further comprising an insulating layer covering an outer surface of the pipe. The pellet supply apparatus according to any one of claims 1 to 12, wherein the pipe has a structure that can expand and contract in an axial direction thereof. The pellet supply apparatus according to any one of claims 1 to 13, further comprising an insulator cover that is separated from the pipe and covers the periphery of the pipe and is made of an insulating material. The pellet supply apparatus according to claim 14, wherein the insulator cover is made of a material that charges a charged body in contact with the insulator cover with a reverse polarity.

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