JP2008189841A - Method for regenerating sponge blast medium and device therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for reclaiming a sponge blast medium, capable of regenerating the sponge blast medium decreased in size by half so as to be almost new article state. <P>SOLUTION: Sponge blast mediums 12A of unreusable size are thrown in a container 14. Then, a rotating mechanism 26 and an elevating mechanism 28 are regulated by a driving regulating part 34 and agitator blades 24, 24 are rotated and moved up and down. And when operating the agitator blades 24, 24, a predetermined amount of a binder 16 and/or an abrasive 30 are added/supplied from an upper end opening 20A of a hollow rotation shaft 20 through a binder-adding tube 74 and/or an abrasive-adding tube 86. Then, by rotating the agitator blades 24, 24 for a predetermined time, small-sized sponge blast mediums 12A, 12A, ... are bonded each other by bonding action of the binder 16. Then, when regenerated to be almost the size of new sponge blast medium 12B, the agitator blades 24, 24 are stopped. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method and apparatus for regenerating a sponge blast medium, and more particularly to a method and apparatus for regenerating a sponge blast medium in which an abrasive is fixed to a sponge piece and cannot be reused.

  When repainting the painted wall surface, a blasting operation is performed as a preliminary work to grind the coating film on the wall surface and roughen the painted surface to adjust the substrate. The blasting medium used at this time is generally sand or steel as in Patent Document 1, but recently, the abrasive is fixed in a porous elastic body (foamed polyurethane pellet) as in Patent Document 2. A so-called sponge blasting method using a sponge piece blasting medium has attracted attention from the viewpoint of improving the working environment.

  According to this sponge blasting method, when the sponge blasting medium sprayed with high-speed air from the nozzle collides with the painted surface, the blasting medium becomes flat and the mixed abrasive material directly collides with the painted surface at high speed. Similar to the construction method, the coating film can be ground and removed. Further, since the generated dust is taken into the sponge piece, there is an advantage that the working environment is improved.

On the other hand, the applicant of the present application has proposed a technique for judging the service life of a sponge blast medium in Patent Document 3. In this service life judgment method, during operation of the sponge blast injection device, a part of the sponge blast medium subjected to grinding is collected in a particle size measuring machine, and this particle size measuring machine collects the abrasive in the sponge blast medium. Measure the particle size and create a particle size distribution. Then, when the peak value of the particle size distribution after being used a plurality of times becomes smaller than the use limit diameter, it is determined that the sponge blast medium of the rod cannot be reused.
JP 2005-314732 A JP 2006-247770 A JP 2006-224260 A

  By the way, the sponge blast medium once sprayed by the sponge blast spray device is partially broken and powdery dust is generated. The original (new) sponge blasting medium is about 7-8 mm in diameter. When the blasting operation is repeated a plurality of times, the size of the sponge blast medium gradually decreases and the abrasive such as alumina fixed to the sponge piece is peeled off from the sponge piece. When the size of the sponge blasting medium and the number of abrasives are halved, the blasting function is greatly reduced after that, making it impossible to reuse. That is, with such a sponge blasting medium, it is not possible to obtain the prescribed value of the unevenness of the processing target surface even if blasting is continued.

  Since the sponge blast medium is expensive, it is not economical to discard the half-sized sponge blast medium as it is. For this reason, it has been desired to reuse a sponge blasting medium having a half size by recycling it.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a method and apparatus for regenerating a sponge blast medium for regenerating a sponge blast medium having a half size in a substantially new state. To do.

  In order to achieve the above object, the method invention according to claim 1 puts a sponge blast medium having a size smaller than a predetermined size into a container and adds a predetermined amount of a binder made of an aqueous polyurethane emulsion to the sponge blast medium. Then, the mixture is regenerated into a sponge blast medium of the predetermined size by stirring.

  In order to achieve the above object, a device invention according to claim 5 is a container in which a sponge blast medium having a size smaller than a predetermined size is charged, a hollow rotating shaft inserted and disposed in the container, and the hollow A stirring blade attached to a rotating shaft and having a supply hole communicating with a hollow portion of the hollow rotating shaft, a rotating mechanism for rotating the stirring blade in the container by rotating the hollow rotating shaft, and the rotation A mechanism, the agitating blade, and an elevating mechanism for integrally raising and lowering the hollow rotating shaft, and a polyurethane aqueous emulsion binder and / or an abrasive material for the sponge blast medium are added / supplied from the upper end opening end of the hollow rotating shaft. Supply mechanism, drive control means for driving and controlling the rotation mechanism and the lifting mechanism, and addition of the binder and / or the abrasive by the supply mechanism. It is characterized by comprising a supply amount control means for controlling the amount / feed amount.

  According to the first and fifth aspects of the present invention, a sponge blast medium having a non-reusable size (a size smaller than a predetermined size) is put into a container. This input amount (mass) is measured in advance. Thereafter, the rotation mechanism and the lifting mechanism are controlled by the drive control means, and the stirring blade is rotated and moved up and down. Then, during the operation of the stirring blade, the supply amount control means controls the supply mechanism, and a predetermined amount of binder and / or sponge blast medium abrasive is added / supplied from the upper end opening end of the hollow rotating shaft. Accordingly, the binder and / or the abrasive is added / supplied to the sponge blast medium from the supply hole of the stirring blade. After that, when the stirring blades are driven for a predetermined time, the small-sized sponge blasting media are connected to each other by the binding action of the binder, and the stirring blades are driven when the sponge blasting media is regenerated to a substantially new size. Stop. As a result, according to the present invention, the sponge blast medium having a half size can be regenerated to a substantially new state.

  Claim 5 defines the supply of the abrasive. In this case, the supply amount of the abrasive is also defined based on the mass of the sponge blast medium put into the container, as is the addition amount of the binder, and the number of abrasives contained in the regenerated sponge blast medium is approximately the same. It is set to be substantially the same as a new sponge blast medium. This is because the number of abrasives is also halved in the same manner as the sponge pieces whose size is halved, and therefore the supply amount of the abrasives can be easily calculated from the mass of the sponge blasting medium to be charged.

  The binder is a binder based on MSDS specifications manufactured under certain conditions, and is a tro-taste alkaline polyurethane aqueous emulsion (foamed urethane rubber binder) containing 25-40% polyurethane resin. The specific gravity is about 1.1.

  The method invention according to claim 2 is characterized in that, in claim 1, the amount of the binder added is 1 to 10% (w / w) with respect to the mass of the sponge blast medium before regeneration. .

  The apparatus invention according to claim 6 is the apparatus invention according to claim 5, wherein the amount of the binder added by the supply mechanism is 1 to 10% (w / w) of the mass of the sponge blast medium put into the container. It is characterized by being set.

  According to the invention described in claims 2 and 6, the amount of the binder added is 1 to 10% (w / w) of the mass of the sponge blasting medium (sponge piece + abrasive) before being put into the container. It is preferable to do.

  The hardness (HsC) of the sponge piece of a new sponge blast medium is about 10 to 30, and the sponge blast medium having this hardness exhibits the initial blast performance. That is, increasing the hardness of the sponge piece of the sponge blast medium that has become non-reusable up to the above-mentioned hardness is an indication of the regeneration of the sponge blast medium. The hardness (HsC) of the sponge piece is a hardness in accordance with “Method for testing physical properties of polyurethane elastomer formed product” defined in JIS K7312. In this test method, there are four types A to D according to the hardness measurement object, but in the case of a sponge, it is a C type.

  By the way, the hardness of the sponge piece is proportional to the ratio (%) of the binder mass to the mass of the sponge blast medium, and the hardness of the sponge piece increases as the binder mass increases, that is, as the amount of binder added increases. There is a tendency. Based on this tendency, when the binder mass exceeds 10% (w / w) of the mass of the sponge blast medium, the hardness of the sponge piece of a new sponge blast medium is exceeded. Since the hardness of the sponge piece and the adhesiveness of the sponge piece that wipes the blasting surface are inversely proportional to each other, if the sponge piece becomes too hard, the adhesiveness is reduced, and it becomes difficult for the sponge piece to absorb dust during blasting. . On the other hand, if the binder mass is less than 1% (w / w), a sufficient binding force cannot be obtained, so that the broken sponge piece does not return to its original size and the function cannot be satisfactorily achieved. Therefore, the binder addition amount is preferably 1 to 10% (w / w) of the mass of the sponge blasting medium before being put into the container.

  In addition, the regenerated product of the sponge blasting medium regenerated by adding the binder is passed through a loosening machine and a sieving machine, and if the regenerated product has a new size of about 7 to 8 mm and is 90% or more, the regeneration may be completed. it can.

  Further, when the binder addition amount exceeds 10% (w / w), there is a track record that the reproduction size becomes too larger than the new size, and the sponge blast medium is bridged in the injector. From this point of view, the binder addition amount is preferably 1 to 10% (w / w) of the mass of the sponge blast medium.

  Regarding the addition of the binder, it is preferable to measure the addition amount in advance with a flow meter and to give the regenerator an automatic stop function in order to prevent over-addition.

  On the other hand, in the sponge blast medium reproducing apparatus, unlike the stirring in the beaker, the binder is added to the sponge blast medium having a predetermined weight (for example, about 10 kg) and stirred, and thus the following problems occur. That is, it is difficult to stir evenly. Further, when a large load acts on the stirring blade during stirring, the essential sponge blast medium is crushed. Therefore, in order to solve such a problem, the solution means is described in the following dependent claims.

  According to a third aspect of the present invention, in the first and second aspects, the stirring blade that is stirred is moved up and down in the container while rotating, and the amount of the binder added is determined by the stirring blade in the container. It is characterized by being added in such a manner that it is often used when it descends and decreases when it rises.

  The invention of claim 7 is the apparatus invention according to claim 5, wherein the drive control means drives and controls the elevating mechanism so that the agitating blades move up and down in the container while rotating. The supply amount control means controls the addition amount so that the binder addition amount is increased when the stirring blade is lowered in the vessel and the binder addition amount is decreased when the stirring blade is raised.

  According to the third and seventh aspects of the invention, it is preferable that the stirring blade is moved up and down at a low speed while rotating the stirring blade. For example, it is set in advance so that the whole amount of the binder is added during two reciprocating ascent and descent operations, and then rotated and moved up and down 7 to 8 times to reciprocate the sponge blast medium put into the container. The binder is added substantially evenly. Further, it is preferable to control the addition amount according to the rising and lowering positions of the stirring blade so that the binder addition amount is increased when the stirring blade is lowered and the binder addition amount is decreased when the stirring blade is raised. Thereby, a binder is more uniformly added with respect to the sponge blasting medium thrown into the container.

  According to a fourth aspect of the present invention, in the first, second, and third aspects, the stirring blade is characterized in that the number of rotations is small when descending in the container and the number of revolutions is large when rising. Yes.

  According to an eighth aspect of the present invention, in the fifth, sixth, and seventh aspects, the drive control means is configured such that the rotational speed is small when the stirring blade is lowered in the container, and the rotational speed is large when the stirring blade is raised. The rotation mechanism is controlled so as to be.

  According to the fourth and eighth aspects of the present invention, it is preferable that the rotation speed of the stirring blade is reduced when the stirring blade is lowered and the rotation speed is increased when the stirring blade is raised. Thereby, it is possible to prevent the sponge blast medium from being crushed due to an excessive load applied to the sponge blast medium.

  In the case of regenerating a sponge blast medium in which the abrasive is peeled off from the sponge, only the abrasive can be supplied from the upper part through a separate pipe.

  As another example of the sponge blast medium regenerating apparatus, a spiral stirring blade is provided on the inner wall surface, the sponge blast medium is put into the drum, and the binder and / or abrasive is supplied from the supply pipe while rotating the drum. And the sponge blast medium may be reproduced. If the drum is tilted after reproduction, the reproduced sponge blast medium can be discharged from the drum.

  According to the method and apparatus for regenerating a sponge blast medium according to the present invention, a sponge blast medium having a size smaller than a predetermined size is put into a container, and a predetermined amount of a polyurethane aqueous emulsion binder is added to the sponge blast medium. Since stirring is performed with the stirring blade, the sponge blast medium having the predetermined size can be regenerated. Thereby, the sponge blasting medium whose size has been reduced by half can be reproduced in a substantially new state.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a method and apparatus for reproducing a sponge blast medium according to the present invention will be described below in detail with reference to the accompanying drawings.

  FIG. 1 is a conceptual diagram of a method for reproducing a sponge blast medium according to an embodiment, and FIG. 2 is a side view of a reproducing apparatus 10 for reproducing the sponge blast medium.

  First, the conceptual diagram of the reproduction method shown in FIG. 1 will be described. A new sponge blast medium (new medium (foamed urethane pallet)) 12 has a diameter of about 7 to 8 mm. When used repeatedly for blasting, its diameter is reduced to about 3 to 4 mm and becomes functionally non-reusable. This non-reusable half-size sponge blast medium 12A is put into a container 14, a predetermined amount of binder 16 is added, and the mixture is stirred by the stirring means 18, thereby being regenerated into a sponge blast medium 12B of almost new size. . The sponge blast medium 12 is a medium in which a large number of granular abrasives such as alumina, steel, and sand are fixed in a porous elastic body (foamed polyurethane pellets). The binder 16 is a binder based on the MSDS (Material Safety Data Sheet) specification manufactured under a certain condition, and is an alkaline polyurethane aqueous emulsion (foamed urethane rubber binder) having a troy taste. It contains 25-40% resin and has a specific gravity of about 1.1. By adding the binder 16, the sponge blast media 12A, 12A... About half are combined and regenerated into a sponge blast media 12B having a substantially new size.

  Next, the reproducing apparatus 10 shown in FIG. 2 will be described with reference to the perspective view of FIG. 3 and the main structure diagram of FIG.

  The reproducing apparatus 10 shown in these drawings includes a cylindrical container 14 into which a sponge blast medium 12A is charged, a hollow rotating shaft 20 that is inserted along the central axis 14A of the container 14, and a lower end portion of the hollow rotating shaft 20. Agitating blades 24, 24 (supply holes are not shown in one agitating blade 24), which are attached and communicated with the hollow portion of the hollow rotating shaft 20, are formed, and the hollow rotating shaft 20 is rotated. Accordingly, the rotating mechanism 26 that rotates the stirring blades 24 and 24 in the container 14, the lifting mechanism 28 that integrally moves the rotating mechanism 26, the stirring blades 24 and 24, and the hollow rotating shaft 20, and the upper end opening of the hollow rotating shaft 20. A supply mechanism 32 for adding / supplying the binder 16 and / or the abrasive 30 of the sponge blast medium 12 from the end 20A, a drive control unit 34 for driving and controlling the rotation mechanism 26 and the lifting mechanism 28; And a feed mechanism 32 by a binder 16 and / or the supply amount control unit 36 for controlling the addition amount / feed amount of the grinding member 30.

  As shown in FIG. 2, the container 14 is detachably attached to a base 38 by a metal fitting 40. In addition, two elevating mechanisms 28 and 28 are erected on the base 38 on both sides of the container 14.

  Each lifting mechanism 28 is constituted by a feed screw device, and is constituted by a servo motor 42, a screw rod 44 (see FIG. 4), a rod 46, and a guide cylinder 48. The screw rod 44 is connected to the output shaft of the servo motor 42 and is driven to rotate about the vertical axis by the power of the servo motor 42. Further, the rod 46 is formed in a cylindrical shape, and a screw rod 44 is screwed into a threaded portion (not shown) threaded on the inner peripheral surface of the rod 46 as shown in FIG. Further, the rod 46 is supported by a guide cylinder 48 erected on the casing 50 of the servo motor 42 so as to be linearly movable in the vertical direction. Therefore, when the screw rod 44 is driven forward / reversely by the servo motor 42, the rod 46 is moved up and down by the feeding action of the screw rod 44. The raising / lowering amount of the rod 46 is controlled by a drive control unit 34 that feedback-controls the servo motor 42, and the drive control unit 34 cooperatively controls the two servo motors 42 and 42. Therefore, the two rods 46 and 46 are simultaneously moved up and down by the same amount in the same direction at the same speed. The lifting mechanism 28 may be another linear feed mechanism such as an air cylinder or a hydraulic cylinder as long as it can control the amount of movement of the rod 46.

  As shown in FIG. 2, a single beam 52 is stretched horizontally and fixed to the upper ends of the rods 46, 46, and an opening 52A is formed at the center of the beam 52 as shown in FIG. It is formed. The hollow rotary shaft 20 is inserted into the opening 52A. The hollow rotary shaft 20 is supported by the bearing 54 in the radial direction at the opening 52A, and is supported by the thrust in the thrust direction by the bearing 56 so as to be rotatable. Has been placed. Further, as shown in FIG. 2, an L-shaped support 58 is erected below the beam 52, and the middle part of the hollow rotary shaft 20 rotates on the slide bearing 60 shown in FIG. 4 provided at the upper end of the support 58. It is supported freely. With this two-point rotation support structure, the hollow rotary shaft 20 is rotated around the central axis 14A of the container 14 without tilting.

  The rotation mechanism 26 is disposed close to the opening 52A of the beam 52, and mainly includes a servo motor 62 whose rotation speed is controlled by the drive control unit 34. This servo motor 62 is fixed to the beam 52. A gear 66 fixed to the hollow rotary shaft 20 is engaged with a gear 64 fixed to the output shaft 63. Therefore, when the servo motor 62 is driven, the driving force is transmitted from the gear 64 to the hollow rotary shaft 20 via the gear 66, and the hollow rotary shaft 20 is rotated. As a result, the stirring blades 24 and 24 are rotated in the container 14. Further, the rotation direction of the stirring blades 24, 24 is set to a direction with the formation surface of the supply holes 22, 22 ... as the back surface so that the sponge blast medium 12A does not enter the supply holes 22, 22 .... Although the inclination angle of the stirring blade 24 is arbitrary, the binder 16 and the abrasive 30 are added / supplied between the back surface of the stirring blade 24 and the sponge blast medium 12A during the rotating operation of the stirring blade 24. The angle at which the gap is generated is set.

  The supply mechanism 32 for adding / supplying the binder 16 and / or the abrasive 30 includes a container 68 in which the binder 16 is stored, a flow meter 70 for measuring the addition amount (mass) of the binder 16 based on the flow rate of the binder 16, and an electromagnetic valve. 72, binder addition tube 74, hopper 76 in which abrasive 30 is stored, electromagnetic valve 78, buffer container 80 in which abrasive 30 is temporarily stored, and mass for measuring the mass of abrasive 30 stored in buffer container 80 It comprises a sensor 82, an electromagnetic valve 84, and an abrasive supply tube 86. The binder addition tube 74 and the abrasive supply tube 86 are inserted to the lower end portion of the hollow rotary shaft 20 in a free state with respect to the hollow rotary shaft 20.

  According to the supply mechanism 32, when the electromagnetic valve 72 is opened, the binder 16 in the container 68 is supplied to the hollow rotary shaft 20 via the binder addition tube 74, whereby the binder 16 is fed to the stirring blade 24. It is added into the container 14 from the supply holes 22, 22. The addition amount of the binder 16 is measured by the flow meter 70, and the information is output to the supply amount control unit 36.

  When the electromagnetic valve 78 is opened, the abrasive 30 in the hopper 76 is stored in the buffer container 80, and when the specified amount of material is stored, the electromagnetic valve 78 is closed and the electromagnetic valve 84 is opened. The Thus, the abrasive 30 is supplied to the hollow rotary shaft 20 via the abrasive supply tube 86 and supplied into the container 14 from the supply holes 22 of the stirring blade 24. The mass of the abrasive 30 stored in the buffer container 80 is measured by the mass sensor 82, and the information is output to the supply amount control unit 36. The electromagnetic valve 84 is controlled by the supply amount control unit 36 so as to be closed when the abrasive 30 in the buffer container 80 becomes empty. Further, the abrasive 30 may be supplied using another pipe. Furthermore, the addition amount per hour of the binder 16 is set by a flow restriction restriction (not shown) so that the binder 16 does not clog the supply hole 22.

  The supply amount control unit 36 controls the opening and closing of the electromagnetic valve 72 and / or the electromagnetic valve 78 and the electromagnetic valve 84 based on the mass of the sponge blast medium 12A input into the container 14 that is input in advance. That is, when the mass of the sponge blast medium 12 </ b> A charged in the container 14 is input from another input unit, the supply amount control unit 36 calculates the addition amount (mass) of the binder 16. Then, the electromagnetic valve 72 is opened, and the addition amount (mass) of the binder 16 added at that time is calculated based on the information from the flow sensor 70, and the calculated addition amount (mass) is reached. Then, the electromagnetic valve 72 is closed. Thereby, an amount of the binder 16 corresponding to the mass of the sponge blast medium 12A is added to the sponge blast medium 12A.

  Similarly, the supply amount control unit 36 calculates the supply amount (mass) of the abrasive 30 based on the mass of the sponge blast medium 12 </ b> A charged into the container 14. Then, the electromagnetic valve 78 is opened, and the supply amount (mass) of the abrasive 30 stored in the buffer container 80 at that time is calculated based on information from the mass sensor 82. When the calculated supply amount (mass) is reached, the electromagnetic valve 78 is closed and the electromagnetic valve 84 is opened. Thereby, an amount of abrasive 30 corresponding to the mass of the sponge blast medium 12A is supplied to the sponge blast medium 12A.

  Next, the operation of the reproducing apparatus 10 configured as described above will be described.

  First, a sponge blast medium 12A having a size that cannot be reused is put into the container 14. This input amount (mass: 20 kg, for example) is measured in advance. Thereafter, the drive control unit 34 controls the rotation mechanism 26 and the lifting mechanism 28 to rotate the stirring blades 24 and 24 and move them up and down. During the operation of the stirring blades 24, 24, the supply amount control unit 36 controls the supply mechanism 32, and the binder 16 and / or the abrasive 30 is transferred from the upper end opening end 20 </ b> A of the hollow rotary shaft 20 to the binder addition tube 74. Then, a predetermined amount is added / supplied through the abrasive supply tube 86. Thereby, the binder 16 and / or the abrasive 30 are added / supplied to the sponge blasting medium 12A from the supply holes 22, 22... Of the stirring blades 24, 24. Thereafter, when the agitating blades 24, 24 are driven for a predetermined time, the small-sized sponge blasting media 12A, 12A,... Are joined together by the binding action of the binder 16, and are regenerated to the size of a substantially new sponge blasting media 12B. At that time, the driving of the stirring blades 24, 24 is stopped. Thereby, according to the reproducing | regenerating apparatus 10 of embodiment, 12 A of sponge blast media which reduced the size can be reproduced | regenerated to a substantially new size.

  The regenerated sponge blasting medium 12B can be recovered from the upper opening of the container 14, but as shown in FIGS. 2 and 3, the bottom lid 15 of the container 14 is removed, and the base 38 of the container 14 is removed. It can be taken out of the container 14 through an outlet 38A formed immediately below.

  Moreover, the abrasive 30 can also be supplied simultaneously. In this case, the supply amount of the abrasive 30 is set on the basis of the mass of the sponge blast medium 12A charged into the container 14 in the same manner as the addition amount of the binder 16, and the abrasive contained in the regenerated sponge blast medium 12B. The number of 30 is set to be substantially the same as that of a substantially new sponge blast medium 12. This is because the number of abrasives 30 is also halved in the same manner as the sponge pieces whose sizes are halved, and therefore the supply amount of the abrasives 30 can be easily calculated from the mass of the sponge blast medium 12A to be charged.

  The addition amount of the binder 16 is preferably 1 to 10% (w / w) with respect to the mass of the sponge blast medium 12A before regeneration.

  The hardness (HsC) of the sponge piece of the new sponge blast medium 12A is about 10 to 30, and the sponge blast medium having this hardness exhibits the initial blast performance. That is, increasing the hardness of the sponge piece of the sponge blast medium 12A, which has become unusable, to the above-mentioned hardness is an indication of the regeneration of the sponge blast medium. The hardness (HsC) of the sponge piece is a hardness in accordance with “Method for testing physical properties of polyurethane elastomer formed product” defined in JIS K7312. In this test method, there are four types A to D according to the hardness measurement object, but in the case of a sponge, it is a C type.

  By the way, as shown in the graph of FIG. 5, the hardness (HsC) of the sponge piece is proportional to the ratio (%) of the binder mass to the mass of the sponge blast medium 12A, and as the binder mass increases, that is, the binder As the added amount increases, the hardness of the sponge piece tends to increase. Based on this tendency, if the binder mass exceeds 10% (w / w) of the mass of the sponge blast medium 12A, the hardness of the sponge piece of the new sponge blast medium 12 will be exceeded. Since the hardness of the sponge piece and the adhesiveness of the sponge piece that wipes the blasting surface are inversely proportional to each other, if the sponge piece becomes too hard, the adhesiveness is reduced, and it becomes difficult for the sponge piece to absorb dust during blasting. . On the other hand, if the binder mass is less than 1% (w / w), a sufficient binding force cannot be obtained, so that the broken sponge piece does not return to its original size and the function cannot be satisfactorily achieved. Therefore, the binder mass (addition amount) is preferably 1 to 10% (w / w) of the mass of the sponge blasting medium 12A before being put into the container 14.

  Sponge blasting medium 12B added with a specified amount of binder 16 is applied to a loosening machine and a sieve, and the reproduction is completed when 90% or more of the new product is about 7-8 mm, which is a new size. You can also.

  Further, when the binder mass exceeds 10% (w / w), the reproduction size becomes too large compared to the new size, and there is a track record that a bridge is generated in the sponge blast medium in the injector. From this point of view, the binder mass (addition amount) is preferably 1 to 10% (w / w) of the mass of the sponge blast medium 12A.

  On the other hand, in the reproducing apparatus 10, since the binder 16 is added to the sponge blast medium 12A having a predetermined weight (for example, about 10 kg) and stirred, unlike the stirring in the beaker, the following problem occurs. That is, it is difficult to stir evenly. Further, when a large load acts on the stirring blade 24 during stirring, the essential sponge blast medium is crushed. Therefore, in order to solve such a problem, the solution means will be described below.

  That is, the drive control unit 34 drives and controls the elevating mechanism 28 so that the stirring blades 24 and 24 are moved up and down in the container 14 while the stirring blades 24 and 24 are rotating. It is preferable to control the addition amount of the binder 16 so that the binder addition amount increases as it descends in the container 14 and decreases as it rises. For example, with the stirring blades 24, 24 positioned at the bottom of the container 14, the sponge blasting medium 12A before regeneration is put into the container 14, and then the stirring blades 24, 24 are rotated, and the reciprocation is performed twice. It is set in advance so that the entire amount of the binder 16 is added during the lowering operation, and after that, it is rotated and reciprocated up and down 7 to 8 times. As a result, the binder 16 is added substantially evenly to the sponge blast medium 12 </ b> A charged in the container 14. Further, by controlling the addition amount in proportion to the rising and lowering positions of the stirring blades 24 and 24 so that the binder addition amount increases as the stirring blades 24 and 24 descend, and the binder addition amount decreases as the stirring blades 24 and 24 rise. The binder 16 can be more evenly added to the sponge blast medium 12A charged in the container 14.

  Further, the drive control unit 34 can control the rotation mechanism 26 so that the rotation speed decreases as the stirring blades 24 and 24 descend within the container 14 within a range of 30 rpm, for example, and increases as the speed increases. preferable. Thereby, it is possible to prevent the sponge blast medium 12A from being crushed due to an unnecessary load on the sponge blast medium 12A. The drive control unit 34 measures the current of the servo motor 62 when the stirring blades rotate, and automatically controls the rotation speed so as to operate at a substantially constant current.

  FIG. 6 is a structural view showing another embodiment of the reproducing apparatus 90 for a sponge blast medium.

  The regenerator 90 shown in the figure is provided with a spiral stirring blade 92 on the inner wall surface, the sponge blast medium 12A is introduced into the drum 94, and the drum 94 and the binder 16 and In other words, it is an apparatus that inputs the abrasive 30 and regenerates the sponge blast medium.

  A shaft 100 protrudes from the closed end 94 </ b> A of the drum 94 along the shaft core 95 of the drum 94, and this shaft 100 is rotatably supported by a bearing 104 installed on the tilt table 102. Further, a ring-shaped flange 106 is fixed to the outer peripheral portion in the vicinity of the opening end 94 </ b> B of the drum 94, and a roller 108 is pressed against the flange 106. The roller 108 is fixed to the output shaft 97 of the motor 96 installed on the tilt base 102. Therefore, when the motor 96 is driven, the power is transmitted from the roller 108 to the drum 94 via the flange 106. Therefore, the shaft core 95 of the drum 94 is moved with the drum 94 inclined at a predetermined angle as shown in FIG. Rotated to the center. As a result, the entire sponge blast medium 12 </ b> A charged into the drum 94 is efficiently stirred by the rotating stirring blade 92.

  The supply pipe 98 is configured to be freely inserted into and removed from the drum 94 along the shaft core 95 of the drum 94 from the opening end 94B of the drum 94, and when the binder 16 and / or the abrasive 30 is charged, the drum 94 as shown in FIG. When the charging is finished, it is taken out of the drum 94. The supply / removal operation of the supply pipe 98 may be automatically performed using a drive mechanism, but may be performed manually. Of course, the addition / supply amount of the binder 16 and / or the abrasive 30 is based on the mass of the sponge blast medium 12 </ b> A charged into the drum 94.

  The front end (right end in FIG. 6) of the tilt base 102 is swingably supported by the base 112 via the hinge shaft 110, and the rear end (left end in FIG. 6) is the rod 116 of the hydraulic cylinder 114. The hinge shaft 118 is supported so as to be swingable. The hydraulic cylinder 114 is swingably supported by the base 112 via the hinge shaft 120. The swing directions by the hinge shafts 110, 118, and 120 are the same.

  According to the reproducing apparatus 90 having such a configuration, first, the sponge blast medium 12 </ b> A is put into the drum 94. This input amount is set to a level L indicated by a one-dot chain line in FIG. Thereafter, while the drum 94 is rotated by the motor 96, the binder 16 and / or the abrasive 30 is supplied from the supply pipe 98 to regenerate the sponge blast medium. After the reproduction, the rotation of the drum 94 is stopped, and then the rod 116 of the hydraulic cylinder 114 is extended, the drum 94 is tilted in the direction of arrow A, and the reproduced sponge blast medium 12B is taken out from the opening end 94B of the drum 94. .

The conceptual diagram which showed the process of the sponge blasting medium reproduction | regeneration method of embodiment The side view which showed the whole structure of the sponge blasting medium reproduction apparatus of embodiment FIG. 2 is a perspective view of main parts of the sponge blast medium reproducing apparatus shown in FIG. Sectional drawing of the support structure of the hollow rotating shaft of the sponge blast medium reproducing apparatus shown in FIG. Graph showing the proportional relationship between the hardness of the sponge piece and the binder mass Explanatory drawing showing the structure of another embodiment of a sponge blast medium reproducing apparatus

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Sponge blasting medium reproduction apparatus, 12 ... New sponge blasting medium, 12A ... Non-reusable sponge blasting medium, 12B ... Regenerated sponge blasting medium, 14 ... Container, 16 ... Binder, 18 ... Stirring means, 20 ... Hollow rotating shaft, 22 ... supply hole, 24 ... stirring blade, 26 ... rotation mechanism, 28 ... lifting mechanism, 30 ... grinding material, 32 ... feed mechanism, 34 ... drive control unit, 36 ... feed amount control unit, 38 ... base 40, bracket, 42 ... servo motor, 44 ... screw rod, 46 ... rod, 48 ... guide cylinder, 50 ... casing, 52 ... beam, 54 ... bearing, 56 ... bearing, 58 ... column, 60 ... sliding bearing, 62 ... Servo motor, 64 ... Gear, 66 ... Gear, 68 ... Container, 70 ... Flow meter, 72 ... Electromagnetic valve, 74 ... Binder supply tube, 76 ... Hopper, 78 ... Electromagnetic valve, 80 ... Buffer container, 82 ... Mass sensor, 84 ... Electromagnetic valve, 86 ... Grinding material supply tube, 90 ... Sponge blast medium regenerator, 92 ... Stirrer blade, 94 ... Drum, 96 ... Motor, 98 ... Supply pipe, 100 ... Shaft , 102 ... Tilt base, 194 ... Bearing, 106 ... Flange, 108 ... Roller, 110 ... Hinge shaft, 112 ... Base, 114 ... Hydraulic cylinder, 116 ... Rod, 118 ... Hinge shaft, 120 ... Hinge shaft

Claims (8)

  A sponge blasting medium having a size smaller than a predetermined size is put into a container, and a predetermined amount of a binder made of an aqueous polyurethane emulsion is added to the sponge blasting medium and stirred to regenerate the sponge blasting medium of the predetermined size. A method for regenerating a sponge blasting medium.   The method for regenerating a sponge blast medium according to claim 1, wherein the amount of the binder added is 1 to 10% (w / w) with respect to the mass of the sponge blast medium before regeneration.   The stirring blade to be stirred is moved up and down in the container while rotating, and the amount of the binder added is increased when the stirring blade is lowered in the container and decreased when the stirring blade is raised. The method for regenerating a sponge blast medium according to claim 1 or 2, wherein:   4. The sponge according to claim 1, wherein the stirring blade has a smaller rotational speed when descending in the container and a larger rotational speed when rising. Blast medium playback method. A container into which a sponge blast medium of a size smaller than a predetermined size is charged;
A hollow rotating shaft inserted and disposed in the container;
A stirring blade attached to the hollow rotary shaft and formed with a supply hole communicating with a hollow portion of the hollow rotary shaft;
A rotating mechanism for rotating the stirring blade in the container by rotating the hollow rotating shaft;
A lifting mechanism that integrally lifts and lowers the rotating mechanism, the stirring blade, and the hollow rotating shaft;
A supply mechanism for adding / supplying a polyurethane aqueous emulsion binder and / or a sponge blast medium abrasive from the upper opening end of the hollow rotary shaft;
Drive control means for driving and controlling the rotation mechanism and the lifting mechanism;
A supply amount control means for controlling the addition amount / supply amount of the binder and / or the abrasive by the supply mechanism;
An apparatus for reproducing sponge blasting media, comprising:   The amount of the binder added by the supply mechanism is set to 1 to 10% (w / w) of the mass of the sponge blast medium put into the container. Sponge blasting medium playback device.   The drive control means drives and controls the elevating mechanism so that the stirring blades move up and down in the container while rotating, and the supply amount control means moves the stirring blades down in the container The apparatus for regenerating a sponge blast medium according to claim 5 or 6, wherein the addition amount is controlled so that the addition amount of the binder is sometimes increased and the addition amount of the binder is decreased when the binder is increased.   The said drive control means controls the said rotation mechanism so that a rotation speed becomes small when the said stirring blade descend | falls in the said container, and a rotation speed becomes large when it raises. Or the sponge blast medium reproducing device according to any one of 7;

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