JP2011218465A - Grinding apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grinding apparatus that enables all the abrasive grains to be reliably collected on the peripheral surface side of a bladed wheel, and also recovered without injection in a useless direction, thereby achieving intense injection from a nozzle.SOLUTION: The grinding apparatus includes: a sealable operation chamber; a hopper continuously arranged in the lower part of the chamber: and an injection apparatus supplied with abrasive grains through a fall cylinder from the hopper, and injecting the abrasive grains into the inside of the operation chamber through the nozzle. The injection apparatus is constituted such that the bladed wheel has two disks sandwiching a plurality of blades, a belt is wound around the bladed wheel so that part of peripheral surface of the bladed wheel is opened, and the front side disk has a throw-in opening of the abrasive grains facing the fall cylinder. The blades are formed into a wedge shape which becomes thicker as they go further from the central side of the bladed wheel to the peripheral surface side. Flange plates are integrally formed in the perpendicular direction to both side surfaces where the blades are brought into contact with the two disks, respectively, and a material to constitute the blades is constituted of a material having a higher abrasion resistance than a material constituting the disks.

Description

  The present invention relates to an improvement of a grinding apparatus that injects abrasive grains using centrifugal force generated by an impeller.

  As a prior art related to this type of grinding apparatus, there is an invention described in Patent Document 1. This patent invention, which the present applicant has, uses an impeller as an abrasive grain spraying device, and by supplying the sprayed abrasive grains again to the spraying device by a feeder, the waste of abrasive grains is reduced. It is lost. In addition, since the workpiece is placed in a sealed work chamber and the abrasive grains are sprayed, the dissipation of the abrasive dust is prevented and the working environment is improved.

  However, in this apparatus, the abrasive grains dropped by the blades of the inclined impeller bounce in the center direction and the movement to the peripheral surface side is hindered, and a part of the abrasive grains diffuses to the peripheral surface of the impeller. There was a problem that it was not possible.

  Therefore, the present applicant has improved this apparatus and proposed a grinding apparatus described in Patent Document 2. The apparatus of the present invention receives a supply of abrasive grains from a hopper that can be hermetically sealed, a hopper continuously provided at a lower portion thereof, and a dropping cylinder from the hopper, and injects the abrasive grains into the work chamber. The injection device is formed by winding a belt around an impeller sandwiching a plurality of blades with two discs so as to open a part of the peripheral surface, and the other of the impellers. The disc is configured by a plurality of repelling plates extending from the fixed portion of the drive shaft toward the outer periphery so as to be rotatable together with the impeller.

  With the apparatus having such a configuration, the abrasive grains are sprayed upward from the spray apparatus toward the working chamber, and the sprayed abrasive grains are supplied again to the spray apparatus via the hopper and the dropping cylinder. The flip plate rotates together with the impeller and blows off the abrasive grains at the edge thereof, thereby diffusing the abrasive grains on the peripheral surface side of the impeller.

Japanese Patent No. 3574593 Japanese Patent No. 3588284

  However, the above-described grinding apparatus described in Patent Document 2 has a problem that the structure becomes complicated by providing a plurality of repelling plates, and it takes time to assemble, and the entire apparatus is expensive.

  On the other hand, if a configuration without a repelling plate is used, the blades become worn and round as the blades impinge on the blades as they are used, and the dropped abrasive particles are splashed toward the center of the impeller. Thus, there remains a problem that hinders the movement of the abrasive grains toward the peripheral surface.

  In addition, although the blade is sandwiched by a suitable means with respect to the disc, as the apparatus is used, the accumulated abrasive grains also act on the disc at the joint corner between the blade and the disc. The problem of wearing the corners also remains.

  Therefore, a method of controlling the movement of the abrasive grains by searching for a blade having a complicated structure and changing the shape and structure of the blade itself is sought.

  On the other hand, for example, as in Patent Document 2, the abrasive grains collected on the peripheral surface of the impeller are gradually diffused on the outer peripheral surface of the impeller by the wind pressure and centrifugal force of the impeller, and are further rolled on the belt. And the belt is ejected in a tangential direction starting from a point where the belt is separated from the impeller and deviated from an acute angle formed by the belt. At this time, it is ideal that all abrasive grains accumulate in the nozzle and spray from there to grind the workpiece surface. However, due to the structure of the impeller, the belt comes into contact with the belt again from where it leaves the impeller. Until then, the peripheral surface of the impeller is open, and some abrasive grains leak from this open part, leaving another problem that all abrasive grains cannot be used effectively. Yes.

  The present invention has been made in order to solve such a problem. All the abrasive grains are surely collected on the peripheral surface side of the impeller, and the collected abrasive grains are used in a useless direction. It proposes a grinding device which has been improved so that it can be recovered without being sprayed and intensively sprayed from the nozzle.

  In order to solve the above-described problems, the present invention provides a grinding chamber of this type, a hopper that can be hermetically sealed, a hopper connected to the lower part thereof, and a supply of abrasive grains from the hopper via a dropping cylinder. And an injection device that injects abrasive grains into the work chamber through an injection nozzle. The injection device has an impeller sandwiching a plurality of blades by two discs and the circumference of the impeller. A grinding device having a belt so as to open a part of the surface, and a front side disc having an inlet for abrasive grains facing the dropping cylinder, wherein the blade is on the center side of the impeller The wedge was formed in such a way as to increase in thickness toward the outer peripheral surface.

  Thereby, the central part side becomes thin, and it is less likely that abrasive grains are splashed in the central part direction.

  Further, a means is adopted in which the gutters are integrally extended in the direction perpendicular to both side surfaces of the blades in contact with the two discs.

  And the said wing | blade employ | adopted the means of embedding and attaching a collar board to a disc so that the inner surface of a collar plate and the inner surface of a disk may become the same continuous surface.

  Moreover, the means which comprises the material which comprises a blade | wing with the material whose abrasion resistance is higher than the material which comprises a disc was employ | adopted.

  As a result, the abrasive grains accumulate on the inner surface of the blade, but the portion is less likely to be worn, and even when worn, the portion is worn uniformly.

  On the other hand, a shield plate is provided in an arc shape over the entire circumferential direction of the open portion where the belt of the impeller is not wound, and a drop plate is provided to cover the shield plate from the front side surface instead of the drop cylinder. The upper end of the dropping plate is made to face the lower end of the hopper, while the lower end is inclined to face the insertion port of the front disc.

  And the means of providing a return plate in the other end of the shielding board while connecting one end of the shielding board with the injection nozzle of an injection device was adopted.

  Further, the shielding plate is composed of a pair of inclined plates with an inverted V-shaped cross section, and the inner inclined plate faces the extension of the open portion of the blade of the impeller and is inclined by about 45 degrees on the front side of the disk. The slope plate is provided so as to protrude from the front side disc and to be inclined at an angle of about 45 degrees on the inner side as opposed to the inner slope plate.

  The inner slope plate is made of a ceramic plate and the outer slope plate is made of a rubber plate.

  As a result, the abrasive grains that have leaked radially from the open portion of the impeller collide sequentially with the inclined plate and fall to the dropping plate side, and are again supplied to the impeller from the inlet.

  The return plate is composed of two reflectors formed in a V shape that opens in the direction of the shielding plate, one reflector is provided in parallel with the belt, and the other reflector is along the peripheral surface of the impeller. Adopted the means of providing.

  And each reflecting plate employ | adopted the means of comprising with a rubber plate.

  As a result, the leaked abrasive grains are repelled, dropped to the dropping plate by the air flow, and supplied again to the impeller from the inlet.

  Since the grinding device according to the present invention having the above-described configuration is formed in a wedge shape that increases in thickness as the blades move from the center side of the impeller to the outer peripheral surface side, the roundness due to wear of the tip of the blade is reduced, It is less likely that abrasive grains are splashed to the center side of the impeller. Therefore, many abrasive grains gathered on the outer peripheral surface side of the impeller, and the amount of abrasive grains ejected from the ejection nozzle increased, making it possible to perform an efficient grinding operation.

  In addition, by providing saddle plates on both sides of the blades and attaching them to the impeller, the inner three surfaces where the abrasive grains are accumulated are made of the same material with high wear resistance. For this reason, the wear of the portion is suppressed, and even when worn, it is worn uniformly, so that a grinding device with high durability can be obtained.

  On the other hand, since the shielding plate and the return plate are provided in the open portion where the belt of the impeller is not wound, the abrasive grains leaking from the open portion can be efficiently collected and re-supplied to the impeller. Became. This also increases the amount of abrasive grains ejected from the ejection nozzle, making it possible to perform an efficient grinding operation.

1 is an overall explanatory view of a grinding apparatus according to the present invention. It is a partially cutaway perspective view of an impeller. (A) is explanatory drawing of the abrasion state of a blade | wing, (B) is a description side view of the blade | wing which concerns on this invention. It is a longitudinal cross-sectional view of an impeller. It is a partially notched perspective view of the blade | wing in other embodiment. It is explanatory drawing which shows the attachment state of a blade | wing, (A) is a partial enlarged view, (B) is sectional drawing. It is a whole explanatory view showing other embodiments of a grinding device. It is explanatory drawing of an injection apparatus. It is explanatory sectional drawing which shows the movement state of the abrasive grain by the aspect of a shielding board, and the shielding board. It is explanatory drawing of a return plate.

  Hereinafter, a preferred embodiment of a grinding apparatus according to the present invention will be described with reference to the accompanying drawings. In FIG. 1, reference numeral 1 is a work chamber that can be sealed for grinding a workpiece (work object), 2 is an injection device that injects abrasive grains toward the work chamber 1, and 3 is a work chamber from the injection device 2 1 is an injection nozzle provided toward 1. The lower part of the working chamber 1 is a hopper 1a, and a lid 1b that can be appropriately opened and closed is provided at the opening thereof so that abrasive grains are supplied to the injection device via the dropping cylinder 4. According to the said structure, the abrasive grain sprayed toward the working chamber 1 from the injection apparatus 2 is again supplied to the injection apparatus 2 from the dropping cylinder 4 via the hopper 1a, and waste of an abrasive grain is carried out. It is lost.

  The injection device 2 mainly includes an impeller 2a, an endless belt 2b wound around the impeller 2a, and three pulleys 2c and 2c arranged to wind the belt 2b with a part of the impeller open.・ Consists of As shown in FIG. 2, the impeller 2 a sandwiches a plurality of blades 22, 22,... Tilted forward in the rotation direction between the two disks 20, 21. , 21 are open. Further, in the impeller 2a, the front side disk 20 has a donut shape having an inlet 20a, and the dropping cylinder 4 faces the inside of the impeller 2a through the inlet 20a. On the other hand, a drive shaft 23 is provided on the disk 21 on the back side, and a rotational force is applied to the impeller 2a by connecting the drive shaft 23 to a motor or the like.

  In this apparatus, the abrasive grains thrown into the impeller 2a from the dropping cylinder 4 are gradually diffused to the outer peripheral surface of the impeller 2a by the wind pressure and centrifugal force generated by the rotating vane 22 and formed by the blade 22 and the belt 2b. The belt 2b is jetted in a tangential direction starting from the point where the belt 2b is separated from the impeller 2a, passes through the jet nozzle 3 and reaches the workpiece. In this way, the workpiece is ground.

  Next, FIG. 3 will be described. In the apparatus having the above-described configuration, the blade 22 wears and rounds at the tip portion where abrasive grains collide as it is used, and at the same time the acute angle portion formed by the blade 22 and the belt 2b on which the abrasive grains accumulate. The blade 22 is worn by the abrasive grains, and the entire blade 22 is slightly thinned (see the hatched portion in FIG. 4A). Then, the abrasive grains thrown in from the dropping cylinder 4 are often splashed toward the central portion of the impeller 2a by the tips of the blades 22, and the movement of the abrasive grains toward the outer peripheral surface side is hindered. Therefore, the amount of abrasive grains to be sprayed is relatively reduced, and the grinding action by the abrasive grains is reduced.

  Therefore, in the present invention, as shown in FIG. 4B, the entire thickness of the blade is made thinner than that of the conventional blade, and the side surface shape is increased from the center side of the impeller 2a toward the outer peripheral surface side. It was decided to form a wedge shape. Thereby, the roundness of the blade tip portion is reduced, and the abrasive grains are less likely to be splashed toward the center portion. Therefore, many abrasive grains gather on the outer peripheral surface side, and the amount of abrasive grains sprayed for grinding also increases. In FIG. 5B, the dotted line represents the size of a conventional blade, and the hatched portion represents a worn portion.

  On the other hand, considering the overall structure of the impeller 2a with reference to FIG. 4, the blades 22 are preferably formed of a highly wear-resistant material in order to keep the degree of wear low. Further, since the front and back disks 20 and 21 have a small contact pressure received from the abrasive grains, a material having lower wear resistance than the blade 22 main body can be used. In particular, considering the cost aspect, the high wear-resistant material is expensive. Therefore, it is reasonable to use different materials for the blade 22 main body and the two disks 20 and 21, thereby reducing the cost.

  So, for example, if the abrasive has a large grinding force for roughing, the blade is boron carbide, the disc is cemented carbide, and if the abrasive is for Chuken, the blade is cemented carbide. When the disc is alumina ceramic, and the abrasive is for finishing, the blade can be alumina ceramic, and the disc can be ultra high molecular weight polyethylene. That is, different materials are used for the blade main body and the disc, and a material having higher wear resistance than the material constituting the disc is adopted as the material constituting the blade.

  Incidentally, in FIG. 4, the accumulated abrasive grains act on the discs at the joining corners (shaded portions in the figure) between the blades 22 and the discs 20 and 21 to wear the corners. As described above, it is preferable to use a material having lower wear resistance than the blade as the whole disk, but it is preferable that the joint corner portion of the disk does not wear.

  Therefore, as another embodiment of the present invention, the configuration of the blade may be a shape as shown in FIGS. That is, in FIG. 5, reference numeral 22 a denotes a blade body, which is formed by integrally extending gutter plates 22 b and 22 b in a direction perpendicular to both sides in contact with the disk. The blade body 22a is formed in a wedge shape that increases in thickness from the center side of the impeller 2a to the outer peripheral surface side, as in the above embodiment. Further, the side plate 22b has a side surface that is the same as the one surface of the blade main body, and has a U-shaped cross section so that abrasive grains accumulate on the inner side surface.

  And this blade | wing is attached so that the gutter plate 22b may be embedded in the discs 20 and 21, as shown in FIG. That is, the inner surface of the flange plate 22b and the inner surfaces of the discs 20 and 21 are made to be the same continuous surface. Thereby, there is no useless uneven part on the disk surface in appearance, and only the blades stand upright at right angles as in the conventional case.

  The blades are preferably integrally formed of a material with high wear resistance, and boron carbide, cemented carbide, alumina ceramic, or the like can be arbitrarily selected depending on the grinding force of the abrasive grains used. As a result, the three surfaces where the abrasive grains accumulate are made of the same material with high wear resistance, so the portions are not easily worn and even when worn.

  7 to 10 show still another embodiment of the grinding apparatus according to the present invention. As described above, the abrasive grains thrown into the impeller 2a are gradually diffused to the outer peripheral surface of the impeller 2a by the wind pressure and centrifugal force of the impeller 22 and are formed at an acute angle portion formed by the impeller 22 and the belt 2b. The ink is jetted in the tangential direction starting from the point where the belt 2b moves away from the impeller 2a, passes through the jet nozzle 3 and reaches the workpiece. However, as is apparent from the figure, the belt 2b is provided so as to be wound in a state where a part of the impeller 2a (upward in the figure) is opened. For this reason, some of the abrasive grains are ejected outward from this open portion, not from the ejection nozzle 3, and leak into the apparatus chamber. Therefore, in this embodiment, a configuration is adopted in which abrasive grains leaking from the open portion are collected and re-entered into the impeller.

  That is, in FIGS. 7 to 10, reference numeral 5 denotes a shielding plate provided in an arc shape over the entire area in the circumferential direction of the open portion where the belt 2b of the impeller 2a is not wound. As shown in FIG. 9, the shielding plate 5 includes a pair of inclined plates 5 a and 5 b having an inverted V-shaped cross section, and one end in the circumferential direction is connected to the injection nozzle 3. The inner slope plate 5a faces the extension of the open portion of the blade 22 of the impeller 2a and is inclined by about 45 degrees on the front side, and the other outer slope plate 5b protrudes from the front side disk. It is tilted approximately 45 degrees in the opposite direction. Therefore, the angle formed by both the slope plates 5a and 5b is approximately 90 degrees. The inner slope plate 5a is made of a ceramic plate, and the outer slope plate 5b is made of a rubber plate.

  Further, a return plate 6 is provided on the other circumferential end of the shielding plate 5, that is, on the side where the impeller 2a and the belt 2b first contact each other. The return plate 6 includes two reflecting plates 6a and 6b formed in a V-shape that opens in the direction of the shielding plate 5 when viewed from the side. One reflector 6a is provided in parallel with the belt 2b, and the other reflector 6b is provided along the circumferential surface of the disk. Moreover, both the reflecting plates 6a and 6b are composed of rubber plates.

  Next, 7 is a dropping plate provided as a substitute for the dropping cylinder 4 and covers the shielding plate 5 and the return plate 6 from the side on the front side of the disc, while its upper end faces the hopper 1a. The lower end is inclined to face the inlet 20a of the disc 20.

  In the present embodiment having such a configuration, the abrasive grains introduced into the impeller 2a are gradually diffused on the outer peripheral surface of the impeller 2a by the wind pressure and centrifugal force of the rotating vane 22, and the impeller 22 and the belt 2b. In the same manner as the embodiment on the left, the belt 2b is accumulated in a tangential direction starting from the point where the belt 2b is separated from the impeller 2a and passes through the injection nozzle 3 to reach the workpiece. However, the abrasive grains that have leaked radially from the open part of the impeller 2a first collide with the inclined plate 5a inside the shielding plate 5, and change the angle to collide with the inclined plate 5b. And drop to the dropping plate 7 side (see arrow in FIG. 9). And the abrasive grain which fell to this dropping plate 7 side rolls along the dropping plate 7, and is again supplied to the impeller 2a from the insertion port 20a.

  Further, in the portion where the return plate 6 is provided, the reflecting plates 6a and 6b re-feed the abrasive grains that collide with the inclined plate 5a and do not reach the inclined plate 5b toward the dropping plate 7 side.

  As described above, the abrasive grains leaking from the open portion of the impeller 2a are collected again in the impeller 2a through the shielding plate 5 and the return plate 6 and are subjected to grinding work. Therefore, efficient grinding work can be performed.

DESCRIPTION OF SYMBOLS 1 Work chamber 1a Hopper 2 Injection device 2a Impeller 2b Belt 2c Pulley 3 Injection nozzle 4 Drop cylinder 5 Shield plate 5a, 5b Slope plate 6 Return plate 6a, 6b Reflector plate 7 Drop plate 20, 21 Disc 20a Input port 22 Blade 22a Blade body 22b Gutter plate 23 Drive shaft

Claims (10)

  A work chamber that can be sealed, a hopper connected to the lower part of the work chamber, and a supply of abrasive grains from the hopper through a dropping cylinder, and the abrasive grains are injected into the work chamber through an injection nozzle. The injection device is formed by winding a belt around an impeller sandwiching a plurality of blades by two discs so as to open a part of the peripheral surface of the impeller. A grinding apparatus having an inlet for abrasive grains facing the dropping cylinder on a plate, wherein the blades are formed in a wedge shape that increases in thickness from the center of the impeller toward the outer peripheral surface. apparatus.   2. A grinding apparatus according to claim 1, wherein said blades are integrally extended in a direction perpendicular to both side surfaces of said blade in contact with said two disks.   The grinding device according to claim 2, wherein the blade is embedded in a circular plate so that the inner side surface of the vertical plate and the inner side surface of the circular plate are the same continuous surface.   The grinding device according to any one of claims 1 to 3, wherein a material constituting the blade is made of a material having higher wear resistance than a material constituting the disc.   A shield plate is provided in a circular arc shape over the entire circumferential direction of the open portion where the belt of the impeller is not wound, and a drop plate is provided to cover the shield plate from the front side surface instead of the drop cylinder. The grinding apparatus according to any one of claims 1 to 4, wherein an upper end of the dropping plate faces the lower end of the hopper, and a lower end thereof is inclined toward the insertion port of the front disc.   The grinding apparatus according to claim 5, wherein one end of the shielding plate is connected to an ejection nozzle of the ejection device, and a return plate is provided on the other end of the shielding plate.   The shielding plate is composed of a pair of inclined plates with an inverted V-shaped cross section, and the inner inclined plate faces the extension of the open part of the blade of the impeller and is inclined about 45 degrees on the front side of the disk, and the outer inclined plate The grinding device according to claim 5 or 6, wherein the face plate protrudes from the front disk and is inclined by about 45 degrees inwardly of the inner slope plate.   8. The grinding apparatus according to claim 7, wherein the inner inclined plate is made of a ceramic plate, and the outer inclined plate is made of a rubber plate.   The return plate is composed of two reflectors formed in a V-shape that opens in the direction of the shielding plate. One reflector is provided parallel to the belt, and the other reflector is provided along the peripheral surface of the impeller. The grinding apparatus according to any one of claims 6 to 8.   The grinding apparatus according to claim 9, wherein each reflecting plate is formed of a rubber plate.

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