JP2011020190A - Blasting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blasting device capable of maintaining the desired performance over a long period even when very hard abrasive is used. <P>SOLUTION: The blasting device includes an abrasive tank 1, a blast nozzle 3 for projecting the abrasive toward an object, and an abrasive feeder 2 for feeding the abrasive to the blast nozzle 3. The abrasive feeder 2 includes an inner cylinder 21, a vane rotor 24 provided therein, a variable speed control motor 26 for rotating the vane rotor 24 in one direction, and an outer cylinder 22 for surrounding the inner cylinder 21. An abrasive receiving port 21a to be communicated with a lower end opening part of the abrasive tank 1 is formed in an upper surface part of the inner cylinder 21, and an abrasive discharging port 21b is formed in a bottom surface part opposite thereto. Air seal slits S1, S2 extending in the rotational axial direction of the vane rotor 24 along both edges of the abrasive receiving port 21a are formed in the inner cylinder 21, and an air supply pipe 16 for supplying air inside the inner cylinder 21 through the air seal slits S1, S2 is connected to the outer cylinder 22. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a blasting apparatus used for projecting a grinding material (blasting material) such as diamond grit or cast steel grit onto a processed material to remove a coating film, scale, rust, etc. adhering to the surface of the processed material.

  Conventionally, as such a blasting apparatus, a mixer having a flow rate adjusting mechanism is provided at the lower end of a pressurized tank that contains an abrasive, and the mixer and a compressed air supply source are connected by piping, and a nozzle is provided downstream of the mixer. What connected by piping is known (for example, patent documents 1).

  In addition, a discharge chamber is connected to the lower end discharge port of the tank for storing the abrasive (ice particles and dry ice particles) via a rotary feeder, and the discharge chamber is joined in the middle of the pressurized air pipe, upstream of the pressurized air pipe. A blasting apparatus is known in which an end is connected to a pressurized air supply source and a nozzle is connected to a downstream end of a pressurized air pipe (for example, Patent Document 2).

Japanese Patent No. 3372112 (FIG. 1) Japanese Patent No. 3264500 (FIGS. 1 and 7)

  However, according to the blast apparatus described in Patent Document 1, since the inside of the pressurized tank is maintained at a high pressure state by the compressed air supplied to the upper part thereof, grinding into the pressurized tank during use of the apparatus is performed. Since the material cannot be replenished and it is necessary to interrupt the processing each time the abrasive in the pressurized tank runs out and replenish the abrasive into the tank, there is a problem that the work efficiency is deteriorated.

  In addition, the inside of the mixer having a flow rate adjusting mechanism is extremely worn due to friction with the abrasive that falls from the pressurized tank, and therefore the flow rate adjusting function of the abrasive is lost early and the abrasive that is projected from the nozzle There is a drawback that the projection flow rate cannot be adjusted.

  In this regard, in Patent Document 2, since ice particles and dry ice particles are used as the abrasive, it is possible to continuously supply a predetermined amount of ice particles and dry ice particles to the nozzle while suppressing wear of the rotary feeder. In addition, when a hard abrasive such as diamond grit is used instead of dry ice grains, the inside of the rotary feeder wears out early, and the projection flow rate of the abrasive projected from the nozzle can be adjusted as in Patent Document 1. There is a drawback of disappearing.

  The present invention has been made in view of the above circumstances, and its main purpose is to maintain the desired performance over a long period of time even when an extremely hard abrasive such as diamond grit is used. It is an object of the present invention to provide a blasting device capable of performing the above.

In order to achieve the above object, the present invention
An abrasive tank for storing the abrasive, a blast nozzle for projecting the abrasive stored in the abrasive tank toward the workpiece, and an abrasive feeder for supplying the abrasive from the abrasive tank to the blast nozzle A blasting device comprising,
The grinding material feeder has an inner cylinder in which a grinding material receiving port communicating with a lower end opening of the grinding material tank is formed on an upper surface portion and a grinding material discharge port is formed on a bottom surface facing the grinding material receiving port. A vane rotor having a blade provided radially on the outer periphery of the rotating shaft and rotatably provided inside the inner cylinder, a variable speed rotor driving unit that rotates the vane rotor in one direction, and the inner cylinder And an outer cylinder surrounding the
The inner cylinder is formed with an air seal slit extending in the rotational axis direction of the vane rotor along at least both side edges of the abrasive receiving port,
An air supply pipe for sending air into the inner cylinder through the air seal slit is connected to the outer cylinder.

  In addition, the vane rotor is supported by the bearing unit with both end portions of the rotating shaft passing through the end plates forming both ends of the inner cylinder and the outer cylinder, and the rotating shaft is supported between the end plate and the bearing unit. A shielding pipe is provided, and a vent hole for taking in air that flows into the inner cylinder is formed in an outer peripheral portion of the shielding pipe.

  And a blast booth in which the blast nozzle is disposed, and a lower part of the blast booth and an upper part of the abrasive material tank are used to transfer the abrasive material projected from the blast nozzle onto the processed material in the blast booth. It is characterized by being connected by an air pipe that winds inside.

  According to the blasting apparatus of the present invention, the blasting apparatus includes a grinding material feeder that supplies the grinding material from the grinding material tank to the blast nozzle, the feeder having an inner cylinder in which the vane rotor is built, and the grinding material on the upper surface portion of the inner cylinder. An abrasive receiving port communicating with the lower end opening of the tank is formed, and an abrasive discharge port is formed on the bottom surface facing the abrasive receiving port, and the inner cylinder is provided on both side edges of the abrasive receiving port. An air seal slit extending in the direction of the rotation axis of the vane rotor is formed, and air is blown into the inner cylinder from the outer cylinder through the air seal slit, so that the grinding falls from the abrasive material receiving port into the inner cylinder. A predetermined amount of abrasive can be introduced between the adjacent blades while preventing the material from being caught between the blades of the vane rotor and the inner wall of the inner cylinder. Therefore, it is possible to quantitatively supply the abrasive material stored in the abrasive material tank to the blast nozzle according to the rotation amount of the vane rotor while suppressing the wear of the vane rotor and the inner cylinder.

  In addition, a shield tube that covers the rotating shaft is provided between the end plate that forms both ends of the inner cylinder and the outer tube and the bearing unit that supports the rotating shaft of the vane rotor, and air flows into the inner cylinder from the shield tube. Since it is set as a structure, a bearing unit can be protected from an abrasive.

  Also, the lower part of the blast booth where the blast nozzle is arranged and the upper part of the abrasive tank are communicated by an air pipe, and the abrasive that is projected from the blast nozzle onto the processed material in the blast booth is passed through the air pipe. Since it is configured to be blown into the tank, the surface treatment of the processed material can be continuously performed by circulating and using the abrasive.

Schematic showing a blasting apparatus according to the present invention Longitudinal sectional view of abrasive feeder used in the equipment Perspective view showing the feeder partially broken Cross section of the feeder

  Hereinafter, the present invention will be described in detail with reference to the drawings. First, the overall structure of the blasting apparatus according to the present invention will be outlined with reference to FIG. 1. Reference numeral 1 denotes an abrasive tank having a tapered lower part in a tapered shape, and an abrasive material (not shown) is accommodated therein. Abrasives are grit (grains with sharp edges) and shots (grains without sharp edges), such as silica sand, river sand, cast iron, cast steel, cut wire, alumina, silicon carbide, or slag. In this example, diamond grit, more specifically, granulated artificial diamond grit is used in this example.

  Reference numeral 2 denotes an abrasive feeder connected in communication with the lower end opening of the abrasive tank 1. The abrasive feeder 2 quantitatively supplies the abrasive contained in the abrasive tank 1 to the blast nozzle 3 downstream. . The abrasive feeder 2 and the blast nozzle 3 are connected by a vent pipe 4, and the abrasive is guided from the abrasive feeder 2 to the blast nozzle 3 through the vent pipe 4.

  The blast nozzle 3 is a tapered cylinder, the tip of which is an injection port 3a for projecting the abrasive supplied from the abrasive feeder 2 toward the workpiece, and the other end has an amount of air drawn into the blast nozzle 3. A flow rate adjusting valve 3b for adjusting the flow rate is attached.

  Reference numeral 5 denotes a blast booth into which a processing object to be processed for surface treatment is introduced. The blast nozzle 3 is disposed in a state where the tip is inserted into the blast booth 5, and the blast booth 5 The abrasive is projected toward the workpiece introduced into the interior. In particular, in this example, the inside of the blast booth 5 is in a negative pressure state, and the negative pressure causes a high-speed air flow necessary for projecting the abrasive material into the blast nozzle 3. According to this, it is possible not only to project the abrasive at high speed from the blast nozzle 3 onto the treatment in the blast booth 5 and to peel off the coating film etc. from the surface of the treatment well, but also the exfoliation and abrasive Can be prevented from diffusing outside the blast booth 5.

  In this example, the processed material is introduced into the blast booth 5 while being hung on a chain that is driven to travel, and is subjected to surface treatment while moving in the blast booth 5. The booth 5 is provided with a sealing device (not shown) that allows the processed material to pass through at the inlet / outlet of the processed material, but the present invention does not require this, and a predetermined number of processed materials are introduced into the blast booth 5. Then, batch processing may be performed.

  Further, as shown in FIG. 1, the lower part of the blast booth 5 and the upper part of the abrasive tank 1 are communicated with each other by an air feeding pipe 6, and the processed material in the blast booth 5 from the blast nozzle 3 through the air feeding pipe 6. The abrasive material projected on the air is blown to the abrasive material tank 1. 7 is a blower that becomes an air flow generation source that forms an air flow toward the abrasive tank 1 in the air pipe 6 and creates a negative pressure in the blast booth 5, and the suction port 7 a is connected to the suction header 8, The suction header 8 and the upper end of the abrasive tank 1 are connected by an intake pipe 9. Accordingly, by driving the blower 7, the air in the blast booth 5 is sucked through the suction header 8, the intake pipe 9, the abrasive tank 1, and the air feed pipe 6, and on the lower inclined surface 5 a of the blast booth 5. It is possible to return the abrasive that has fallen to the abrasive tank 1 through the inside of the air pipe 6.

  Note that the inner diameter of the air pipe 6 is extremely small as compared with the size of the upper space of the abrasive tank 1 (for example, 28 mm, the blowing air speed into the abrasive tank 1 is about 111.5 m / sec), and the intake air The inner diameter of the tube 9 is sufficiently larger than the inner diameter of the air feed tube 6 (for example, 100 mm, and the blown air speed from the abrasive tank 1 is about 8.5 m / sec). In addition, a baffle plate (not shown) is provided in the abrasive material tank 1 corresponding to the connection port of the air feed pipe 6, and the wind speed in the abrasive material tank 1 is closer to the air feed pipe 6 than the baffle plate. The area is about 6 m / second, and the area closer to the intake pipe 9 than the baffle plate is about 1 m / second. For this reason, the abrasive material blown to the abrasive material tank 1 by the air supply pipe 6 falls into the abrasive material tank 1 by its own weight without being drawn into the intake pipe 9. Further, a separator 10 is interposed in the air pipe 6, and the separator 10 and the suction header 8 are connected by an intake pipe 11. A part of the air is diverted from the air pipe 6 through the intake pipe 11.

  On the other hand, 12 is a dust collection tank for collecting dust and the like of the abrasive from the abrasive feeder 2, and a baffle plate 13 is provided in the dust collection tank 12 so as to face the upper inner wall. An inflow port 12 a is formed on the side wall of the dust collection tank 12 so as to face the baffle plate 13, and an outflow port 12 b is formed on the upper end of the dust collection tank 12. The inlet 12 a is connected to the abrasive feeder 2 via the dust pipe 14, and the outlet 12 b is connected to the suction header 8 via the intake pipe 15.

  Here, the inner diameter of the dust pipe 14 is extremely small as compared with the size of the upper space of the dust collection tank 12 (for example, 28 mm, the blowing air speed into the dust collection tank 12 is about 56 m / second), and the intake pipe 15 Is sufficiently larger than the inner diameter of the dust tube 14 (for example, 75 mm, and the blowing air speed from the dust collecting tank 12 is about 7.5 m / sec). In addition, a baffle plate 13 is provided in the dust collection tank 12 so as to face the inlet 12 a to which one end of the dust tube 14 is connected. The wind speed in the dust collection tank 12 is greater than that of the baffle plate 13 in the dust tube. The area on the 14 side is about 3.5 m / second, and the area on the intake pipe 15 side with respect to the baffle plate 13 is about 0.8 m / second. For this reason, the dust contained in the air sent from the dust pipe 14 into the dust collection tank 12 hits the baffle plate 13 and accumulates in the lower part of the dust collection tank 12, and only the air from which the dust has been removed passes through the intake pipe 15. It will flow out of the dust collection tank 12.

  In FIG. 1, 16 is an air supply pipe connecting the air outlet 7b of the blower 7 and the abrasive feeder 2, and 17 is an exhaust pipe branched from the air supply pipe 16. One end of the exhaust pipe 17 has a flow rate adjusting valve 17a. It is open to the atmosphere through. And according to this exhaust pipe 17, the excess air taken in from the outside in the blast nozzle 3 or the blast booth 5 is discharge | released outside, and the pressure and flow velocity of the air which circulates in this apparatus are maintained in a predetermined range. can do.

  Next, the structure of the abrasive feeder 2 will be described with reference to FIGS. As is apparent from FIGS. 2 to 4, the abrasive feeder 2 includes a laterally cylindrical inner cylinder 21 and an outer cylinder 22 surrounding the inner cylinder 21. Both ends of the inner cylinder 21 and the outer cylinder 22 are closed by a common end plate 23, and a loose hole 23a is formed in the center of both end plates 23, 23 as shown in FIG.

  A vane rotor 24 is rotatably provided inside the inner cylinder 21, and both end portions of the rotating shaft 24 a pass through the loose hole 23 a of the end plate 23 and are supported by the bearing unit 25. The vane rotor 24 has a configuration in which a plurality of (six in the illustrated example) blades 24b are radially attached to the outer periphery of the rotating shaft 24a, and the tip edges of the blades 24b are a certain distance from the inner peripheral surface of the inner cylinder 21. (15 mm in this example).

  In FIG. 2, reference numeral 26 denotes a rotor driving unit (variable speed control motor) that rotates the vane rotor 24 in one direction. The sprocket 26a is fixed to the output shaft of the rotor, and the sprocket 26b is fixed to one end of the rotating shaft 24b of the vane rotor 24. A chain 26c is wound between the two.

  As is clear from FIG. 2, a shield tube 27 is provided between the end plate 23 and the bearing unit 25 to cover the rotating shaft 24a. The shield tube 27 is a cylindrical metal pipe having an inner diameter larger than that of the loose hole 23a, and a vent hole 27a for connecting one end of the blower tube 16a is formed in the outer peripheral portion thereof. The shield tube 27 allows air taken into the inside thereof through the vent hole 27a to flow into the inner cylinder 21 through the loose hole 23a. According to this, the abrasive material flows out to the outside through the loose hole 23a. And the wear of the bearing unit 25 due to the abrasive can be prevented. The air supply pipe 16a is a branch of the air supply pipe 16 connected to the blower 7 shown in FIG. 1, and one end of the air supply pipe 16 is connected to the side wall portion of the outer cylinder 22 and communicates with the inside of the outer cylinder 22. ing. As is clear from FIG. 2, one end of the dust tube 14 passes through the side wall portion of the outer cylinder 22 and communicates with the inside of the inner cylinder 21.

  On the other hand, as is apparent from FIGS. 3 and 4, a laterally long abrasive receiving port 21a along the longitudinal direction is formed on the upper surface of the inner cylinder 21, and the abrasive receiving port 21a is formed on the opposing bottom surface. A grinding material discharge port 21b is formed. The abrasive receiving port 21a communicates with the lower end opening of the abrasive material tank 1 shown in FIG. 1, and the abrasive discharge port 21b communicates with the blast nozzle 3 via the vent pipe 4 shown in FIG. Is done.

  The inner cylinder 21 is formed with a plurality (three in the illustrated example) of air seal slits S1, S2, and S3 extending along the rotation axis direction of the vane rotor 24. In particular, the two air seal slits S1 and S2 are formed along both side edges of the abrasive material receiving port 21a, and the air seal slit S3 is on one side edge of the abrasive material discharge port 21b (on the rising side in the rotational direction of the blade 24b and dust). It is formed along the side edge closer to the connecting portion of the tube 14.

  These air seal slits S1 to S3 are for blowing air fed from the air supply pipe 16 into the outer cylinder 22 at a high speed toward the center of the inner cylinder 21, and among these, the air seal slits S1 and S2 are ground. The adjacent blades 24b are controlled while preventing the abrasives falling into the inner cylinder 21 from the material receiving port 21a from being bitten between the inner wall of the inner cylinder 21 and the blades 24b and wearing them out. The air seal slit S3 prevents the abrasive to be supplied to the blast nozzle 3 through the abrasive discharge port 21b from being drawn into the dust tube 14. Work.

  Therefore, according to the abrasive feeder 2 configured as described above, it is accommodated in the abrasive tank 1 according to the rotation amount (rotational speed) of the vane rotor 24 while suppressing wear of the inner cylinder 21 and the vane rotor 24. Abrasive material can be quantitatively supplied to the blast nozzle 3 and a part of dust that is lighter than the abrasive material (eg, debris of the abrasive material or coating film removed from the surface of the processed material) is put in the dust tube 14. It can be sent to the dust collection tank 12 by being put on the air flow to go.

  The preferred example of the blasting apparatus according to the present invention has been described above, but the blasting apparatus is not limited to the above example. For example, the dust tube 14 and the dust collection tank 12 may be omitted so that dust circulates with the abrasive. Alternatively, a motor having a constant rotational speed and a continuously variable transmission may be used as the rotor drive unit, and the power of the motor may be transmitted to the vane rotor 24 via the continuously variable transmission. Further, in the above example, the abrasive is projected using the negative pressure, but a blower (not shown) instead of the flow rate adjusting valve 3b is attached to one end of the blast nozzle 3 shown in FIG. The abrasive may be projected by air pressure blown into the blast nozzle 3.

DESCRIPTION OF SYMBOLS 1 Abrasive material tank 2 Abrasive material feeder 21 Inner cylinder 21a Abrasive material receiving port 21b Abrasive material discharge port 22 Outer cylinder 23 End plate 24 Vane rotor 24a Rotating shaft 24b Blade plate 25 Bearing unit 26 Variable speed control motor (rotor drive part)
27 Shield pipe 27a Ventilation hole S1, S2, S3 Air seal slit 3 Blast nozzle 5 Blast booth 6 Air supply pipe 16 Air supply pipe

Claims (3)

An abrasive tank for storing the abrasive, a blast nozzle for projecting the abrasive stored in the abrasive tank toward the workpiece, and an abrasive feeder for supplying the abrasive from the abrasive tank to the blast nozzle A blasting device comprising,
The grinding material feeder has an inner cylinder in which a grinding material receiving port communicating with a lower end opening of the grinding material tank is formed on an upper surface portion and a grinding material discharge port is formed on a bottom surface facing the grinding material receiving port. A vane rotor having a blade provided radially on the outer periphery of the rotating shaft and rotatably provided inside the inner cylinder, a variable speed rotor driving unit that rotates the vane rotor in one direction, and the inner cylinder And an outer cylinder surrounding the
The inner cylinder is formed with an air seal slit extending in the rotational axis direction of the vane rotor along at least both side edges of the abrasive receiving port,
An air supply pipe for feeding air into the inner cylinder through the air seal slit is connected to the outer cylinder. The vane rotor is supported by a bearing unit with both end portions of the rotating shaft passing through end plates forming both ends of the inner cylinder and the outer cylinder, and a shield tube that covers the rotating shaft between the end plate and the bearing unit. The blasting device according to claim 1, wherein a vent is formed in the outer peripheral portion of the shield tube for taking in air that flows into the inner cylinder. A blast booth in which the blast nozzle is disposed is provided, and a lower part of the blast booth and an upper part of the abrasive tank are provided with abrasives that are projected from the blast nozzle onto a processing object in the blast booth. The blasting apparatus according to claim 1, wherein the blasting apparatus is communicated by an air pipe for air feeding.

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