JP2000280173A - Method and device for supplying polishing material for blasting device, and blasting device provided with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably inject the polishing material even in the case of using the polishing material having low flowability or setting a small quantity of injection by supplying the polishing material inside of polishing material tank to an injection nozzle through a polishing material guide pipe with the pulse-like compressed gas flow. SOLUTION: Outside air of a polishing material adjusting unit 3 is sucked into a diffusing unit 9 through a filter 14 by the negative pressure inside of the diffusing unit 9 so as to generate a suction air flow to a polishing material guide chamber 17 of an injection nozzle 1 through a polishing material supply pipe 2. On the other hand, when a pulse-like electrical signal generating unit 10 is operated so as to supply the predetermined pulse signal to a pulse control valve 7, since the compressed air is supplied to the pulse control valve 7 while lowering pressure of the compressed air to the predetermined pressure with a regulator, a pulse-like air flow is generated in a polishing material lead-in pipe 6, and the polishing material inside of an adjusting unit main body 4 is made to flow into the polishing material lead-in pipe 6 by the gravity in the case where an opening 5 is relatively large, and injected into a diffusing unit 9 by the pulse-like air flow.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention injects abrasives composed of natural silica sand, alumina or silicon carbide powder, glass beads, resin pellets, fine steel balls, and the like, together with a fluid such as air, from an injection nozzle at a high speed. To process the workpiece into a pattern such as satin finish, precision engraving of glass, silicon wafer, etc., engraving of plasma display ribs,
Alternatively, the present invention relates to an abrasive supply method and an abrasive supply apparatus in a blast apparatus for performing surface treatment such as pre-treatment for painting and surface processing, and a blast apparatus provided with the abrasive supply apparatus.

[0002]

2. Description of the Related Art As shown in FIG. 3, a conventional abrasive supply apparatus includes an injection nozzle 10 for injecting an abrasive by a compressed gas.
0, an abrasive supply pipe 101 for supplying an abrasive to the injection nozzle 100, and an abrasive adjuster 102 for supplying a fixed amount of abrasive to the abrasive supply pipe 101. Of the adjuster body 1
An abrasive introduction tube 105 having an opening 104 into which the abrasive in the inside 03 flows is provided. One end of the abrasive introduction tube 105 faces the outside of the side wall of the adjuster main body 103, and the other end supplies the abrasive. It communicates with the pipe 101.

[0003] More specifically, as shown in FIG. 3, a nozzle body 106 of the injection nozzle 100 is provided with an abrasive inlet 107 through an abrasive supply pipe 101 from the abrasive controller 102. An abrasive guide chamber 108 in the form of a substantially cylindrical container through which the abrasive is guided is formed, and a conical inner surface 109 formed in a conical shape at the front end of the abrasive guide chamber 108 is formed. A nozzle 110 is provided to penetrate the inside of the conical inner surface 109.
1 and the air injection tube 111 is connected to the screw 11
At 2, it is fixed to the rear part of the nozzle body 106, and the air injection pipe 111 reaches a compressed air supply source (not shown) via a compressed air supply pipe 113.

In the conventional abrasive supply apparatus having the above-described configuration, when compressed air from a compressed air supply source (not shown) is injected from the tip of the air injection pipe 111 toward the nozzle 110, the inside of the abrasive guide chamber 108 becomes negative. Pressure, the negative pressure causes the abrasive supply pipe 101 and the abrasive introduction pipe 105.
Inside also becomes negative pressure. Due to the negative pressure in the abrasive introduction pipe 105, air outside the abrasive adjuster 102 is moved to the abrasive introduction pipe 1.
The air is sucked into the nozzle 05 and flows through the abrasive supply pipe 101 to the abrasive guide chamber 108 of the spray nozzle 100.
When the opening 104 is relatively large, the abrasive in the adjuster main body 103 flows down into the abrasive introduction pipe 105 by gravity, accumulates in the abrasive introduction pipe 105 so as to form a cone, and the air flow Is sucked into the abrasive material guiding chamber 108. On the other hand, when the opening 104 is relatively small, the abrasive does not flow down into the abrasive introduction pipe 105 due to gravity. The abrasive guide chamber 10 of the injection nozzle 100 is sucked into the inside of the spray nozzle 100 through the abrasive supply pipe 101.
Aspirated to 8. The abrasive in the abrasive guide chamber 108 is guided to the annular gap between the inner surface 109 of the cone and the outer periphery of the air injection pipe 111, accelerates on the air flow of the air injection pipe 111, and is accelerated by the nozzle 110 to cover the outside. Injected into the workpiece.

[0005] Further, as another example of the abrasive controller 102, a first abrasive inlet pipe in which an abrasive inlet pipe is connected to an abrasive supply pipe, and a second abrasive inlet pipe facing outward. The first abrasive material introduction pipe is made to face the opening of one end of the first abrasive material introduction pipe through a gap in the adjuster body. In the abrasive material adjuster configured as described above, the opening into which the abrasive in the adjuster body flows is formed in a ring shape, and the opening is turned sideways, so that the polishing by gravity as described above is performed. There is a feature that the material does not easily flow down.

[0006]

In blasting, it is known that an abrasive which collides with an article to be processed and changes its traveling direction collides with an abrasive injected later. This collision is more remarkable as the value (referred to as the injection density) obtained by dividing the amount of the abrasive material injected from the injection nozzle 100 per unit time (referred to as the injection amount) by the sectional area of the nozzle 110 is increased. And when the injection density is low,
The processing efficiency increases in proportion to the increase in the injection amount, but when the injection density is high, the processing efficiency does not become high despite the increase in the injection amount due to the impact of the collision, and further, when the injection density is increased, On the contrary, the processing efficiency decreases. Therefore, in order to increase the processing efficiency, it is necessary to employ a lightly low injection density at which the processing efficiency does not decrease. Further, at this time, energy wasted is wasted on abrasives that do not contribute to the processing, so that setting a low injection density is also important in terms of abrasive recycling.
The cross-sectional area of the injection port is empirically set to It should be less than about 5 square centimeters. This is because if the cross-sectional area of the injection port is increased, the abrasive can be sprayed over a wide range, but in the range, there is a problem that a difference between a portion having a large injection amount and a portion having a small injection amount becomes large. In order to set the injection density low, it is preferable to set the injection amount small.

However, in the conventional abrasive supply apparatus for blasting, if the opening 104 is made smaller in order to reduce the injection amount, the abrasive in the adjuster body 103 is intermittently introduced from the opening 104 through the abrasive. When a phenomenon in which the injection amount is not stabilized by being sucked into the pipe 105 (referred to as a breathing phenomenon), or particularly when an abrasive having low fluidity is used,
There was a problem that the phenomenon that the abrasive in the adjuster body 103 was not sucked into the abrasive introduction pipe 105 from the opening 104 into the abrasive introduction pipe 105 (called a bridge phenomenon) easily occurred. Further, if the injection amount is to be changed in order to properly set the injection density in accordance with a change in other processing conditions, the abrasive introduction tube 105 is replaced with an abrasive introduction tube having an opening of another size. You can't do it. That is, the amount of projection could not be arbitrarily controlled, and this remained an issue.

[0008] The present invention has been made in view of the above circumstances, it is possible to stably spray the abrasive even if a low-fluid abrasive is used or the injection amount is set to a small amount. It is an object of the present invention to provide an abrasive supply method in a new blast apparatus in which the injection amount can be easily adjusted, an abrasive supply apparatus in the blast apparatus, and a blast apparatus provided with the abrasive supply apparatus.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides a method for supplying an abrasive in an abrasive tank to an injection nozzle through an abrasive guide tube by a pulsed compressed gas flow. A method for supplying an abrasive in a blasting apparatus, an injection nozzle for injecting an abrasive by a compressed gas, an abrasive guide tube for supplying an abrasive to the injection nozzle, and a fixed amount of abrasive in the abrasive guide tube A polishing agent introduction pipe provided with an opening through which an abrasive in the adjustment device body flows, the polishing agent introduction pipe being provided in the adjustment body of the polishing agent adjustment apparatus. Is connected to a pressure gas supply via a pulse control valve,
An abrasive supply device in a blast device, the other end of which is communicated with the abrasive guide tube; an injection nozzle for injecting the abrasive by a compressed gas; and an abrasive for supplying the abrasive to the injection nozzle A guide tube, comprising an abrasive adjuster for supplying a fixed amount of abrasive to the abrasive guide tube,
The adjuster body of the abrasive adjuster is provided with an abrasive introduction pipe having an opening through which the abrasive in the adjuster body flows, and one end of the abrasive introduction pipe is connected to a pressure gas through a pulse control valve. The abrasive blast device is characterized in that an abrasive supply device, which communicates with a supply source and whose other end communicates with the abrasive guide tube, is incorporated in an abrasive supply section.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail based on illustrated embodiments. FIG. 1 shows a preferred embodiment of an abrasive supply apparatus according to the present invention, which is an injection nozzle 1 for injecting an abrasive by a compressed gas, and an abrasive for supplying the abrasive to the injection nozzle 1. A supply pipe 2 and an abrasive adjuster 3 for supplying a fixed amount of abrasive to the abrasive supply pipe 2 are provided. The abrasive in the adjuster main body 4 flows into an adjuster main body 4 of the abrasive adjuster 3. A polishing material introduction pipe 6 having an opening 5 is provided, and one end of the polishing material introduction pipe 6 is compressed outside the side wall of the adjuster body 4 via a pulse control valve 7 and a regulator 8. The other end is connected to a gas supply source, and the other end is connected to an abrasive supply pipe 2.
To the inside of the diffuser 9 communicating with. The pulse control valve 7 has a pulsed electric signal generator 1 for control.
0 is electrically connected.

The pulse control valve 7 is preferably selected from solenoid valves made so as not to fail even if they are repeatedly opened and closed at a high speed. Examples of such a solenoid valve are those manufactured by Koganei Seisakusho Co., Ltd. According to the catalog, even if the name high cycle solenoid valve performs the opening and closing operation 45 times per second, the operation is guaranteed 500 million times, so that it can be applied. Further, as the pulse signal generator 10 for repeatedly opening and closing at a high speed, for example, a twin timer product symbol H3BF manufactured by OMRON Corporation sets the on time and the off time to 0.
. This can be applied because it can be set independently in units of 01 seconds.

As shown in detail in FIG. 1, the diffuser 9 forms a diffusion abrasive discharge port 12 by squeezing the lower part of a cylindrical diffuser body 11 in a funnel shape, and forming the diffusion abrasive discharge port 12. The outlet 12 communicates with the abrasive supply pipe 2. Diffuser body 11
Is opened, and the filter 14 is screwed to the opening with the lid member 13. Although this filter 14 does not allow the abrasive material to pass through, it may be a screened mesh that easily passes outside air. The filter 14 is provided in order to prevent the abrasive sprayed on the diffuser 9 from scattering outside and deteriorating the working environment. If the filter 14 is clogged, remove the lid member 13 and replace it. Alternatively, dust or the like causing clogging is removed using a toothbrush or the like before use.

As shown in detail in FIG. 1, the nozzle body 15 of the injection nozzle 1 is connected to the abrasive introduction port 16 through the abrasive supply pipe 2 from the above-mentioned abrasive controller 3. A substantially cylindrical container-shaped abrasive guiding chamber 17 is formed in which the abrasive is guided by being connected to the inner surface. A conical inner surface 18 narrowed in a conical shape is formed at the front end of the abrasive guiding chamber 17. The tip of an air injection pipe 20 inserted from the rear of the abrasive material guiding chamber 17 is disposed inside the conical inner surface 18. This air injection tube 20 is a screw 2
At 1, it is fixed to the rear part of the nozzle body 15. Further, the air injection pipe 20 communicates with a compressed air supply source (not shown) via a compressed air supply pipe 22.

In the abrasive supply apparatus thus configured, when compressed air from a compressed air supply source (not shown) is jetted from the tip of the air injection pipe 20 toward the nozzle 19, the inside of the abrasive guide chamber 17 becomes negative pressure. Therefore, the negative pressure also causes the abrasive material supply pipe 2 and the diffuser 9 to have a negative pressure. Due to the negative pressure in the diffuser 9, air outside the abrasive conditioner 3 passes through the filter 14 and is sucked into the diffuser 9, passes through the abrasive supply pipe 2, and the abrasive guide chamber 17 of the injection nozzle 1. Produces a suction air flow to the On the other hand, when the pulse-like electric signal generator 10 is operated to supply a predetermined pulse signal to the pulse control valve 7, compressed air from a compressed air supply source (not shown) is supplied to the pulse control valve 7 by the regulator 8 at a predetermined pressure. When the opening 5 is relatively large, the abrasive in the adjuster body 4 is urged by gravity to generate a pulsed air flow in the abrasive introduction pipe 6. And is accumulated in the abrasive introduction pipe 6 so as to form a cone, and is injected into the diffuser 9 by the pulsed air flow. On the other hand, when the opening 5 is relatively small, the abrasive does not flow down into the abrasive introduction pipe 6 due to gravity. 6 and is injected into the diffuser 9 by the pulsed air flow. The abrasive sprayed into the diffuser 9 is dispersed and averaged in the diffuser 9 and is continuously sucked into the abrasive guide chamber 17 by the suction air flow. The abrasive in the abrasive guide chamber 17 is guided into the annular gap between the inner surface 18 of the cone and the outer periphery of the air injection pipe 20, accelerates on the air flow of the air injection pipe 20, and is accelerated by the nozzle 19. Injected into the workpiece. Since the effect of averaging the abrasive also occurs in the abrasive supply pipe 2, if the abrasive supply pipe 2 is sufficiently long, the diffuser 9
Need not be provided.

Further, the pulsed air flow applies pulse-like vibration to the abrasive near the opening 5 in the adjuster body 4, and the vibration loosens the abrasive to suppress a breathing phenomenon and a bridging phenomenon. . It is sufficient that the pressure of the compressed air supplied to the pulse control valve 7 to generate the pulsed air flow is about 2 kg per square centimeter.

The relationship between the on-time and off-time ratio (the value obtained by dividing the on-time by the off-time) and the injection amount when the on-time of the pulse is fixed and the off-time of the pulse is increased or decreased is shown. It is shown in FIG. According to FIG. 4, the ratio between the on-time and the off-time and the injection amount are substantially proportional.
If the ratio between the on-time and the off-time is set to 0.111, the injection amount can be 128 g per minute, and if the ratio between the on-time and the off-time is set to 0.026, about 28% of the injection amount can be obtained. The injection amount can be 35 g per minute. In addition, the setting is easy only by adjusting the knob of the pulse-like electric signal generator. The on-time is fixed to 0.01 second, compressed air is supplied to the pulse control valve 7 at a pressure of 2 kg per square centimeter, the opening is 3 mm, and a steel pipe having an inner diameter of 4 mm is used as the abrasive introduction pipe 6. # 20 widely used for abrasives
Measured using a 00 white alundum.

Next, FIG. 2 shows a blast apparatus according to an embodiment of the present invention. In FIG. 2, an injection nozzle 25 extending from an abrasive material adjuster 24 is fixed in a processing chamber 23,
The injection nozzle 25 communicates with a compressed air supply source (not shown) via a compressed air supply pipe 45, an injection control valve 26, a regulator 27, and an air filter 28. The branch pipe 29 branched from the compressed air supply pipe 45 communicates with the pulse control valve 31 via the regulator 30, and the pulse control valve communicates with the abrasive introduction pipe 46 outside the side wall of the regulator main body 32. The other end of the abrasive introduction pipe 46 communicates with the spray nozzle 25 via the diffuser 33 and the abrasive supply pipe 34 to form the abrasive adjuster 24 having the same operation as that described in detail above. are doing. Further, a hopper 54 which is a cylindrical container for storing the abrasive to be supplied to the adjuster main body 32 is formed continuously above the adjuster main body 32.

The outside air inlet 3 is provided on the side wall of the processing chamber 23.
5 and a door 36 are formed, and the lower part thereof is squeezed into a funnel shape to communicate with a dust collector 40 via an abrasive recycling pipe 37, a cyclone 38 and a dust collection pipe 39. Cyclone 38
Is connected to a buffer tank 42 through a valve configured to be openable and closable by an air cylinder 41, and the buffer tank 42 is connected to a hopper 54 through a valve configured to be openable and closable by an air cylinder 43 below. . The foot switch 44 is connected to a not-shown conventional electric circuit, and by operating the foot switch 44, the injection control valve 26 and the pulse control valve 3 are operated.
1, the air cylinders 41 and 43 and the dust collector 40 are configured to operate, and the air cylinder 41 and the air cylinder 4
3 expands and contracts alternately.

In the blasting apparatus according to the present embodiment, the door 36 is opened and the work W
And the foot switch 44 is operated, the injection control valve 26, the pulse control valve 31, the air cylinders 41 and 43, and the dust collector 4 are operated by a conventional electric circuit (not shown).
0 starts operation. When the injection control valve 26 is opened, the abrasive reduced to a predetermined amount by the pulsed compressed air from the abrasive controller 24 is supplied to the injection nozzle 25 and accelerated by the compressed air flow supplied by the compressed air supply pipe 45. The predetermined processing can be started by being injected from the injection nozzle 25 to the workpiece W.

The abrasive and the abrasive dust scattered into the processing chamber 23 enter the processing chamber 23 from the outside air inlet 35 due to the negative pressure generated by the dust collector 40, and the abrasive recycling pipe 3
The abrasive is guided to the cyclone 38 by 7, and the abrasive collects in the lower part of the cyclone 38, but the abrasive dust is carried by the dust collecting tube 39 to the dust collector 40 and stored therein. When the valve is opened by the air cylinder 41, the abrasive accumulated in the lower part of the cyclone 38 falls into the buffer tank 42. At this time, the valve reaching the hopper 54 by the air cylinder 43 is closed, so that the abrasive controller 24 The abrasive in the buffer tank 42 is not carried to the dust collector 40 by the airflow from the air to the cyclone 38. Next, when the valve is opened by the air cylinder 43, the abrasive accumulated in the buffer tank 42 falls into the hopper 54. At this time, the valve reaching the cyclone 38 by the air cylinder 41 is closed. The abrasive in the hopper 54 is not carried to the dust collector 40 by the airflow from the 24 to the cyclone 38. In this way, the polishing material from which the polishing dust has been removed can be circulated and used to continue good and continuous processing. Then, when the predetermined processing is completed, the operation is ended by operating the foot switch 44, and the polished object W having completed the predetermined processing can be taken out by opening the door 36 and sent to the next step.

[0021]

As described above, the present invention has the following effects. Even if an abrasive having low fluidity is used, the breathing phenomenon and the bridging phenomenon are less likely to occur, and the breathing phenomenon and the bridging phenomenon are less likely to occur even if the injection amount is set small. In addition, it is easy to change the injection amount over a wide range, and it is easy to set an optimum injection amount according to the injection nozzle used. In addition, an injection nozzle having a small nozzle diameter that is easily clogged can be used if the injection amount is set to a small value, but if such an injection nozzle is used, the abrasive can be selectively injected only to a necessary portion. It is efficient. Further, the abrasive supply device for that purpose has a simple structure and has no sliding portion, so that the device can be manufactured at low cost and there is no problem of wear of the device during operation. In addition, since the structure of the blasting device is simple and the blasting device does not significantly increase in size, the blasting device can be manufactured easily and inexpensively even if newly manufactured, and the conventional blasting device in use must be modified. Therefore, it can be easily spread in the conventional processing steps.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view showing a preferred embodiment of an abrasive supply device according to the present invention.

FIG. 2 is a partially cutaway front view schematically showing a preferred embodiment of a blast device according to the present invention.

FIG. 3 is a partially cutaway front view showing an example of a conventional abrasive supply device.

FIG. 4 is a graph showing a relationship between a ratio between an on-time and an off-time and an injection amount.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Injection nozzle 2 Abrasive supply pipe 3 Abrasive adjuster 4 Adjuster body 5 Opening 6 Abrasive introduction pipe 7 Pulse control valve 9 Diffuser 10 Pulsed electric signal generator 11 Diffuser 14 Filter 15 Nozzle body 16 Abrasive Inlet 17 Abrasive material induction chamber 19 Nozzle 20 Air injection pipe 22 Compressed air supply pipe 23 Processing chamber 24 Abrasive material regulator 26 Injection control valve 31 Pulse control valve 32 Regulator body 33 Diffuser 34 Abrasive material supply pipe 37 Abrasive material recycling Pipe 38 Cyclone 39 Dust collection pipe 40 Dust collector 42 Buffer tank 45 Injection nozzle 46 Abrasive introduction pipe 54 Hopper

Claims (5)

[Claims] 1. A method for supplying an abrasive in a blasting apparatus, comprising supplying an abrasive in an abrasive tank to an injection nozzle through an abrasive guide tube by a pulsed compressed gas flow. 2. The blast apparatus according to claim 1, wherein the supply amount of the abrasive supplied to the injection nozzle is adjusted by increasing or decreasing a ratio of an on-time to an off-time of a pulse in the pulsed compressed gas flow. Abrasive supply method. 3. An injection nozzle for injecting an abrasive by compressed gas, an abrasive guide tube for supplying an abrasive to the injection nozzle, and an abrasive adjuster for supplying a fixed amount of abrasive to the abrasive guide tube. The abrasive body adjuster body is provided with an abrasive introduction pipe having an opening through which the abrasive in the adjuster body flows, and one end of the abrasive introduction pipe is provided with a pulse control valve. An abrasive supply device in a blast device, wherein the abrasive supply device communicates with a pressurized gas supply source through the other end and the other end communicates with the abrasive guide tube. 4. The abrasive supply device in a blasting device according to claim 3, wherein the abrasive introduction pipe communicates with the abrasive guide pipe via a diffuser. 5. An injection nozzle for injecting an abrasive by a compressed gas, an abrasive guide tube for supplying an abrasive to the injection nozzle, and an abrasive controller for supplying a fixed amount of abrasive to the abrasive guide tube. The abrasive body adjuster body is provided with an abrasive introduction pipe having an opening through which the abrasive in the adjuster body flows, and one end of the abrasive introduction pipe is provided with a pulse control valve. A blasting device, wherein an abrasive supply device, which communicates with a pressure gas supply source via the other end and the other end of which is connected to the abrasive guide tube, is incorporated in an abrasive supply unit.