JP5826039B2 - Granule supply amount variable on-off valve and air blast device - Google Patents

Description

  The present invention relates to a granular material supply amount variable on-off valve and an air blast device incorporating the same.

In general, blasting is performed by spraying the abrasive mixture air, which is a mixture of pumped air and abrasive material, from the nozzle onto the surface of the workpiece, or by applying the abrasive material to the rotating impeller. The surface treatment is performed by projecting the abrasive material onto the surface of the object to be processed by centrifugal force. Here, in order to obtain a desired accuracy and finish on the surface of the object to be processed, it is necessary to set conditions for blasting. If the supply amount of the abrasive material varies depending on the setting of the mixing ratio between the pumping air pressure and the air volume and the abrasive material supply amount, the machining accuracy on the surface of the workpiece also varies. For this reason, conventionally, there has been proposed an air blasting apparatus incorporating a ball valve that mixes a polishing material in a fixed amount with the pumped air as shown in FIG.
An air blast device 101 shown in FIG. 7 is provided between a granular material storage tank 107 that stores the granular material 120 and an injection nozzle 105 that injects the granular material 120 together with compressed air onto the surface of a workpiece (not shown). A ball valve 110 is disposed.

  Here, the ball valve 110 is provided in the middle of the powder supply pipe 108 that connects between the lower end of the powder storage tank 107 and the mixing pipe 103 installed below the powder storage tank 107. ing. The granular material supply pipe 108 extends in the vertical direction. The mixing tube 103 extends in the horizontal direction. The ball valve 110 includes a valve seat body 111 provided in the middle of the granular material supply pipe 108 and a spherical valve body 112 provided rotatably in the valve seat body 111. The valve body 112 is formed with a through-hole penetrating from one end to the other end, and the valve body 112 rotates in the valve seat body 111 so that the powder body storage tank 107 side (inflow of the powder body) The supply amount of the granular material flowing out from the mixing tube 103 side (outflow side of the granular material) to the mixing tube 103 side is simply adjusted. The ball valve 110 has a large cross-sectional area of a passage that connects the upstream side (powder body inflow side) and the downstream side (powder body outflow side) by adjusting the rotation angle of the spherical valve body 112. The supply amount of the granular material 120 flowing from the upstream side to the downstream side is simply adjusted. The supply amount (per unit time) of the granular material 120 is determined by the size of the cross-sectional area of the passage and the differential pressure between the pressure on the upstream side and the pressure on the downstream side of the ball valve 110.

On the downstream side of the ball valve 110 of the granular material supply pipe 108, an on / off valve 113 for turning on and off the supply of the granular material is provided, and on the downstream side of the on / off valve 113 of the granular material supply pipe 108. A fixed orifice 114 having a function of keeping the flow rate constant is provided.
A pressure-feed air supply hose 102 is connected to one end of the mixing tube 103, and a blast hose 104 with an injection nozzle 105 is connected to the other end of the mixing tube 103. One end of a pressurized air introduction pipe 106 is connected to the pressurized air supply hose 102, and the other end of the pressurized air introduction pipe 106 is connected to a granular material storage tank 107.

  When the granular material 120 is sprayed onto the surface of the workpiece together with the compressed air, the ball valve 110 is opened by a predetermined amount (the opening degree depends on the supply amount of the granular material), and the mixing tube 103 with the on / off valve 113 closed. The pressurized air supply hose 102 supplies the pressurized air, and the pressurized air is introduced into the granular material storage tank 107 by the pressurized air introduction pipe 106 to pressurize the granular material storage tank 107. Then, when the on / off valve 113 is opened, the powder 120 stored in the powder storage tank 107 moves the powder supply pipe 108 in the vertical direction, that is, in the direction of gravity, the ball valve 110, the on / off valve 113, And through the fixed orifice 104 into the mixing tube 103.

Then, the granular material 120 is mixed with the pressurized air supplied from the pressurized air supply hose 102 in the mixing tube 103, flows into the blast hose 104, and is injected from the injection nozzle 105 toward the surface of the workpiece. It is.
Moreover, what is shown, for example in FIG. 8 is also known as a granule supply on-off valve used for an air blast apparatus (refer patent document 1).

  A granule supply opening / closing valve 201 shown in FIG. 8 serves to supply the granule to an air blasting apparatus, and includes a valve body 210 having a partition wall 211 therein. A first chamber 212 and a second chamber 213 are formed in the valve main body 210 by the partition wall 211. The valve main body 210 is provided with an inflow hole 214 through which compressed air and particles flow in, and an outflow hole 215 through which the compressed air and particles flow out. The inflow hole 214 and the outflow hole 215 each open to the first chamber 212. The inflow hole 214 extends in the horizontal direction, and the outflow hole 215 extends in the vertical direction orthogonal to the inflow hole 214. The valve main body 210 is provided with a control air inlet / outlet hole 216 that opens into the second chamber 213.

  In addition, a valve shaft 218 that is provided in a horizontal direction across the first chamber 212 and the second chamber 213 through the partition wall 211 so as to be movable forward and backward with respect to the valve seat 217 formed in the inflow hole 214 is provided. ing. At the end of the valve shaft 218 on the first chamber 212 side, a hemispherical valve body 219 that contacts and separates from the valve seat 217 by the advancement and retreat of the valve shaft 218 is provided. Further, the valve shaft 218 is provided with a sliding wall 220 that can slide in close contact with the inner wall of the first chamber 212. Further, the valve shaft 218 is provided with a piston 221 that advances the valve shaft 218 toward the valve seat 217 by pressurized air from the control air inlet / outlet 216.

  The valve body 210 is provided with an adjustment bolt 222 that contacts the end of the valve shaft 218 on the second chamber 213 side and determines the maximum opening degree of the valve body 219. The opening degree of the valve body 219 can be adjusted by adjusting the amount of protrusion into the second chamber 213 by rotating the adjustment bolt 222. A spring 223 is provided between the piston 221 in the second chamber 213 and the wall portion of the second chamber 213.

  In the granular material supply opening / closing valve 201, when supply of granular material to a nozzle (not shown) in the blasting chamber is stopped, pressurized air is caused to flow into the second chamber 213 from the control air inlet / outlet 216. As a result, the valve shaft 218 is slid toward the valve seat 217 via the piston 221, and the valve body 219 is brought into close contact with the valve seat 217. On the other hand, when the supply of granules to the nozzle in the blasting chamber is started, the inside of the second chamber 213 is decompressed by discharging pressurized air from the control air inlet / outlet 216. As a result, the valve shaft 218 is pulled toward the second chamber 213 via the piston 221, and the valve body 219 is separated from the valve seat 217. Then, the granular material flows into the first chamber 212 from the gap between the valve seat 217 and the valve body 219, and then the granular material flows out from the outflow hole 215, and is mixed with the pressurized air and pumped to the nozzle. It is.

Furthermore, as an on-off valve for supplying a granular material used in an air blast device, for example, the one shown in FIG. 9 is also known (see Patent Document 2).
The granular material supply opening / closing valve 301 shown in FIG. 9 is used when supplying granular material from the pressurized tank 320 to the granular material transport pipe 333, and includes a standing cylindrical valve case 310. ing. An inlet 311 is provided at the upper part of the valve case 310, and an outlet 312 is provided at the lower part of the valve case 310 and at the lower part in the vertical direction of the inlet 311. An inlet pipe 313 for quantifying the flow rate of the granular material from the pressurized tank 320 is detachably provided on the inlet side of the inlet 311.

  In addition, a cylindrical valve seat body 314 that is disposed concentrically with respect to the valve case 310 is provided between the inlet 311 and the outlet 312 of the valve case 310. A cylindrical diaphragm type valve body is provided on the outer periphery of the valve seat body 314 so as to be concentrically arranged with respect to the valve seat body 314 and capable of being crimped / removed with respect to the entire outer periphery of the valve seat body 314. 315 is installed. An annular opening / closing path 316 is formed between the outer periphery of the valve seat 314 and the inner periphery of the valve body 315 between the inlet 311 and the outlet 312.

Further, a granular material passage space 317 in which the inflow port 311 and the outflow port 312 communicate with the annular opening / closing path 316 is formed on the upper surface portion and the lower surface portion of the valve seat body 315.
A mixing joint 332 extending in the horizontal direction is connected to the outlet 312 of the valve case 310. A pressure feed air supply hose 331 is connected to one end of the mixing joint 332, and a granular material transport pipe 333 is connected to the other end of the mixing joint 332.

When the granular material is injected onto the surface of the workpiece together with the pressurized air, the pressurized tank 320 is first pressurized with the annular opening / closing path 316 closed, and then the pressurized air supply hose 331 is supplied to the mixing joint 332. In this way, the pressurized air is fed in and the pressurized fluid in the valve working space is exhausted. Then, the pressure of the valve body 315 to the valve seat body 314 is released by the air pressure in the pressurized tank 320, and the annular opening / closing path 316 is opened. As a result, the granular material supply opening / closing valve 301 is opened, and the granular material in the pressurized tank 320 flows substantially in the direction of gravity and enters the mixing joint 332 through the opening / closing valve 301.
The granular material is mixed with the pressurized air supplied from the pressurized air supply hose 331 in the mixing joint 332, flows into the granular material transport pipe 333, and is sprayed from the spray nozzle toward the surface of the workpiece. It is done.

Japanese Patent No. 2789513 JP 2008-81289 A

However, the air blast device 101 incorporating the conventional ball valve 110 shown in FIG. 7, the granule supply on / off valve 201 used in the air blast device shown in FIG. 8, and the powder used in the air blast device shown in FIG. The granule supply opening / closing valve 301 has the following problems.
That is, in the case of the air blast device 101 incorporating the ball valve 110 shown in FIG. 7, the ball valve 110 rotates in the valve seat body 111 and the valve seat body 111 provided in the middle of the granular material supply pipe 108. It consists of a spherical valve body 112 provided freely. The ball valve 110 has a cross-sectional area of a passage that communicates the upstream side (inflow side of the granular material) and the downstream side (outflow side of the granular material) by adjusting the rotation angle of the spherical valve body 112. Is adjusted, and the supply amount of the granular material 120 flowing from the upstream side to the downstream side is adjusted.

  However, the adjustment of the opening degree (the size of the passage cross-sectional area) by adjusting the rotation angle of the spherical valve body 112 is greatly different only by slightly changing the rotation angle of the valve body 112. It is difficult to adjust the opening. For this reason, the stable supply amount of the granular material 120 cannot be obtained. Further, the granular material 120 is caught between the rotating valve body 112 and the valve seat body 111, and the rotation failure of the valve body 112 is likely to occur. Furthermore, when the valve body 112 is frequently used, there is a problem that the valve body 112 and the valve seat body 11 are worn quickly.

  In the case of the granule supply on / off valve 201 used in the air blasting apparatus shown in FIG. 8, the inflow hole 214 and the outflow hole 215 are open to the first chamber 212 respectively, but the inflow hole 214 extends in the horizontal direction. The outflow hole 215 extends in the vertical direction perpendicular to the inflow hole 214. Since the inflow hole 214 extends in the horizontal direction, the pressurized granule is biased downward by its own weight at the inflow hole 214 and the valve seat 217, and against the hemispherical valve body 219 that contacts the valve seat 217. Not evenly distributed around the circumference. For this reason, when the valve body 219 is opened and the granule flows into the first chamber 212 from the gap between the valve seat 217 and the valve body 219, the supply amount of the granule is relative to the valve body 219. Therefore, there is a problem that the upper part becomes smaller than the lower part. In addition, when the compressed air and the granular material flow into the first chamber 212, the inner wall of the first chamber 212 and the sliding wall 220 are always in contact with the granular material, and slide in a sliding state. Since the wall 220 slides, there is a problem that the particles are caught in the sliding surface. Moreover, when the hardness of a granule is hard, there exists a problem that the valve body 219 wears out or the coaxiality of the valve seat 217 and the valve body 219 shifts | deviates, and the motion of the valve body 219 is not stabilized. Furthermore, there is also a problem that the particles enter the sliding portion of the through hole of the partition wall 211 that penetrates the valve shaft 218 and wear increases. Further, by adjusting the amount of protrusion into the second chamber 213 by rotating the adjustment bolt 222, the opening degree of the valve body 219 can be adjusted. However, if the pressure of the pumped air and the ejection pressure of the particles change. The position of the valve body 219 is changed by the spring 223, and the supply amount of the compressed air and the granular material is changed. That is, there is a problem in the accuracy of the reproducibility of the supply amount of the granular material at the opening position of the valve body 219.

Further, in the case of the granular material supply opening / closing valve 301 used in the air blasting apparatus shown in FIG. 9, an orifice pipe for quantifying the flow rate of the granular material from the pressurized tank 320 on the inlet side of the inlet 311. 313 is provided so as to be detachable, and there is a problem that the supply amount of the granular material cannot be continuously changed.
Accordingly, the present invention has been made to solve the above-described problems, and its purpose is to adjust the size of the cross-sectional area of the passage formed between the opening of the valve seat body and the valve body. The amount of powder supplied can be changed continuously, and the amount of powder supplied in the adjusted cross-sectional area of the passage can be continuously stabilized with high accuracy and no variation. An object of the present invention is to provide a granular material supply variable open / close valve with improved accuracy and an air blast device incorporating the same.

  In order to solve the above problems, the granular material supply amount variable on-off valve according to claim 1 of the present invention is a granular material used when supplying granular material from a granular material storage tank to an injection nozzle. A supply amount variable on-off valve, which is provided at an upper chamber having an inflow port through which the compressed air and the granular material from the granular material storage chamber flow, and an upper and lower direction with respect to the upper chamber. And a lower chamber having an outlet through which the granular material flows out, and the upper and lower chambers are provided in the valve body so as to separate the upper chamber and the lower chamber and penetrate in the vertical direction. A valve seat body having an opening with a circular cross section that communicates with the valve body, a valve shaft that is vertically movable with respect to the valve body so as to penetrate the opening of the valve seat body in the vertical direction, and the valve axis A spherical valve body that is provided at a lower end and is provided below the valve seat body, and that opens and closes the opening of the valve seat body by moving the valve shaft in the vertical direction. By adjusting, the size of the cross-sectional area of the passage formed between the opening of the valve seat body and the spherical valve body is adjusted, and between the opening of the valve seat body and the spherical valve body Adjusting means for adjusting the supply amount of the granular material flowing into the lower chamber from the upper chamber through the formed passage, and the input amount of the granular material charged from the inlet of the upper chamber is Regardless of the case where the granular material falls freely and the case where the granular material falls by being pressurized by compressed air, it is formed between the opening of the valve seat body and the spherical valve body. From the maximum supply amount of powder that flows into the lower chamber through the passage Become so many, it is characterized by setting the opening area of the inlet.

Here, the supply amount of the granular material flowing into the lower chamber through the passage formed between the opening of the valve seat body and the spherical valve body is determined by the cross-sectional area of the passage, the pressure in the upper chamber, and the lower portion. And the pressure difference in the chamber. The cross-sectional area B of the passage is determined by the following equation when the spherical valve body is separated from the valve seat body by a distance S and when the diameter of the opening of the valve seat body is D.
Cross-sectional area of the passage B = πD × S
The aforementioned “maximum supply amount” is formed between the opening of the valve seat body and the valve shaft when the differential pressure between the pressure in the upper chamber and the pressure in the lower chamber is zero (at the time of free fall). Means the amount when the amount of powder passing through the cross-sectional area A = π / 4 · (D ² −d ² ) as viewed from above the passage becomes saturated. Here, D is the diameter of the opening of the valve seat body, and d is the diameter of the valve shaft.

Moreover, the granular material supply amount variable on-off valve according to claim 2 of the present invention is the granular material supply amount variable on-off valve according to claim 1, wherein the valve body is connected to the valve shaft. The central axis passing through the center of the valve body and the central axis of the valve axis are attached so as to be coaxial, and the valve axis is provided to be movable in the vertical direction with respect to the valve body via a slide bearing. It is a feature.
According to a third aspect of the present invention, there is provided a variable particle supply amount variable on-off valve according to the second aspect, wherein the slide bearing is disposed above the upper chamber in the valve body. And the slide bearing is isolated from the upper chamber by a sealing material.

  Furthermore, the granular material supply amount variable on-off valve according to claim 4 of the present invention is the granular material supply amount variable on-off valve according to any one of claims 1 to 3, wherein the valve shaft And a spring member that presses the valve body against the valve seat body, and pushes down the valve shaft against an urging force of the spring member by an ON operation, and lowers the valve shaft by an OFF operation. And an actuator for releasing the pressing force, and the valve shaft is moved in the vertical direction by an on / off operation of the actuator.

Moreover, the granular material supply amount variable on-off valve according to claim 5 of the present invention is the granular material supply amount variable on-off valve according to claim 4, wherein the mass of the granular material is W and the inflow of compressed air P3 is the pressure in the upper chamber at the time, P4 is the pressure in the lower chamber at the time of inflow of pumped air, A is the cross-sectional area of the opening, Fa is the pressing force by the actuator, and the valve shaft is above the spring shaft. When the urging force to Fs is Fs, the mass W of the granular material, the pressure P3 in the upper chamber at the time of inflow of the pumped air, and at the time of inflow of the pumped air so that the following equation (1) is satisfied The pressure P4 in the lower chamber, the sectional area of the opening A, the pressing force Fa by the actuator, and the urging force Fs upward of the valve shaft by the spring member are set.
Fa >> Fs >> (A × (P3-P4) + W) (1)

Furthermore, the granular material supply amount variable on-off valve according to claim 6 of the present invention is the granular material supply amount variable on-off valve according to claim 5, wherein the pressure in the upper chamber at the time of inflow of pumping air. The pressure P4 in the lower chamber at the time of inflow of P3 and the pumping air is set so that the following equation (2) is satisfied.
P3> P4 (2)

According to a seventh aspect of the present invention, the granular material supply amount variable on-off valve according to any one of the first to sixth aspects is characterized in that the valve body Furthermore, a first pressure extraction port for extracting the pressure in the upper chamber and a second pressure extraction port for extracting the pressure in the lower chamber are provided.
Moreover, the granular material supply amount variable on-off valve according to claim 8 of the present invention is the granular material supply amount variable on-off valve according to any one of claims 1 to 7, wherein the valve body Of these, the portion forming the lower chamber is formed of a transparent member.
According to a ninth aspect of the present invention, the granular material supply variable open / close valve according to claim 9 is the powder granular material supply variable variable on / off valve according to any one of the first to eighth aspects. The body is detachably attached to the valve body, and the valve body is detachably attached to the valve shaft.

  Furthermore, an air blast device according to a tenth aspect of the present invention provides an inlet of the upper chamber of the granular material supply amount variable on-off valve according to any one of the first to ninth aspects, Connected to the powder storage tank through a body supply pipe, the outlet of the lower chamber of the powder supply variable variable on-off valve, one end is connected to the pressure air supply hose, and the other end is the injection It is characterized by being connected to a mixing tube connected to a blast hose having a nozzle.

  According to the powder supply amount variable on-off valve according to claim 1 and the air blast device according to claim 10 of the present invention, the opening of the valve seat body is adjusted by adjusting the amount of movement of the valve shaft in the vertical direction. The size of the cross-sectional area of the passage formed between the valve body and the spherical valve body is adjusted, and the lower chamber is passed through the passage formed between the opening of the valve seat body and the spherical valve body. Since the adjusting means for adjusting the supply amount of the granular material flowing into the valve body is adjusted, the size of the granular material is adjusted by adjusting the size of the cross-sectional area of the passage formed between the opening of the valve seat body and the valve body. The supply amount can be continuously changed. And by adjusting the amount of movement of the valve shaft in the vertical direction, the size of the cross-sectional area of the passage formed between the opening of the valve seat body and the spherical valve body can be adjusted. Adjustment can be performed easily.

  And, with respect to the upper chamber having an inflow port through which the compressed air and the granular material flow from the granular material storage chamber, a lower chamber having an outlet from which the compressed air and the granular material flows out is provided in the vertical direction downward, A valve seat body having a circular cross-sectional opening that penetrates in the up-down direction and communicates with the upper chamber and the lower chamber is provided so as to separate the upper chamber and the lower chamber, and the opening of the valve seat body is vertically penetrated. A spherical valve body is provided at the lower end of the valve shaft and below the valve seat body, the valve shaft is provided so as to be movable in the vertical direction relative to the valve body, and the valve seat opening is opened and closed by the vertical movement of the valve shaft. Provide. As a result, since the valve body is disposed below the valve seat body and in the direction of gravity, the powder particles are in a state of diffusive drop even if they fall freely or under pressure, and flow down stably to the opening of the valve seat body. The supply amount of the granular material flowing into the lower chamber from the upper chamber through the passage formed between the opening of the valve seat body and the spherical valve body can be stabilized. As a result, the supply amount of the granular material in the adjusted cross-sectional area of the passage can be continuously stabilized with high accuracy without variation, and the granular material supply amount variable on-off valve with improved accuracy of supply amount reproducibility. And an air blasting device.

  And, regardless of the case where the amount of the granular material charged from the inlet of the upper chamber is either the case where the granular material falls freely or the case where the granular material falls by being pressurized by the pressurized air, Since the opening area of the inlet is set so as to be larger than the maximum supply amount of the granular material flowing into the lower chamber through the passage formed between the opening of the valve seat body and the spherical valve body, Regardless of the case where the granular material falls freely and the case where the granular material falls by being pressurized by pressurized air, any state where the valve body is opened and closed with respect to the opening of the valve seat body However, the granular material always accumulates above the valve seat body in the upper chamber, and the granular material is uniformly deposited circumferentially at the opening of the valve seat body. For this reason, the supply amount of the granular material flowing into the lower chamber from the upper chamber through the passage formed between the opening of the valve seat body and the spherical valve body can be stabilized. As a result, the supply amount of the granular material in the adjusted cross-sectional area of the passage can be continuously stabilized with high accuracy without variation, and the granular material supply amount variable on-off valve with improved accuracy of supply amount reproducibility. And an air blasting device.

  Moreover, according to the granular material supply amount variable on-off valve according to claim 2 of the present invention, in the granular material supply amount variable on-off valve according to claim 1, the valve body is connected to the valve shaft. The central axis passing through the center of the valve body and the central axis of the valve axis are attached to be coaxial, and the valve axis is provided so as to be movable in the vertical direction with respect to the valve body via a slide bearing. Therefore, it is possible to avoid the eccentricity of the valve body with respect to the opening of the valve seat body. For this reason, the cross-sectional area of the channel | path formed between the opening of a valve seat body and a spherical valve body becomes equal, and the precision of the reproducibility of the supply amount of a granular material can be improved.

  Furthermore, according to the granular material supply amount variable on-off valve according to claim 3 of the present invention, in the granular material supply amount variable on-off valve according to claim 2, the slide bearing is arranged in the upper chamber of the valve body. Since the slide bearing is separated from the upper chamber by a sealing material, the powder particles do not come into contact with the slide bearing, and the biting of the powder particles can be avoided. Wear of the valve shaft due to the biting of the particles can be avoided, and the valve shaft can move smoothly.

  Moreover, according to the granular material supply amount variable on-off valve according to claim 4 of the present invention, in the granular material supply amount variable on-off valve according to any one of claims 1 to 3, A spring member that urges the valve shaft upward to press the valve body against the valve seat body, and pushes the valve shaft downward against an urging force of the spring member by an on operation; And an actuator that releases the force that pushes down the valve, and the valve shaft is moved in the vertical direction by an on / off operation of the actuator, so that the valve shaft can be moved vertically, that is, the valve body can be opened and closed with a simple configuration. it can.

Furthermore, according to the granular material supply variable open / close valve according to claim 5 of the present invention, in the granular material supply variable variable open / close valve according to claim 4, the mass of the granular material is W The pressure in the upper chamber at the time of air inflow is P3, the pressure in the lower chamber at the time of inflow of compressed air is P4, the sectional area of the opening is A, the pressing force by the actuator is Fa, and the valve by the spring member Assuming that the upward biasing force of the shaft is Fs, the mass W of the granular material, the pressure P3 in the upper chamber when the pumped air flows in, and the pumped air so that the following equation (1) holds: The pressure P4 in the lower chamber at the time of inflow, the sectional area of the opening A, the pressing force Fa by the actuator, and the urging force Fs upward of the valve shaft by the spring member are set.
Fa >> Fs >> (A × (P3-P4) + W) (1)
For this reason, since the urging force Fs upward of the valve shaft by the spring member is larger than the force obtained by adding the mass of the compressed air and the granular material, the position of the valve body relative to the valve seat body does not change due to disturbance. The supply amount of the granular material flowing into the lower chamber from the upper chamber through the passage formed between the opening of the valve seat body and the spherical valve body can be stabilized.

Moreover, according to the granular material supply amount variable type on-off valve according to claim 6 of the present invention, in the granular material supply amount variable type on-off valve according to claim 5, the inside of the upper chamber at the time of inflow of pumped air The pressure P3 and the pressure P4 in the lower chamber when the pumping air flows in are set so that the following equation (2) is established.
P3> P4 (2)
For this reason, the pressure P3 in the upper chamber when the pumped air flows in is set to be larger than the pressure P4 in the lower chamber when the pumped air flows in, and is formed between the opening of the valve seat body and the spherical valve element. It is possible to stabilize the supply amount of the granular material flowing from the upper chamber into the lower chamber through the passage.

  Furthermore, according to the granular material supply amount variable on-off valve according to claim 7 of the present invention, in the granular material supply amount variable on-off valve according to any one of claims 1 to 6, Since the valve main body is provided with a first pressure extraction port for extracting the pressure in the upper chamber and a second pressure extraction port for extracting the pressure in the lower chamber, the valve body has an internal pressure in the upper chamber extracted from the first pressure extraction port. It is formed between the opening of the valve seat body and the spherical valve body by detecting the differential pressure between the pressure and the pressure in the lower chamber taken out from the second pressure outlet and controlling the differential pressure. It is possible to further stabilize the supply amount of the granular material flowing into the lower chamber from the upper chamber through the passage.

  Moreover, according to the granular material supply amount variable on-off valve according to claim 8 of the present invention, in the granular material supply amount variable on-off valve according to any one of claims 1 to 7, Since the portion of the valve body that forms the lower chamber is formed of a transparent member, it flows from the upper chamber into the lower chamber through a passage formed between the opening of the valve seat body and the spherical valve body. The flow-down state of the granular material can be observed from the outside.

  Moreover, according to the granular material supply amount variable on-off valve according to claim 9 of the present invention, in the granular material supply amount variable on-off valve according to any one of claims 1 to 8, The valve seat body is detachably attached to the valve body, and the valve body is detachably attached to the valve shaft. Therefore, when the valve seat body or the valve body is worn, the valve seat body and the valve shaft are respectively attached to the valve body. By removing and reversing and re-attaching them to the valve body or the valve stem, the initial state can be restored, the durability of each can be doubled, and the running cost can be reduced.

It is a schematic explanatory drawing of the air blasting apparatus which concerns on this invention. It is a schematic explanatory drawing of the granular material supply amount variable type on-off valve concerning the present invention used for the air blast device shown in Drawing 1, and shows the state where the valve body closed to the opening of the valve seat body. It is a schematic explanatory drawing of the granular material supply amount variable type on-off valve based on this invention used for the air blast apparatus shown in FIG. 1, The state which the valve body opened with respect to opening of the valve seat body is shown. It is a figure for demonstrating the channel | path formed between the opening of a valve seat body, and a spherical valve body. In the air blasting apparatus shown in FIG. 1, the pressure in the pressurized air supply hose, the pressure in the granular material storage tank, the pressure in the upper chamber, the pressure in the lower chamber, and the pressure in the mixing pipe are shown. It is explanatory drawing for demonstrating. It is a figure for demonstrating the problem at the time of arrange | positioning a valve body upwards with respect to a valve seat body. It is a schematic explanatory drawing of an example of the conventional air blasting apparatus. It is sectional drawing which shows an example of the opening / closing valve for granule supply used for the conventional air blasting apparatus. It is sectional drawing which shows the other example of the opening-closing valve for granular material supply used for the conventional air blasting apparatus.

Hereinafter, a granular material supply amount variable on-off valve according to the present invention will be described with reference to the drawings.
The air blast apparatus 1 shown in FIG. 1 is between the granular material storage tank 7 which stores the granular material 40, and the injection nozzle 5 which injects the granular material 40 with pressure air on the surface of the workpiece which is not shown in figure. It has a granular material supply variable open / close valve 10 arranged.
Here, the granular material supply amount variable on-off valve 10 is a granular material supply amount variable on-off valve used when supplying the granular material 40 from the granular material storage tank 7 to the injection nozzle 5. A valve body 15 is provided between the granule storage tank 7 and the mixing tube 3.
This valve main body 15 is provided in the upper and lower direction 12 with respect to the upper chamber 12 which has the inflow port 11 into which the compressed air from the granular material storage tank 7 and a granular material flow in, and the upper chamber 12, and compressed air and powder And a lower chamber 14 having an outlet 13 through which particles flow out.

  The upper chamber 12 is formed inside a cylindrical upper chamber forming member 16, and the upper opening of the upper chamber forming member 16 is closed by an opening closing member 17. The inflow port 11 is formed at a substantially central portion of the upper chamber forming member 16 in the vertical direction, and penetrates the upper chamber 12 inside and communicates with the outside. One end of the granular material supply pipe 8 is connected to the inflow port 11, and the other end of the granular material supply pipe 8 is connected to the lower end of the granular material storage tank 7 positioned above the valve body 15. Yes.

  The lower chamber 14 is formed inside a cylindrical lower chamber forming member 18, and the lower opening of the lower chamber forming member 18 is closed by a bottom member 19. The outflow port 13 is formed at the center of the bottom member 19 and penetrates in the vertical direction so as to communicate the internal lower chamber 14 with the outside. The lower chamber forming member 18 and the bottom member 19 are formed of a transparent member (transparent resin member). A mixing pipe 3 extending in the horizontal direction is connected below the bottom member 19. As shown in FIG. 1, a powder particle introduction tube 9 is connected to the outlet 13, and this particle particle introduction tube 9 extends into the mixing tube 3. One end of the mixing pipe 3 extending in the horizontal direction is connected to the pressure air supply hose 2, and the other end is connected to a blast hose 4 having an injection nozzle 5. Further, one end of a pressurized air introduction pipe 6 is connected to the pressurized air supply hose 2, and the other end of the pressurized air introduction pipe 6 is connected to a granular material storage tank 7.

  A valve seat body 20 is provided in the valve body 15 so as to separate the upper chamber 12 and the lower chamber 14. The valve seat body 20 is detachably attached to the bottom of the upper chamber forming member 16. An opening 21 having a circular cross section is formed at the center of the valve seat body 20 so as to penetrate the upper chamber 12 and the lower chamber 14 through the vertical direction.

  A valve shaft 22 is provided in the opening closing member 17 of the valve body 15 so as to be movable in the vertical direction so as to penetrate the opening of the valve seat body 20 in the vertical direction. A spherical valve body 23 that opens and closes the opening 21 of the valve seat body 20 by the vertical movement of the valve shaft 22 is provided at the lower end of the valve shaft 22 and below the valve seat body 20. The diameter of the valve body 23 is larger than the diameter of the opening 21. The material of the valve body 23 is preferably selected from steel balls, boron carbide, polyurethane and the like in consideration of wear resistance depending on the type of powder.

  As shown in FIG. 2, the valve body 23 is detachably attached to the valve shaft 22 by a nut 23 a that is screwed onto the valve shaft 22. The valve body 23 is attached to the valve shaft 22 so that the central axis passing through the center of the valve body 23 and the central axis of the valve shaft 22 are coaxial with each other. The part closing member 17 is provided so as to be movable in the vertical direction via a slide bearing 28. The slide bearing 28 is provided in the opening closing member 17 and is disposed above the upper chamber 12. The slide bearing 28 is isolated from the upper chamber 12 by a sealing material 29.

  And between the flange part formed in the upper end of the valve shaft 22, and the upper end surface of the opening part closure member 17, as shown in FIG. 1 thru | or FIG. A spring member 24 is provided to press 23 against the valve seat body 20. The upper end of the valve shaft 22 is fixed to the lower end of the cylinder rod 26 of the cylinder 25 constituting the actuator. The cylinder 25 moves the cylinder rod 26 downward against the urging force of the spring member 24 by an on operation, pushes the valve shaft 22 downward, and releases the force that pushes the valve shaft 22 downward by an off operation. The rod 26 is returned to its original position. Therefore, the valve shaft 22 is moved in the vertical direction by turning on and off the cylinder 25 constituting the actuator.

  The cylinder 25 is provided with a stroke adjusting member (adjusting means) 27 that regulates the downward stroke amount of the cylinder rod 26, that is, adjusts the vertical movement amount of the valve shaft 22. The stroke adjusting member 27 regulates the downward stroke amount of the cylinder rod 26, that is, by adjusting the vertical movement amount of the valve shaft 22, so that the opening 21 of the valve seat body 20 and the spherical valve body 23 are adjusted. The cross-sectional area of the passage formed between the upper chamber 12 and the lower chamber 14 passes through the passage formed between the opening 21 of the valve seat body 20 and the spherical valve body 23. The supply amount of the flowing granular material 40 is adjusted.

Here, the sectional area of the passage will be described with reference to FIG. As shown in FIG. 4A, when the spherical valve body 23 is spaced downward by a distance S with respect to the valve seat body 20, when the diameter of the opening 21 of the valve seat body 20 is D, the valve seat body As shown in FIG. 4B, the cross-sectional area of the passage formed between the 20 openings 21 and the spherical valve body 23 is the area of the hatched portion, and the size thereof is expressed by the following equation. .
Cross-sectional area of the passage B = πD × S
And the supply amount of the granular material 40 which flows into the lower chamber 14 from the upper chamber 12 through the passage formed between the opening 21 of the valve seat body 20 and the spherical valve body 23 is the sectional area of the passage. It is determined by B = πD × S and the pressure difference between the pressure in the upper chamber 12 and the pressure in the lower chamber 14.

Further, the opening area of the inlet 11 provided in the upper chamber 12 is such that the amount of the granular material 40 introduced from the inlet 11 of the upper chamber 12 is such that the granular material 40 falls freely into the upper chamber 12 and The lower chamber passes through a passage formed between the opening 21 of the valve seat body 20 and the spherical valve body 23 regardless of the case where the powder body 40 is pressurized and dropped by the compressed air. 14 is set so as to be larger than the maximum supply amount of the granular material 40 flowing into the gas. Here, the supply amount of the granular material flowing into the lower chamber 14 through the passage formed between the opening 21 of the valve seat body 20 and the spherical valve body 23 is, as described above, the cutting of the passage. It is determined by the area B = πD × S and the pressure difference in the upper chamber 12 and the pressure in the lower chamber 14. The above-mentioned “maximum supply amount” is the difference between the opening 21 of the valve seat body 20 and the valve shaft 22 when the pressure difference between the pressure in the upper chamber and the pressure in the lower chamber is zero (when free-falling). The amount when the amount of powder passing through the cross-sectional area A = π / 4 · (D ² −d ² ) (see FIG. 4 (a)) seen from above the passage formed in the case becomes saturated. Means. Here, D is the diameter of the opening 21 of the valve seat body 20, and d is the diameter of the valve shaft 22.

Specifically, the opening area of the inflow port 11 provided in the upper chamber 12 is preferably set so that the following equation is established.
Opening area of the inlet 11 >> Cross sectional area A = π / 4 · (D ² −d ² ) as viewed from above the passage formed between the opening 21 of the valve seat body 20 and the valve shaft 22
The range in which the supply amount of the granular material flowing into the lower chamber 14 through the passage formed between the opening 21 of the valve seat body 20 and the spherical valve body 23 can be adjusted is the cross-sectional area A = π. / 4 · (D ² −d ² ) ≧ only when the cross-sectional area B = πD × S is satisfied, and when A <B, the supply amount of the granular material is regulated by A, and how much B is large It does not change even if it becomes.

  Further, as shown in FIG. 3, a first pressure outlet 30 is provided in the upper chamber forming member 16 of the valve body 15 to extract the pressure in the upper chamber 12, and the pressure in the lower chamber 14 is applied to the lower chamber forming member 18. A second pressure outlet 31 for taking out is provided. A pressure guiding pipe 32 is connected to the first pressure outlet 30, and a pressure guiding pipe 33 is connected to the second pressure outlet 31. The pressure guiding pipes 32 and 33 are connected to the pressure in the upper chamber 12. A differential pressure gauge 35 for measuring a differential pressure with respect to the pressure in the lower chamber 14 is connected.

  In the air blasting apparatus 1 incorporating such a granular material supply amount variable on-off valve 10, when the granular material 40 is injected from the injection nozzle 5 together with the pressurized air onto the surface of the workpiece, the valve body 23 is the valve seat. While the opening 21 of the body 20 is closed, the compressed air is fed into the mixing tube 3 by the pressurized air supply hose 2, and the pressurized air is fed into the powder storage tank 7 by the pressurized air introduction tube 6. The inside of the body storage tank 7 is pressurized. Thereby, as shown in FIGS. 1 and 2, the granular material 40 stored in the granular material storage tank 7 enters the inlet 11 through the granular material supply pipe 8, and enters the upper chamber 12. As the powder flows down, the powder particles 40 are deposited on the valve seat body 20 in the upper chamber 12. Here, it is not always necessary to pressurize the granular material storage tank 7 by supplying pressurized air to the granular material storage tank 7 through the compressed air introduction pipe 6, and the supply amount of the granular material 40 to the downstream chamber 14 is not necessarily required. In the case where it is sufficient, the granular material 40 may be freely dropped from the granular material storage tank 7 into the upstream chamber 12.

  Next, as shown in FIG. 3, the cylinder 25 is turned on to move the valve shaft 22 downward, and the valve body 23 is opened with respect to the opening 21 of the valve seat body 20. Then, the granular material 40 flows into the lower chamber 14 from the upper chamber 12 through a passage formed between the opening 21 of the valve seat body 20 and the spherical valve body 23. The granular material 40 that has flowed into the lower chamber 14 passes through the outlet 13 and enters the mixing tube 3 from the granular material introduction tube 9.

And the granular material 40 is mixed with the pressurized air supplied from the pressurized air supply hose 2 in the mixing pipe 3, flows into the blast hose 4, and is injected toward the surface of the workpiece from the injection nozzle 5. The
Here, according to the granular material supply amount variable on-off valve 10 and the air blast device 1 according to the present embodiment, the stroke amount of the cylinder rod 26 is regulated by the stroke adjusting member 27, that is, the valve shaft. By adjusting the amount of movement of the valve 22 in the vertical direction, the size of the cross-sectional area of the passage formed between the opening 21 of the valve seat body 20 and the spherical valve body 23 is adjusted, and the opening of the valve seat body 20 is adjusted. The supply amount of the granular material 40 flowing from the upper chamber 12 into the lower chamber 14 through the passage formed between the valve 21 and the spherical valve body 23 can be adjusted. For this reason, the supply amount of the granular material 40 can be continuously changed by adjusting the size of the cross-sectional area of the passage formed between the opening 21 of the valve seat body 20 and the valve body 23. Then, by adjusting the amount of movement of the valve shaft 22 in the vertical direction, the size of the cross-sectional area of the passage formed between the opening 21 of the valve seat body 20 and the spherical valve body 23 can be adjusted. The opening degree of the body 23 can be easily adjusted.

  Then, the lower chamber 14 having the outlet 13 from which the compressed air and the granular material flow out is provided to the upper chamber 12 having the inlet 11 into which the compressed air and the granular material 40 flow from the granular material storage chamber 7. It is provided below in the vertical direction. Further, a valve seat body 20 having an opening 21 having a circular cross-section that penetrates in the vertical direction and communicates with the upper chamber 12 and the lower chamber 14 is provided so as to separate the upper chamber 12 and the lower chamber 14. A valve shaft 22 is provided so as to be vertically movable with respect to the valve body 15 so as to penetrate the opening 21 in the vertical direction, and a spherical valve that opens and closes the opening 21 of the valve seat body 20 by moving the valve shaft 22 in the vertical direction. The body 23 is provided at the lower end of the valve shaft 22 and below the valve seat body 20. Thereby, since the valve body 23 is arranged below the valve seat body 20 and in the direction of gravity, the powder body 40 is in a diffusive drop state regardless of whether it is a free fall or a pressure drop. The amount of the granular material 40 that flows down to the opening 21 and flows into the lower chamber 14 from the upper chamber 12 through the passage formed between the opening 21 of the valve seat body 20 and the spherical valve body 23 is stabilized. Can be made. Thereby, the supply amount of the granular material 40 in the adjusted cross-sectional area of the passage can be continuously stabilized with high accuracy without variation, and the granular material with improved reproducibility accuracy of the supply amount of the granular material 40 The supply amount variable on-off valve 10 and the air blast device 1 can be provided.

Here, since the valve body 23 is formed in a spherical shape, it is possible to avoid the inconvenience that the valve body 23 cannot be removed from the opening 21 like a conical valve body.
Further, when the valve body 23 is disposed above the valve seat body 20, the valve body 23 opens from the closed state as shown in FIG. 6A and the valve body 23 as shown in FIG. 6B. There are the following inconveniences for each case of closing from the open state.

  First, when the valve body 23 shown in FIG. 6 (a) is opened from the closed state, the self-weight direction of the particulate 40 is different from the operation direction (from the bottom to the top) of the valve shaft 22, and the valve shaft 22 is pushed up. A force for pushing up the granular material 40 supplied to the upper chamber 12 by the valve body 23 is required, the operating force of the valve shaft 22 is increased, the responsiveness of the valve body 23 is deteriorated, and the mechanism for operating the valve shaft 22 Problems such as increase in size.

  Further, when the valve body 23 shown in FIG. 6B is closed from the open state, the operation direction of the valve shaft 22 is downward from the top, and the valve body 23 pushes the granular material 40 around the lower side of the valve body 23. Since it hardens, time and a large force are required until the valve body 23 is closed, the operating force of the valve shaft 22 is increased, the responsiveness of the valve body 23 is deteriorated, and a mechanism for operating the valve shaft 22 is provided. Problems such as an increase in size arise.

  On the other hand, in the granular material supply amount variable on-off valve 10 according to the present embodiment, the valve body 23 is disposed below the valve seat body 20, so that when the valve body 23 opens from the closed state, The self-weight direction of the granular material 40 and the operation direction (from the top to the bottom) of the valve shaft 22 are the same, and the operation force of the valve shaft 22 can be small. For this reason, the responsiveness of the valve body 23 is good, and problems such as an increase in the size of the mechanism for operating the valve shaft 22 do not occur.

  Moreover, in the granular material supply amount variable on-off valve 10 according to the present embodiment, the valve body 23 is disposed below the valve seat body 20, and therefore, when the valve body 23 is closed from the open state, the valve shaft 22. Therefore, the valve body 23 does not cause the powder body 40 to be pressed and solidified from the bottom to the top, and time and a large force are not required until the valve body 23 is closed, and the operation force of the valve shaft 22 is small. For this reason, the responsiveness of the valve body 23 is good, and problems such as an increase in the size of the mechanism for operating the valve shaft 22 do not occur.

  And in the granular material supply amount variable on-off valve 10 according to the present embodiment, the amount of the granular material 40 introduced from the inflow port 11 of the upper chamber 12 corresponds to the case where the granular material 40 falls freely and the powder The lower chamber 14 passes through a passage formed between the opening 21 of the valve seat body 20 and the spherical valve body 23, regardless of the case where the granular body 40 is pressurized and dropped by the compressed air. The opening area of the inflow port 11 is set so as to be larger than the maximum supply amount of the granular material 40 flowing into the. For this reason, in any case where the granular material 40 falls freely and when the granular material 40 is pressurized and dropped by the pressurized air, the valve body 23 is in contact with the opening 21 of the valve seat body 20. In any of the opened and closed states, the granular material 40 always accumulates above the valve seat body 20 in the upper chamber 12, and the granular material 40 is evenly and circumferentially in the opening 21 of the valve seat body 20. Will be deposited. For this reason, the supply amount of the granular material 40 flowing into the lower chamber 14 from the upper chamber 12 through the passage formed between the opening 21 of the valve seat body 20 and the spherical valve body 23 can be stabilized. it can. Thereby, the supply amount of the granular material 40 in the adjusted cross-sectional area of the passage can be continuously stabilized with high accuracy without variation, and the granular material with improved reproducibility accuracy of the supply amount of the granular material 40 The supply amount variable on-off valve 10 and the air blast device 1 can be provided.

  Moreover, according to the granular material supply amount variable on-off valve 10 according to the present embodiment, the valve body 23 is connected to the valve shaft 22 with a central axis passing through the center of the valve body 23 and a central axis of the valve shaft 22. Are attached so as to be coaxial with each other, and the valve shaft 22 is provided so as to be movable in the vertical direction with respect to the valve body 15 via a slide bearing 28. For this reason, it is possible to avoid the eccentricity of the valve body 23 with respect to the opening 21 of the valve seat body 20. Thereby, the cross-sectional area of the channel | path formed between the opening 21 of the valve seat body 20 and the spherical valve body 23 becomes equal, and the precision of the reproducibility of the supply amount of the granular material 40 can be improved.

  Furthermore, according to the granular material supply variable open / close valve 10 according to the present embodiment, the slide bearing 28 is disposed above the upper chamber 12 in the valve body 15, and the slide bearing 28 is sealed against the upper chamber 12. It is isolated by the material 29. For this reason, the granular material 40 does not contact the slide bearing 28, the biting of the granular material 40 can be avoided, and the wear of the valve shaft 22 due to the biting of the granular material 40 can be avoided. The shaft 22 can move smoothly.

  Furthermore, according to the granular material supply amount variable on-off valve 10 according to the present embodiment, the spring member 24 that urges the valve shaft 22 upward and presses the valve body 23 against the valve seat body 20 and the spring by the on operation. And a cylinder (actuator) 25 that releases the force that pushes down the valve shaft 22 against an urging force of the member 24 and releases the valve shaft 22 downward by an off operation. Move up and down. Therefore, the valve shaft 22 can be moved up and down, that is, the valve body 23 can be opened and closed with a simple configuration.

Further, in the granular material supply variable open / close valve 10 according to the present embodiment, the mass of the granular material 40 is W, the pressure in the upper chamber 12 at the time of inflow of compressed air is P3, and the lower chamber at the time of inflow of compressed air 14 is P4, the cross-sectional area of the opening 21 is A, the pressing force by the cylinder (actuator) 25 is Fa, and the urging force of the spring member 24 upward of the valve shaft 22 is Fs, the following (1) The mass W of the granular material 40, the pressure P3 in the upper chamber 12 at the time of inflow of compressed air, the pressure P4 in the lower chamber 14 at the time of inflow of compressed air, the cross-sectional area A of the opening 21, It is preferable to set the pressing force Fa by the cylinder 25 and the urging force Fs upward of the valve shaft 22 by the spring member 24.
Fa >> Fs >> (A × (P3-P4) + W) (1)

As a result, the upward biasing force Fs of the valve shaft 22 by the spring member 24 is greater than the force obtained by adding the mass of the compressed air and the granular material 40, so that the position of the valve body 23 relative to the valve seat body 20 also due to disturbance. The supply amount of the granular material 40 flowing into the lower chamber 14 from the upper chamber 12 through the passage formed between the opening 21 of the valve seat body 20 and the spherical valve body 23 is stabilized without changing Can be made. Further, since the pushing force Fa by the cylinder (actuator) 25 is larger than the force Fa exerted by the spring member 24 on the valve shaft 22, the passage is reliably formed.
Further, as shown in FIG. 5, the pressure in the pressurized air supply hose 2 at the time of feeding the pressurized air is P1, the pressure in the granular material storage tank is P2, the pressure in the upper chamber 12 is P3, and the pressure in the lower chamber 14 It is preferable to set the respective pressures so that P1>P2>P3>P4> P5 is established, where P4 is the pressure of P4 and P5 is the pressure in the mixing tube 3.

In particular, it is preferable to set the pressure P3 in the upper chamber 12 at the time of inflow of compressed air and the pressure P4 in the lower chamber 14 at the time of inflow of compressed air so that the following equation (2) is satisfied.
P3> P4 (2)
Thereby, the pressure P3 in the upper chamber 12 at the time of inflow of compressed air is set larger than the pressure P4 in the lower chamber at the time of inflow of compressed air, and the opening 21 of the valve seat body 12 and the spherical valve body 23 The supply amount of the granular material 40 flowing from the upper chamber 12 into the lower chamber 14 through the passage formed therebetween can be stabilized.

  Furthermore, according to the granular material supply amount variable on-off valve 10 according to the present embodiment, the valve body 15 is provided with the first pressure extraction port 30 for extracting the pressure in the upper chamber 12 and the pressure in the lower chamber 14. A second pressure outlet 31 was provided. For this reason, by detecting the differential pressure between the pressure in the upper chamber taken out from the first pressure outlet 30 and the pressure in the lower chamber taken out from the second pressure outlet 31, and controlling the differential pressure, The supply amount of the granular material 40 flowing from the upper chamber 12 into the lower chamber 14 through the passage formed between the opening of the valve seat body and the spherical valve body can be further stabilized.

  Further, according to the granular material supply variable open / close valve 10 according to the present embodiment, the lower chamber forming member 18 and the bottom member 19 (portion forming the lower chamber) of the valve body 15 are transparent members (transparent Resin member). For this reason, the flow-down state of the granular material 40 flowing into the lower chamber 14 from the upper chamber 12 through the passage formed between the opening 21 of the valve seat body 20 and the spherical valve body 23 is observed from the outside. Can do.

  Further, according to the granular material supply variable open / close valve 10 according to the present embodiment, the valve seat body 20 is detachably attached to the valve body 15 and the valve body 23 is detachably attached to the valve shaft 22. . For this reason, when the valve seat body 20 or the valve body 23 is worn away, the valve seat body 20 or the valve body 23 is detached from the valve body 15 or the valve shaft 22 and inverted, and is attached to the valve body 15 or the valve shaft 22 again. It can be restored, the durability of each can be doubled, and the running cost can be reduced.

As mentioned above, although embodiment of this invention has been described, this invention is not limited to this, A various change and improvement can be performed.
For example, the powder supply amount variable on-off valve 10 has been described for the case where it is incorporated in the air blast device 1, but not only when it is incorporated in the air blast device 1, but also the particles from the granule storage tank. The present invention can be applied to other powder / granule supply amount variable on-off valves used when supplying to the injection nozzle.

  The opening degree of the valve body 23 (distance S at which the valve body 23 is separated from the valve seat body 20, see FIG. 4) is set to 3 mm, 4 mm, and 5 mm, and the granular material 40 is opened from the opening 21 (opening diameter: 24 mm) to the lower chamber. The amount of fall of the granular material 40 when it was made to fall freely to 14 (pressurization pressure: 0 KPa) and when making it fall under pressure was investigated. The results are shown in Table 1. In addition, the valve body 23 used the thing with a diameter of 25.4 mm, and used the melanin resin whose particle size is 70 micrometers-180 micrometers as the granular material 40. FIG.

When the granular material 40 is freely dropped from the opening 21 to the lower chamber 14, the variation rate of the amount of dropping of the granular material 40 is 0.81% when the valve opening is 3 mm, and the valve opening is 4 mm. In this case, the variation was 1.50%, and when the valve opening was 5 mm, the variation was 0.77%, and the variation was very small.
Further, when the granular material 40 is pressure-dropped from the opening 21 to the lower chamber 14, the variation rate of the dropping amount of the granular material 40 is 1.59% when the valve opening is 3 mm, and the valve opening Is 2.30% in the case of 4 mm, and 1.06% in the case of the valve opening degree of 5 mm, and the variation is larger but smaller than in the case of free fall.
In addition, the ratio of the average fall amount B when the granular material 40 is freely dropped to the average fall amount A when it is freely dropped is 3.53 when the valve opening is 3 mm, and the valve opening is 4 mm. It can be seen from Table 1 that the variation in the amount of powder fall between the cases where the valve opening degree is 3.47 and the valve opening degree is 5.45 is 3.45, and the amount of powder falling between the different valve opening degrees can be very small.

DESCRIPTION OF SYMBOLS 1 Air blasting device 2 Pumping air supply hose 3 Mixing pipe 4 Blasting hose 5 Injection nozzle 6 Pumping air introduction pipe 7 Powder storage tank 8 Powder supply pipe 9 Powder supply pipe 9 Powder supply amount variable opening and closing type Valve 11 Inlet 12 Upper chamber 13 Outlet 14 Lower chamber 15 Valve body 16 Upper chamber forming member 17 Opening block member 18 Lower chamber forming member 19 Bottom member 20 Valve seat body 21 Opening 22 Valve shaft 23 Valve body 24 Spring member 25 Cylinder (actuator)
26 Cylinder rod 27 Stroke adjustment member (Adjustment means)
28 Thrust bearing 29 Seal member 30 First pressure outlet 31 Second pressure outlet 32, 33 Pressure guiding pipe 35 Differential pressure gauge

Claims (10)

A granular material supply amount variable on-off valve used when supplying the granular material from the granular material storage tank to the injection nozzle,
An upper chamber having an inflow port through which the compressed air and the granular material from the granular material storage chamber flow in, and an outflow port provided vertically below the upper chamber and through which the compressed air and the granular material flow out. A valve body comprising a lower chamber having;
A valve seat body provided in the valve main body so as to separate the upper chamber and the lower chamber, and having an opening having a circular cross section penetrating in the vertical direction and communicating the upper chamber and the lower chamber;
A valve shaft that is vertically movable with respect to the valve body so as to penetrate the opening of the valve seat body in the vertical direction;
A spherical valve body that is provided at a lower end of the valve shaft and below the valve seat body, and opens and closes an opening of the valve seat body by moving the valve shaft in a vertical direction;
By adjusting the amount of movement of the valve shaft in the vertical direction, the size of the cross-sectional area of the passage formed between the opening of the valve seat body and the spherical valve body is adjusted, and the opening of the valve seat body And adjusting means for adjusting the supply amount of the granular material flowing from the upper chamber into the lower chamber through a passage formed between the spherical valve body,
Regardless of the case where the amount of the granular material charged from the inlet of the upper chamber is either the case where the granular material falls freely or the case where the granular material falls by being pressurized by pressurized air The opening area of the inlet so as to be larger than the maximum supply amount of the granular material flowing into the lower chamber through a passage formed between the opening of the valve seat body and the spherical valve body A granular material supply amount variable on-off valve, characterized by setting.   The valve body is attached to the valve shaft so that a central axis passing through the center of the valve body and a central axis of the valve shaft are coaxial with each other, and the valve shaft is slidably bearing with respect to the valve body. 2. The granular material supply amount variable on-off valve according to claim 1, wherein the on-off valve is provided so as to be movable in the vertical direction.   3. The supply amount of granular material according to claim 2, wherein the slide bearing is disposed above the upper chamber in the valve body, and the slide bearing is isolated from the upper chamber by a sealing material. Open / close valve.   A spring member that urges the valve shaft upward to press the valve body against the valve seat body; and an on operation that pushes the valve shaft downward against an urging force of the spring member; An actuator for releasing a force that pushes down the shaft downward, and the valve shaft is moved in the up-down direction by an on / off operation of the actuator, and the powder according to any one of claims 1 to 3 Body supply variable opening / closing valve. The mass of the granular material is W, the pressure in the upper chamber at the time of inflow of compressed air is P3, the pressure in the lower chamber at the time of inflow of compressed air is P4, the sectional area of the opening is A, and the actuator When the pressing force is Fa and the upward biasing force of the valve shaft by the spring member is Fs, the mass W of the granular material, the inflow of the compressed air, so that the following expression (1) is satisfied. The pressure P3 in the upper chamber, the pressure P4 in the lower chamber at the time of inflow of pumped air, the sectional area of the opening A, the pressing force Fa by the actuator, and the biasing force Fs upward of the valve shaft by the spring member The granular material supply amount variable on-off valve according to claim 4, wherein the on-off valve is set.
Fa >> Fs >> (A × (P3-P4) + W) (1) 6. The pressure P3 in the upper chamber at the time of inflow of compressed air and the pressure P4 in the lower chamber at the time of inflow of compressed air are set so that the following equation (2) is satisfied. Open / close valve with variable powder supply.
P3> P4 (2)   7. The valve body according to claim 1, further comprising: a first pressure extraction port for extracting pressure in the upper chamber; and a second pressure extraction port for extracting pressure in the lower chamber. The granular material supply amount variable on-off valve according to claim 1.   The part which forms a lower chamber among the said valve bodies is formed with the transparent member, The granular material supply amount variable type on-off valve as described in any one of Claims 1 thru | or 7 characterized by the above-mentioned.   The powder granule according to any one of claims 1 to 8, wherein the valve seat body is detachably attached to the valve body, and the valve body is detachably attached to the valve shaft. Body supply variable opening / closing valve.   The inlet of the upper chamber of the granular material supply amount variable on-off valve according to any one of claims 1 to 9, is connected to the granular material storage tank via a granular material supply pipe, The outlet of the lower chamber of the particulate supply amount variable on-off valve is connected to a mixing tube having one end connected to a pressure air supply hose and the other end connected to a blast hose having the injection nozzle. A featured air blasting device.

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