JP2005081365A - Powder feeder of dry type isotropic pressing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mechanism capable of detecting a filled state of raw powder in a shaping rubber mold without degradation of productivity in a short time and ensuring consistent feed of raw powder when the raw powder is fed into the shaping rubber mold of a dry type isotropic pressing device. <P>SOLUTION: In the powder feeder of the dry type isotropic pressing device having a tubular powder-feed nozzle to feed raw powder from an upper part on a shaping rubber mold, the powder feed nozzle 1 is bent in the middle thereof so that a powder feed unit 1a on a raw powder metering and feeding device 8 side is in a diagonal direction, and an elevating/lowering cylinder sensor 2 having a flat sensor unit 6 on a tip of a piston rod 2a is mounted on a portion 1c formed by the bend and facing an upper end face U of raw powder P fed to the shaping rubber mold 5. The level of the upper end face U of the metered raw powder P in the shaping rubber mold 5 can be detected by the contact of the sensor unit 6 in the metering and feeding device 8, and the raw powder P can be adequately fed into the shaping rubber mold 5. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a powder feeding device that feeds raw material powder into a molding rubber mold of a dry isotropic pressure pressurization device (dry CIP device), and more specifically, a feeding device equipped with a mechanism for detecting the quantitative supply of the raw material powder. It relates to a powder device.

  For example, a powder feeding device shown in FIG. 5 is disclosed as a powder feeding device for supplying raw material powders such as ceramics and carbon to a molded rubber mold with a dry isotropic pressure device (see Patent Document 1). The powder supply nozzle 21 of this powder supply apparatus is composed of a metal powder supply pipe 22, a vent pipe 23 concentrically provided on the outside thereof, and a synthetic rubber ring-shaped packing 24. An exhaust port 25 is provided above. An attachment screw for a powdering hose 26 is formed on the outer peripheral surface of the upper end portion of the powdering pipe 22 which is formed thick, and this powdering hose 26 is connected to the powdering pipe 22 at one end side and the other end. On the side, the raw material powder P is communicated with a supply source of the raw material powder P through a raw material powder quantitative supply device (not shown). Further, the lower surface of the thick wall portion of the powder feeding tube 22 and the upper end surface of the ventilation pipe 23 are welded in the circumferential direction, and a gap is formed between the powder feeding pipe 22 and the ventilation pipe 23 so that gas can freely flow. The powder feed nozzle 21 has a double tube structure in which the gas flowing through the gap is discharged only from the exhaust port 25. The powder feed nozzle 21 is inserted into the opening 27 a of the upper lid 27 of the high pressure container of the dry isotropic pressure pressurizing unit, and the taper taper portion of the packing 24 provided around the lower end thereof is inserted into the upper end of the molded rubber mold 28. The high pressure vessel is mounted in contact with the peripheral surface.

Japanese Utility Model Publication No. 64-42799

  When the raw material powder P is supplied into the molding rubber mold 28 in which the lower punch 29 of the dry isotropic pressure pressurizer is incorporated using the powder feeding nozzle 21, the supply powder is filled into the molding rubber mold 28. Accordingly, the gas flowing in with the supply powder and the gas in the molding rubber mold 28 flow out from the exhaust port 25 through the flow path indicated by the arrow. The raw material powder that rises accompanying this air flow does not accumulate on the upper end surface of the molding rubber mold 28, and the outflowing gas flows out only from the exhaust port 25, so the outflow accompanies this gas. This makes it easy to capture and collect the raw material powder, and to solve the conventional problems such as hindering continuous operation.

  However, in the above-mentioned powder feeding device, the supply amount of the raw material powder P is controlled by weight measurement or volumetric measurement in the raw material powder quantitative supply device, but the actual state in which the raw material powder is put into the molded rubber mold 28 That is, no mechanism for detecting the upper surface level (upper end surface) of the raw material powder P in the molded rubber mold 28 is provided. For this reason, there is a problem that even if the metering by the raw material powder quantitative supply device is normal, the stable supply of the raw material powder P to the molded rubber mold 28 cannot be finally guaranteed before the pressure molding. Further, the detection of the upper end surface of the raw material powder P supplied to the molding rubber mold 28, that is, the filling state, needs to be performed in a short time in order not to reduce the productivity.

  Accordingly, the problem of the present invention is that when the raw powder is supplied into the molding rubber mold of the dry isostatic pressing apparatus, the filling state of the raw powder in the molding rubber mold is reduced for a short time without reducing the productivity. It is possible to provide a mechanism that can detect and guarantee a stable supply of raw material powder.

  In order to solve the above problems, the present invention employs the following configuration.

  That is, in a powder feeding device of a dry isotropic pressure pressurizer equipped with a tubular powder feeding nozzle for supplying raw material powder from above to a molded rubber mold, the raw material filled in the molded rubber mold in the powder feeding nozzle The powder level detecting means for detecting the position of the upper end surface of the powder is provided so that the sensor part faces the upper end surface of the raw material powder.

  In this way, it is possible to detect the actual upper end surface of the raw material powder supplied into the molded rubber mold, that is, the powder surface. In addition, it is possible to prevent defective molding due to clogging in the molded rubber mold of the molded product after pressure molding due to excessive amount of raw material powder, and furthermore, shape defects due to excessive and excessive amount of raw material powder. Will improve. In addition, since the powder level detection means is a mechanism provided in the powder feed nozzle, the time required for powder level detection is very short, the loss of molding cycle time can be minimized, and productivity is not hindered. .

  It is desirable that the powder level detecting means is formed so as to detect the position of the upper end surface when the tip of the piston rod of the elevating cylinder comes into contact with the upper end surface of the raw material powder.

  In this way, based on the stroke amount (displacement) of the piston rod, the upper end surface (powder surface) of the raw material powder supplied into the molded rubber mold can be easily detected.

  A concave annular portion is provided at the distal end of the piston rod, and the lower end of the annular side wall of the annular portion is accommodated in the concave portion of the concave annular portion by accommodating the distal end portion of the mandrel arranged concentrically with the molding rubber mold. The position of the upper end surface can also be detected by contacting the upper end surface of the raw material powder.

In this way, even when the mandrel is placed concentrically in the molded rubber mold and pressure-molded into a pipe-shaped molded body, the tip of the mandrel that protrudes from the upper end surface of the raw material powder filled in the mold Therefore, the lower surface of the annular side wall of the concave annular portion can be brought into contact with the upper end surface of the raw material powder without obstructing the tip of the protruding mandrel.

  A non-contact distance sensor can also be used as the powder level detecting means.

  The position of the upper end face in the molded rubber mold can also be detected by measuring the distance to the upper end face of the raw material powder by a non-contact type distance sensor such as a laser type or an ultrasonic type. The non-contact type distance sensor eliminates the risk of malfunction as compared with the contact type sensor such as when the lifting cylinder is used.

  The powder supply nozzle is bent in the middle so that the supply end side of the raw material powder is in an oblique direction, and the powder supply is opposed to the upper end surface of the raw material powder filled in the molded rubber mold by this bending. It is desirable to provide the powder level detecting means at the nozzle portion.

  In this way, the powder level detecting means can be easily attached to the powder feed nozzle so as to face the upper end surface of the raw material powder filled in the molding rubber mold, The position can be detected in a very short time.

  It is desirable to provide means for controlling the supply amount of the raw material powder to the powder feed nozzle based on the position of the upper end surface of the raw material powder detected by the powder level detection means.

  As described above, the optimum powder supply condition can be automatically set by feeding back the position detection result of the upper end surface of the raw material powder to the supply side.

  According to the present invention, not only a solid molded body but also a hollow molded body is pressure-molded by using a contact-type or non-contact-type sensor provided in a powder feeding nozzle of a dry isotropic pressure pressurizing device. Since the position of the upper end surface of the raw material powder supplied into the molding rubber mold is actually detected, an appropriate amount of the raw material powder is pressure-molded while being supplied and filled in the molding rubber mold. Thereby, the trouble in shaping | molding by the raw material powder being insufficient or excessive can be eliminated, and the quality of a molded object can be improved.

  Further, since the contact type or non-contact type sensor is provided in a portion that is opposed to the upper end surface of the raw material powder filled in the molded rubber mold by bending the powder feeding nozzle in the middle thereof, It can be easily attached to the powder feed nozzle, and the position of the upper end surface of the raw material powder can be detected in a very short time. Thereby, loss of molding cycle time can be minimized and productivity is not hindered.

  Furthermore, since the position detection result of the upper end surface of the raw material powder is fed back to the supply side, the optimum powder supply condition can be automatically set.

  Embodiments of the present invention will be described below with reference to the accompanying FIGS.

  FIG. 1 shows a powder feeder of the dry isostatic pressurizer of the first embodiment. This powder feeder is arranged so that the powder feed section 1a on the feed end side of the raw material powder is in an oblique direction. Bending powder supply nozzle 1, elevating cylinder sensor 2 which is a contact-type powder level detection means, vent pipe 3 provided concentrically on the outer periphery of the feed portion 1b of the raw material powder P of the powder supply nozzle 1, and tip An exhaust port 3 a is provided in the upper part of the vent pipe 3. The raising / lowering cylinder sensor 2 is perpendicular to the attachment site 1c of the powder feeding nozzle 1 which is opposed to the upper end surface U (powder surface) of the raw material powder P filled in the molding rubber mold 5 by bending of the powder feeding nozzle 1. A flat sensor portion 6 is provided at the tip of the piston rod 2a so as to be in contact with the raw material powder P, that is, in surface contact with the upper end surface U. The powder supply unit 1 a is connected to a raw material powder metering device 8 through a powder supply hose 7. A linear displacement sensor 9 for detecting the position of the upper end surface U (powder surface) of the raw material powder P in the molding rubber mold 5 is attached to the lifting cylinder sensor 2. In addition, as for the said sensor part 6, it is desirable to enlarge the contact surface 6a as much as possible, and to enlarge the contact area with the raw material powder P. FIG. The powder feed nozzle 1 does not have a double-pipe structure of the charging part 1b and the ventilation pipe 3, but a single-pipe structure so that the ventilation pipe 3 provided with the exhaust port 3a also serves as the charging part of the raw material powder P. It may be.

  In the raw material powder metering device 8, the raw material powder P weighed to a preset weight or volume is supplied from the powder feed nozzle 1 through the powder feed hose 7 and filled in the molded rubber mold 5. After filling, the piston rod 2a of the elevating cylinder sensor 2 moves forward as indicated by the broken line, and the sensor unit 6 provided at the tip thereof descends, and this sensor unit 6 is the upper end surface U (powder surface) of the raw material powder P. The forward movement of the piston rod 2a stops due to the contact resistance. The amount of advancement of the piston rod 2a at this time is measured by the linear displacement sensor 9, and the position of the upper end surface U (powder surface) of the raw material powder P in the molding rubber mold 5 is detected based on the measured value. Whether or not the position detection value falls within a preset appropriate position range is compared by a comparator (not shown) connected to the linear displacement sensor 9.

  When the position detection value falls within the appropriate position range, the piston rod 2a moves backward, the sensor unit 6 rises from the state indicated by the broken line, and returns to the initial position as indicated by the solid line. Thereafter, the powder feed nozzle 1 moves together with the lift cylinder sensor 2 from the upper part of the molding rubber mold 5 and retracts, and an upper punch for molding, not shown, enters the upper part of the molding rubber mold 5 to form the molding rubber mold 5. The raw material powder P is pre-pressurized with a lower punch for molding (not shown) incorporated in the lower part of the mold, and isotropic pressure is applied radially from the outer periphery of the molded rubber mold 5 to perform dry CIP molding. On the other hand, when the position detection value is excessively supplied out of the proper position range, an alarm is generated by an alarm device (not shown) connected to the comparator, and an abnormality is notified before dry CIP molding. In case of undersupply, the shortage is calculated and additional supply is performed.

  The lift cylinder sensor 2 is provided with a mechanism that can greatly reduce the downward thrust because the piston rod 2a needs to stop moving forward due to the powder surface resistance of the upper end surface U (powder surface) of the raw material powder P. ing. In addition, as a driving method, any of fluid pressure driving such as air pressure and hydraulic pressure, and electric driving can be used. As a mechanism that can greatly reduce the descending thrust, a mechanism that incorporates a flow rate adjusting valve in a pneumatic circuit or hydraulic circuit that drives the ascending / descending cylinder sensor 2, and a spring in the cylinder of the ascending / descending cylinder sensor 2 to reduce the descending thrust An additional mechanism can be employed. Furthermore, a mechanism for adding a weight considering the sliding resistance between the inner wall of the cylinder and the piston head and dropping the piston rod 2a by its own weight, or a mechanism for adding a spring instead of the weight and utilizing the repulsive force It is also possible to adopt.

  If the powder feeding device of the dry isotropic pressure pressurizing device is configured as described above, it is possible to prevent the shape defect due to the excessive or excessive amount of the raw material powder P, and the lifting cylinder sensor 2 is provided in the powder feeding nozzle 1. Therefore, the time required for detecting the powder surface is very short, and the quality of the molded product can be improved by the appropriate amount of raw material powder without impairing the productivity.

  FIG. 2 shows a second embodiment. The program controller 10 connected to the linear displacement sensor 9 calculates the difference between the position detection value and the appropriate value of the powder surface position set in advance of the raw material powder. It is converted into a supply correction amount, and this supply correction amount is fed back to the raw material powder metering device 8, so that the supply amount of the raw material powder to the molding rubber mold 5 is automatically corrected. In this way, since the supply amount is automatically corrected to the molding rubber mold 5, it is not necessary to waste time in setting up the raw material powder supply, improving productivity and improving the raw material powder supply process. Unmanned.

  FIG. 3 shows a third embodiment. A concave annular sensor is used instead of the flat sensor portion 6 shown in FIGS. 1 and 2 at the tip of the piston rod 2a of the elevating cylinder sensor 2. FIG. A concave annular portion 11 is provided. In this way, even when the mandrel 12 is disposed concentrically in the molded rubber mold 5 and pressure-molded into a pipe-shaped molded body, the upper end surface U (powder surface) of the raw material powder P filled in the mold ) Can be accommodated in the recess 11a of the concave annular portion 11, so that the protruding tip 12a of the mandrel 12 does not become an obstacle, and the lower surface 11b of the annular side wall of the concave annular portion 11 is not obstructed. Can be brought into contact with the upper end surface U (powder surface) of the raw material powder P. Thereby, also when a molded object is pipe shape, the raising / lowering cylinder sensor 2 can be used for a powder surface position detection, and an application object is expanded. Also in this embodiment, feedback control for correcting the supply amount of the raw material powder P shown in FIG. 2 can be performed.

  FIG. 4 shows a fourth embodiment. Instead of using a contact-type sensor such as the lifting cylinder sensor 2 shown in FIGS. 1 to 3 as the powder level detection means, a laser type or ultrasonic type is used. A non-contact type distance sensor 13 such as is mounted in a vertical direction on a portion 1c of the powder feeding nozzle 1 facing the upper end surface U (powder surface) of the raw material powder P filled in the molding rubber mold 5. If such a non-contact type distance sensor 13 is used, since there is no mechanical elevation of the sensor unit 6 as in the case of the elevation cylinder sensor 2 shown in FIG. 1 to FIG. No mechanical malfunction occurs. Even when this non-contact type distance sensor 13 is used, the program controller 10a is provided in the same manner as shown in FIG. 2 to compare the position detection value with the preset appropriate value of the powder surface position. Based on the difference, the feed correction amount can be feedback controlled to the raw material powder metering device 8.

  Used to detect the appropriate supply amount of the raw material powder into the molded rubber mold and automatically correct the supply amount when pressure-molding powders of ceramics, carbon, etc. with a dry isostatic pressing device (dry CIP device) And the reliability of the powder feeder is improved.

Longitudinal front view of a powder feeding apparatus provided with contact-type powder level detection means of the first embodiment of the present invention Longitudinal front view of a powder feeding apparatus provided with a powder amount control means of the second embodiment Longitudinal front view of a powder feeding apparatus provided with contact-type powder level detection means of the third embodiment Longitudinal front view of the powder feeding apparatus provided with the non-contact type powder level detecting means of the fourth embodiment Longitudinal front view of conventional powder feeder

Explanation of symbols

1: Powdering nozzle 1a: Powdering part 1b: Input part 1c: Mounting part 2: Lift cylinder sensor 2a: Piston rod 3: Vent pipe 3a: Exhaust port 4: Tip seal member 5: Molded rubber mold 6: Sensor part 6a : Contact surface 7: Powder supply hose 8: Raw material powder metering device 9: Linear displacement sensor 10 and 10a: Program controller 11: Concave annular part 11a: Concave part 11b: Underside of annular side wall 12: Mandrel 12a: Tip part 13: Distance sensor P: Raw material powder U: Upper end surface

Claims (6)

In a powder feeder of a dry isotropic pressure pressurizer equipped with a tubular powder feed nozzle that feeds raw powder from above into a molded rubber mold, the powder feed nozzle is filled with a raw powder filled in the molded rubber mold. A powder feeding device for a dry isotropic pressure pressurizing device, characterized in that powder level detecting means for detecting the position of the upper end surface is provided so that the sensor portion faces the upper end surface of the raw material powder. The said powder level detection means is formed so that the position of the said upper end surface may be detected when the front-end | tip part of the piston rod of a raising / lowering cylinder contacts the upper end surface of raw material powder. Drying device for dry isostatic pressurizer. A concave annular portion is provided at the distal end of the piston rod, and the lower surface of the annular side wall of the annular portion is accommodated in the concave portion of the concave annular portion by accommodating the distal end portion of the mandrel disposed concentrically with the molded rubber mold. The powder feeding device of the dry isostatic pressurizing device according to claim 2, wherein the powder is brought into contact with the upper end surface of the raw material powder. The powder feeding device of the dry isotropic pressure pressurizing device according to claim 1, wherein the powder level detecting means is a non-contact type distance sensor. The powder supply nozzle is bent in the middle so that the supply end side of the raw material powder is in an oblique direction, and the powder supply is opposed to the upper end surface of the raw material powder filled in the molded rubber mold by this bending. The powder supply device of the dry isotropic pressure pressurizing device according to any one of claims 1 to 4, wherein the powder level detecting means is provided at a nozzle portion. The means for controlling the supply amount of the raw material powder to the powder feed nozzle is provided based on the position of the upper end surface of the raw material powder detected by the powder level detection means. The powder feeder of the dry isostatic pressurizer described in 1.

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