JP6020817B2 - Metal powder molding system - Google Patents

Description

  The present invention relates to a metal powder molding system for molding metal powder such as rare earth alloy magnetic powder.

  FIG. 3 is an illustrative process diagram from molding of the rare earth alloy magnetic powder to loading of the molded body onto the tray. First, as shown in FIG. 3A, a predetermined amount of molding material 26 (rare earth alloy magnetic powder) is filled into a cavity formed by a die 27 (mortar) and a lower punch 28 of a molding die. Then, as shown in FIG. 3B, the molding material 25 is obtained by pressurizing the molding material 26 with the upper punch 29 and the lower punch 28 while applying a magnetic field by the electromagnet 30 and molding in the magnetic field. Thereafter, the molded body 25 is extracted as shown in FIG. 3C, and the molded body 25 is held by the take-out clamp 4 as shown in FIG. Then, as shown in FIG. 3E, an alternating magnetic field (damped oscillating magnetic field) is applied to the molded body 25 held by the take-off clamp 4 by the deburring coil 7 to demagnetize the air, and air is discharged from the nozzle 22. The magnetic powder adhered to the surface of the molded body 25 is removed by spraying. Finally, as shown in FIG. 3F, the loading robot 20 accommodates the molded body 25 in the tray 21.

  By the way, rare earth alloy magnetic powder reacts with oxygen rapidly in the atmosphere and generates heat. Further, when the rare earth alloy magnetic powder is oxidized by contact with oxygen, desired characteristics as the magnetic powder cannot be obtained. Therefore, the entire space where the processes from weighing to molding and removal are divided, and the inside is made with a slight positive pressure by a nitrogen purge to prevent the rare earth alloy magnetic powder from coming into contact with oxygen (below) Patent Document 3).

Japanese Patent Laid-Open No. 4-158007 Japanese Utility Model Publication No. 1-84900 JP 2007-83280 A (proposed by the present applicant)

  As long as powder is handled, dust is inevitable. For example, in the molding process of FIG. 3B, some molding materials are not molded and remain as burrs 31 (magnetic powder), which causes dust in the next process. For example, the burrs 31 are removed by air blowing in the deburring step of FIG. 3E (Patent Document 2), but the dust that has risen by the air blowing drifts in the space purged with nitrogen, and finally the tray 21. And adhere to devices such as the loading robot 20. Similarly, when air blow is performed on the mold (Patent Document 1), the magnetic powder adhering to the mold rises, causing deterioration of the environment in the nitrogen purged space. Here, considering that nitrogen is more expensive than normal air, for example, dust collection (suction) or opening to the atmosphere in a slightly positive pressure nitrogen space for cleaning, a lot of nitrogen is wasted. Therefore, it is desirable to reduce the number of times as much as possible. In addition, it is desirable to reduce nitrogen release by cleaning as much as possible from the point that care must be taken not to run out of oxygen with a large amount of nitrogen release.

  The present invention has been made in view of such a situation, and an object of the present invention is to provide a metal powder molding system capable of reducing waste of nitrogen as compared with the prior art.

An aspect of the present invention is a metal powder molding system,
A booth where the inside can be in a nitrogen atmosphere,
Nitrogen supply means for supplying nitrogen into the booth;
Gas circulating means for sucking gas from inside the booth and returning it to the booth through a filter ;
A molding machine for compressing and molding magnetic material powder in a mold;
A first clamp for removing the molded body from the molding machine;
A coil for applying an alternating magnetic field to the molded body held at a predetermined position by the first clamp;
A duct that opens at one end of the coil and communicates with the suction side of the gas circulation means;
First nitrogen spraying means for spraying nitrogen onto a molded body held by the first clamp and positioned in the vicinity of the coil .

  You may provide the 1st hood which surrounds the circumference | surroundings of the molded object hold | gripped by the said 1st clamp and located in the vicinity of the said coil.

  A temporary placement portion for placing the molded body taken out by the first clamp, a second nitrogen spraying means for blowing nitrogen to the molded body placed on the temporary placement portion, and an opening in the vicinity of the temporary placement portion. A duct communicating with the suction side of the gas circulation means may be provided.

  You may provide the 2nd food | hood surrounding the circumference | surroundings of the said temporary placement part.

  A second clamp for picking up the molded body placed on the temporary placement section may be provided, and a nitrogen blowing port of the second nitrogen blowing means may be opened at a predetermined position of the second clamp.

  The second nitrogen spraying means may spray nitrogen onto a surface of the molded body placed on the temporary placement part and held by the first clamp.

  A first shutter capable of opening and closing a first air flow path passing through the coil and reaching the suction side of the gas circulation means; and a second shutter reaching the suction side of the gas circulation means through the vicinity of the temporary storage portion You may provide the 2nd shutter which can open and close an air flow path.

  When nitrogen is blown by the first nitrogen blowing means, the first shutter is opened and the second shutter is closed, while when nitrogen is blown by the second nitrogen blowing means, the first shutter is opened. Close The second shutter may be opened.

  You may provide the trap which branches and drops a part of metal powder from the circulation path of the said gas circulation means before the said filter.

  The trap includes a branch passage branched from the circulation path of the gas circulation means, first and second valves provided in series in the middle of the branch passage, and a container provided at an end of the branch passage. And the first and second valves can be separated from each other as a boundary, and the first and second valves can be purged with nitrogen.

  Rare earth alloy magnetic powder may be a molding target.

  It should be noted that any combination of the above-described constituent elements, and those obtained by converting the expression of the present invention between methods and systems are also effective as aspects of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, the shaping | molding system of metal powder which can reduce the waste of nitrogen compared with the former can be provided.

The principal part schematic block diagram of the shaping | molding system of the metal powder which concerns on embodiment of this invention. FIG. 2 is an overall schematic configuration diagram of the metal powder molding system of FIG. 1. FIG. 3 is an exemplary process explanatory diagram from molding of rare earth alloy magnetic powder to loading of a molded body on a tray.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same or equivalent component, member, etc. which are shown by each drawing, and the overlapping description is abbreviate | omitted suitably. In addition, the embodiments do not limit the invention but are exemplifications, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

  FIG. 1A is a schematic configuration diagram of a main part of a metal powder molding system according to an embodiment of the present invention. FIG. 1B is an enlarged view of the stacking clamp 52 shown in FIG. 1A and the vicinity thereof. 2A is a plan view showing an overall schematic configuration of the metal powder molding system shown in FIG. FIG. 2B is a front view of the same. In order to show the correspondence between FIG. 2 (B) and FIG. 1 (A), the reduced version of FIG. 1 (A) is shown again as FIG. 2 (C).

  As shown in FIG. 2A, the booth 1 surrounds the weighing chamber 16, the molding chamber 17, and the loading chamber 18 to ensure airtightness with the outside. The weighing chamber 16 accommodates a weighing machine (not shown) for weighing the molding material (metal powder such as rare earth alloy magnetic powder). The molding chamber 17 accommodates a molding machine (not shown) that compresses the molding material measured by the weighing machine with a mold (an apparatus that performs the molding process shown in FIG. 3B). The loading chamber 18 accommodates each device that performs from deburring described later to loading on the tray 21. The take-out robot 19 in the loading chamber 18 takes out the molded body 25 from the molding machine, and the loading robot 20 stores the molded body 25 in the tray 21. The weighing chamber 16, the molding chamber 17, and the loading chamber 18 can be spatially partitioned by gate valves. The weighing chamber 16, the molding chamber 17, and the loading chamber 18 are provided with check valves 44 to 46, respectively, and each chamber can be individually purged with nitrogen and exhausted. The blower 2 functions as a gas circulation means for sucking gas from the booth 1 and returning it to the booth 1 through the filter 3 (FIG. 1A).

As shown in FIG. 1A, a nitrogen supply pipe 56 is connected to the booth 1, and the inside of the booth 1 can be purged with nitrogen by opening a valve 57. The take-out clamp 4 corresponds to the hand of the take-out robot 19 (FIG. 2A). The deburring coil 7 (hollow coil) applies an alternating magnetic field (preferably a damped oscillating magnetic field) to the molded body 25. One end opening of the deburring coil 7 is close to or communicates with the opening of the duct 8 in the booth. A first shutter 6 (sliding type in the illustrated example) is provided at the other end opening of the deburring coil 7 so that the other end opening of the deburring coil 7 can be opened and closed. A cylindrical fixed hood 5 is provided in the vicinity of the other end of the deburring coil 7, and the nozzle 22 is provided inside the fixed hood 5 so that nitrogen can be ejected. The suction speed (surface speed) at the opening of the deburring coil 7 due to the suction of the blower 2 is about 6 m / mm at the opening surface of the fixed hood 5 with the first shutter 6 opened and the second shutter 12 closed. For example, the opening area of the fixed hood is set to 25500 mm ² . Further, the flow rate of nitrogen blow from the nozzle 22 is, for example, 470 L / min, and the flow rate is 33 m / sec.

The temporary placement table 11 as a temporary placement unit is provided for temporarily placing the molded body 25 before being loaded on the tray 21. The periphery of the temporary table 11 is made of a material capable of sucking nitrogen such as a net. The cylindrical vertically movable hood 9 is provided so as to be able to descend so as to surround the temporary table 11 and to be retracted above the temporary table 11. The loading clamp 10 corresponds to the hand of the loading robot 20 (FIG. 2A). As shown in FIG. 1B in an enlarged manner, the stacking clamp 10 is supplied with nitrogen through the tube 23 and has a blow-out port 24 through which the supplied nitrogen is ejected. An in-booth duct 8 is opened in the vicinity (downward) of the temporary table 11, and a second shutter 12 capable of blocking the airflow from the opening is provided at the opening of the in-booth duct 8 so as to be opened and closed. The second shutter 12 is not limited to the illustrated rotary type but may be a slide type. Further, the booth duct 8 is common to the deburring coil 7 side and the temporary placing table 11 side, but may be provided separately. The in-booth duct 8 communicates with the outside booth duct 15. The opening area of the vertically movable hood 9 is, for example, 35000 mm ² . Further, the flow rate of nitrogen blow by the loading clamp 10 is 50 m / sec, the flow rate is 100 L / min, the distance from the molded body 25 is about 2 mm, and the descending speed for holding the molded body 25 while performing nitrogen blowing. Is 80 mm / sec.

The outside booth duct 15 guides the gas in the booth 1 to the blower 2. A valve 53 is provided at the inlet of the blower 2 and a valve 54 is provided at the outlet. For example, the blower 2 has a processing flow rate of 10 m ³ / min at 2.2 kw. The in-pipe flow velocity of the duct 15 outside the booth due to the suction of the blower 2 is 15 to 20 m / sec. The blower 2 includes a filter 3, and passes the gas sucked from the booth 1 through the filter 3 and returns it to the booth 1. The filtration area of the filter 3 is, for example, 6.0 m ² . A pipe 32 is connected to the subsequent stage of the filter 3, and nitrogen can be supplied through the valve 47 for backwashing the filter 3. Backwashing is an operation in which airflow in the reverse direction is passed through the filter 3 to blow off clogging.

  The pot 49 is provided to receive the dust that has fallen through the valve 53 at the entrance of the blower 2. Valves 39 and 40 are provided in series between the valve 53 and the pot 49 (fall path 55). The pot 49, the valves 39 and 40, and the dropping path 55 form a trap for dust carried by the airflow. A pipe 33 is connected to the space between the valves 39 and 40, and nitrogen can be supplied through the valves 41 to 43. The space between the valves 39 and 40 is connected to the factory duct 50 via a check valve 51. The pot 49 can be removed together with the valve 40.

  The branch duct 36 branches downward from the booth outer duct 15. Valves 37 and 38 are provided in series in the middle of the branch duct 36. The pot 48 is provided at the end of the branch duct 36. The pot 48, valves 37 and 38, and the branch duct 36 provide another trap for dust carried in the air stream. Similarly to the space between the valves 39 and 40, a pipe (not shown) is connected to the space between the valves 37 and 38, and nitrogen can be supplied via the valve (not shown). The pot 48 can be removed together with the valve 38.

  Hereinafter, the operation of the present embodiment will be described.

  Prior to the series of processes, the inside of the booth 1 (the weighing chamber 16, the molding chamber 17, and the loading chamber 18) is purged by supplying nitrogen from the pipe 56, and exhausted through check valves 44 to 46 (fine differential pressure check valves). Then, the gas inside the booth 1 is replaced, and the inside of the booth 1 is changed from an atmospheric state to a slightly positive pressure nitrogen atmosphere (low oxygen state). The purging is performed while the gas is circulated by the blower 2. The following steps are also performed while gas circulation is performed by the blower 2. The flow from weighing by a weighing machine to molding in a magnetic field by a molding machine (mold) is performed in the same flow as before.

  The take-out robot 19 (FIG. 2A) grips the molded body 25 extracted from the mold by the take-out clamp 4 (FIG. 1A) and conveys it to the inside of the fixed hood 5 and the deburring coil 7. To do. The first shutter 6 is opened in accordance with the conveyance timing. The deburring coil 7 applies an alternating magnetic field to the fixed hood 5 and the molded body 25 held inside the deburring coil 7 by the extraction clamp 4. The alternating magnetic field is preferably a magnetic field whose magnitude gradually attenuates while reversing the NS direction repeatedly. Nitrogen blow from the nozzle 22 is started at substantially the same timing as the application of the alternating magnetic field, and the magnetic powder (burrs) of the take-out clamp 4 and the molded body 25 held by the take-off clamp 4 are removed (blow off by blowing nitrogen). At this time, the second shutter 12 is closed. Dust generated by nitrogen blow from the nozzle 22 is sucked into the booth duct 8 by suction of the blower 2. The airflow at this time is indicated by an arrow 13 in FIG.

  After removing the burrs, the take-out robot 19 places the molded body 25 on the temporary placement table 11 by the take-out clamp 4. The vertically movable hood 9 rises from the retracted position below the temporary table 11 and surrounds the temporary table 11. The loading robot 20 (FIG. 2A) moves the loading clamp 10 to the vicinity of the molded body 25 on the temporary placement table 11, and performs nitrogen blowing from the outlet 24 of the loading clamp 10 to the molded body 25. Nitrogen blow (nitrogen blowing) is performed on at least the surface held by the take-off clamp 4. The burr on the surface held by the take-out clamp 4 cannot be removed by nitrogen blowing from the nozzle 22 described above, but remains by removing the remaining burr by performing nitrogen blowing by the loading clamp 10 on the temporary table 11. Removal is possible. During the nitrogen blow by the stacking clamp 10, the second shutter 12 is opened and the first shutter 6 is closed. Dust generated by nitrogen blowing by the loading clamp 10 is sucked into the booth duct 8 by suction of the blower 2. The airflow at this time is indicated by an arrow 14 in FIG. After the nitrogen blow by the loading clamp 10, the loading robot 20 picks up the molded body 25 from the temporary placement table 11 by the loading clamp 10 and loads it on the tray 21 (FIG. 2A).

  The dust sucked into the duct 8 in the booth moves along with the nitrogen through the duct 15 outside the booth 15 by the suction of the blower 2, but some of the relatively heavy dust passes through the branch duct 36 by gravity. It falls into the pot 48. Further, a part of the dust having a relatively heavy weight among the dust passing through the valve 53 falls into the pot 49 through the dropping path 55 by gravity. Dust that has not fallen into the pots 48 and 49 is sucked into the filter 3 together with nitrogen by the suction of the blower 2, and is removed by the filter 3. The nitrogen that has passed through the filter 3 returns to the booth 1 through the valve 54.

  When a predetermined amount of dust accumulates in the pot 49, the valves 39 and 40 are closed, the valve 40 and the pot 49 are removed, and the dust is safely removed from the pot 49. Thereafter, the valve 40 and the pot 49 are attached as they are, and the space between the valves 39 and 40 is purged with, for example, 0.4 MPa nitrogen from the pipe 33, and then the valves 39 and 40 are opened. The same operation is performed when a predetermined amount of dust has accumulated in the pot 48. Thereby, it can prevent that dust touches oxygen or oxygen enters the booth 1.

  When the filter 3 is used for a predetermined period, backwashing is performed. The valve 47 is opened and 0.7 MPa of nitrogen is supplied from the pipe 32 to the subsequent stage of the filter 3 to blow off the clogging of the filter 3. The dust blown off falls into the pot 49. For example, nine filters included in the filter 3 are back-washed, for example, three at regular intervals.

  According to the present embodiment, the following effects can be achieved.

(1) Since the nitrogen in the booth 1 is circulated through the filter 3 by the blower 2, dust flowing in the booth 1 can be sucked and removed, and the environment in the booth 1 can be cleaned. In addition, this makes it possible to lengthen the cycle of cleaning and the like, which is advantageous for saving nitrogen.

(2) Since the in-booth duct 8 is open in the vicinity of the place where nitrogen blowing for deburring, where dust easily flies, (one end of the deburring coil 7 and the vicinity of the temporary table 11), the nitrogen blowing is performed. It is possible to suitably prevent the dust from rising by suction from the opening of the duct 8 in the booth.

(3) When nitrogen is blown from the nozzle 22, the first shutter 6 is opened and the second shutter 12 is closed, and when nitrogen is blown from the outlet 24 of the stacking clamp 10, the first shutter 6 is closed and the second shutter is closed. By opening 12, the flow velocity in the vicinity of the molded body 25 where nitrogen blowing is performed can be increased, and dust suction efficiency is high.

(4) The blower 2 is operated when the inside of the booth 1 is changed from the atmospheric state to the low oxygen state, and the gas flow in the booth 1 is promoted by the circulating flow generated thereby, and the stagnation generated only by the normal purge. Is unlikely to occur. Therefore, since a stabilization time (for example, 2 minutes) for starch is not required, 5,000 L / min × 2 minutes = 10,000 L of nitrogen can be saved per purge. The amount of use until the purge is completed is, for example, 5,000 L / min × 20 minutes (replacement time) = 100,000 L, and nitrogen corresponding to about 10% can be saved by operating the blower 2 at the time of purging.

(5) Since nitrogen blow is performed from the outlet 24 of the stacking clamp 10 to the surface of the molded body 25 on the temporary table 11 that has been gripped by the take-out clamp 4, burrs on the face that has been gripped by the take-out clamp 4 also occur. It can be removed.

(6) Since the trap for collecting relatively heavy dust in the pots 48 and 49 is provided in the upstream of the filter 3 in the middle of the circulation path by the blower 2, the speed at which the filter 3 gets dirty can be reduced.

  The present invention has been described above by taking the embodiment as an example. However, it is understood by those skilled in the art that various modifications can be made to each component and each processing process of the embodiment within the scope of the claims. By the way.

1 Booth, 2 Blower, 3 Filter, 4 Extraction clamp, 5 Fixed hood, 6 First shutter, 7 Deburring coil, 8 Booth duct, 9 Vertical movable hood, 10 Loading clamp, 11 Temporary table, 12 2nd Shutter, 13, 14 arrow, 15 duct outside booth, 16 weighing chamber, 17 molding chamber, 18 loading chamber, 19 take-out robot, 20 loading robot, 21 tray, 22 nozzle, 23 tube, 24 outlet, 25 molded body, 26 molding material, 27 die, 28 lower punch, 29 upper punch, 30 electromagnet, 31 burr, 32, 33 piping, 36 branch duct, 37-43 valve, 44-46 check valve (fine differential pressure check valve), 47 valves, 48,49 pots, 50 factory ducts, 51 check valves, 52 loading clamps, 53,54 valves, 5 fall path, 56 pipe, 57 valve

Claims (11)

A booth where the inside can be in a nitrogen atmosphere,
Nitrogen supply means for supplying nitrogen into the booth;
Gas circulating means for sucking gas from inside the booth and returning it to the booth through a filter ;
A molding machine for compressing and molding magnetic material powder in a mold;
A first clamp for removing the molded body from the molding machine;
A coil for applying an alternating magnetic field to the molded body held at a predetermined position by the first clamp;
A duct that opens at one end of the coil and communicates with the suction side of the gas circulation means;
A metal powder molding system comprising: a first nitrogen spraying means for spraying nitrogen onto a molded body held by the first clamp and positioned in the vicinity of the coil . 2. The metal powder molding system according to claim 1, further comprising a first hood that is held by the first clamp and surrounds a molded body that is positioned in the vicinity of the coil. A temporary placement portion for placing the molded body taken out by the first clamp, a second nitrogen spraying means for blowing nitrogen to the molded body placed on the temporary placement portion, and an opening in the vicinity of the temporary placement portion. wherein the suction side of the gas circulation means and a duct communicating, molding system of metal powder according to claim 1 or 2. The metal powder molding system according to claim 3 , further comprising a second hood surrounding the temporary storage portion. A second clamp to take up molded body placed on the temporary placement portion, the nitrogen blowing port of the second nitrogen spraying means is opened to a predetermined position of the second clamp, according to claim 3 or 4. The metal powder molding system according to 4. The second nitrogen spraying means, said placed temporary unit molded body, blowing nitrogen on the first surface that has been gripped by the clamp, according to any one of claims 3 to 5 Metal powder molding system. A first shutter capable of opening and closing a first air flow path passing through the coil and reaching the suction side of the gas circulation means; and a second shutter reaching the suction side of the gas circulation means through the vicinity of the temporary storage portion The metal powder molding system according to any one of claims 3 to 6 , further comprising a second shutter capable of opening and closing the air flow path. When nitrogen is blown by the first nitrogen blowing means, the first shutter is opened and the second shutter is closed, while when nitrogen is blown by the second nitrogen blowing means, the first shutter is opened. The metal powder molding system according to claim 7 , wherein the second shutter is closed and the second shutter is opened. The metal powder molding system according to any one of claims 1 to 8 , further comprising a trap for dropping a part of the metal powder from the circulation path of the gas circulation means before the filter. The trap includes a branch passage branched from the circulation path of the gas circulation means, first and second valves provided in series in the middle of the branch passage, and a container provided at an end of the branch passage. 10. The metal powder according to claim 9 , wherein the metal powder is separable at a boundary between the first and second valves and can be purged with nitrogen between the first and second valves. Body molding system. The metal powder molding system according to any one of claims 1 to 10 , wherein the rare earth alloy magnetic powder is a molding object.