JPH07178598A - In-magnetic field wet type molding device - Google Patents

Abstract

PURPOSE:To provide an in-magnetic field wet type molding device capable of forming moldings of extremely small permanent magnets with high efficiency by providing this device with plural pieces of die sets and continuously executing operations for raw material supplying, molding, taking out of moldings and cleaning of metal molds. CONSTITUTION:This molding device is provided with plural pieces of the die sets 32 having dies and lower punches on an index table 24 rotating at every prescribed central angle within a horizontal plane and is provided with a raw material supplying unit which supplies the fixed amt. each of a slurry formed by dispersing oxide magnetic powder into a solvent, a molding unit 50, a molding taking out unit and a metal mold cleaning unit in the positions facing the die sets 32 in such a manner that these operations are continuously executed for higher efficiency. The die sets 32 are provided with liquid magnetic field coils 58 together with liquid discharging means and filter cloth units. An advantage is thus taken of the magnetic characteristics by the wet type molding means. As a result, the permanent magnet having improved orientability and high timing characteristics is formed with high efficiency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a slurry obtained by dispersing oxide magnetic powder in water or other solvent as a raw material to form a molded body of an oxide permanent magnet with a molding die to which a magnetic field is applied. It relates to a wet molding machine in a magnetic field,
In particular, the present invention relates to a magnetic field wet molding apparatus capable of high-efficiency molding.

[0002]

2. Description of the Related Art Conventionally, powder metallurgical means has been widely used as a means for producing oxide permanent magnets such as ferrite magnets, and in order to improve magnetic characteristics, molding is performed by a molding die to which a magnetic field is applied. A so-called magnetic field forming means for obtaining a body is known. In this case, there are two types: dry molding means that uses the raw material oxide magnetic powder in a dry state, and wet molding means that uses a slurry obtained by dispersing the oxide magnetic powder in water or another solvent as the raw material. is there.

Although the dry molding means has a high molding efficiency, it has a problem that the magnetic characteristics are inevitably deteriorated because the orientation degree of the magnetic powder in the magnetic field is relatively low. For this reason, in order to improve the magnetic properties, it is considered advantageous to use a wet-molding means in which the orientation of the magnetic powder in a magnetic field is easy, for example, Japanese Patent Publication No. 55-6401.
No. 55-10364, No. 59-8047, etc. have been proposed.

FIG. 8 is an explanatory longitudinal sectional view of an essential part showing an example of a wet molding apparatus in a magnetic field. In FIG. 8, 1 is a die,
It has a through hole 2 and is connected to the lower hydraulic cylinder 3 so as to be movable up and down. Reference numeral 4 is a lower punch, which is fixed on a base 5 and through a packing 6 through hole 2 of the die 1.
Has been inserted inside. Next, 7 is an upper punch, and a filter cloth 8
It is formed so as to be in contact with the upper surface of the die 1 through and is connected to the upper hydraulic cylinder 9 so as to be vertically movable. A drainage hole 10 is provided in the lower end surface of the upper punch 7 and communicates with a drainage chamber 11 provided in the upper punch 7.
A drainage pipe 12 is connected to 1. With the above structure, the molding cavity 13 is formed in the die 1.

Next, 14 is a magnetic field coil for applying a magnetic field to the molding cavity 13. 15 is a slurry supply pipe, and two valves 16 and 17 are provided in the middle.
And the slurry 20 from the slurry storage tank 18 is connected to the molding cavity 13 so that it can be supplied.
Reference numeral 19 denotes a slurry pressure feeding device, which is connected to the slurry supply pipe 15 between the valves 16 and 17.

With the above structure, first, the valve 17 is closed, the valve 16 is opened, and the slurry 20 in the slurry storage tank 18 is introduced into the slurry pressure-feeding device 19.
Is closed, the valve 17 is opened, a predetermined amount of the slurry 20 is injected into the molding cavity 13 by the operation of the slurry pumping device 19, and the valve 17 is closed. Next, the upper punch 7 and the die 1 are lowered by the upper hydraulic cylinder 9, and the slurry (not shown) in the molding cavity 13 is compacted while applying a magnetic field via the magnetic field coil 14. During this period, the solvent in the slurry is filtered by the filter cloth 8 and the drain hole 1.
Is discharged into the drainage chamber 11 through 0, and then the drainage pipe 12
Is discharged from the outside.

In the latter stage of the compaction molding, the pressure is advanced between the upper punch 7 and the lower punch 4 while gradually lowering the pressure of the lower hydraulic cylinder 3 to support the own weight of the die 1 and the like. After the molding is completed, the upper punch 7 is raised by the upper hydraulic cylinder 9 and the die 1 is lowered by the lower hydraulic cylinder 3 to take out the compact in the molding cavity 13.

[0008]

According to the wet molding apparatus in a magnetic field as described above, the degree of orientation of the molded body is improved and a permanent magnet having high magnetic properties can be obtained. There are problems that the molding cycle time is long and the molding efficiency is low. That is, the molding time of the molded body is long because the solvent in the slurry is discharged during molding.

When the molding time is shortened, the density of the magnetic powder in the compact becomes different between the upper punch 7 side having the drainage hole 10 and the lower punch 4 side not having the drain hole 10, so that the permanent magnet after firing has a different density. There are problems such as deformation and nonuniform magnetic properties.

Further, when the dimension of the compact in the direction of compaction becomes smaller, the molding time can be shortened, but the slurry injection time before and after the molding step, the removal of the compact,
The molding cycle time including the time required for cleaning the molding cavity is longer than that of the dry molding means, and the problem of low molding efficiency remains unsolved.

The present invention solves the above-mentioned problems existing in the prior art, for example, a wet process in a magnetic field capable of continuously forming a compact body of a permanent magnet having a thickness of 10 mm or less and a weight of 10 g or less with high efficiency. An object is to provide a molding device.

[0012]

In order to achieve the above object, in the present invention, the vertical direction is provided on an index table which has a vertical rotation axis and is selectively rotatable in a horizontal plane toward a predetermined central angle. A plurality of die sets, each of which has a die movable relative to each other and a lower punch, and which constitutes a forming cavity, are provided at equal intervals in the circumferential direction at the same radial position, and oxide magnetism is provided at a position facing the die set. A raw material supply unit for supplying a fixed amount of a slurry in which powder is dispersed in a solvent, a molding unit, and a molded body unloading unit are respectively provided along the rotation direction of the index table, and the molding unit is connected to the die set. An upper punch and an upper punch which are provided above and configured to be movable up and down, and which has a drainage hole at a lower end surface and is provided with a drainage means communicating with the drainage hole. By a filter cloth unit in which a filter cloth interposed between the iset is formed so as to be movable in the horizontal direction, and a magnetic field coil which is provided below the die set and which forms a magnetic field in a direction traversing the upper punch and the lower punch, Constitute,
I adopted the technical means.

[0013]

With the above construction, the index table is selectively rotated and stopped at a predetermined center angle, for example, 90 °, so that the raw material slurry is quantitatively supplied to the molding cavity in the raw material supply unit to form the molding unit. In the above, pressure molding is performed in a magnetic field to obtain a molded product having a predetermined shape and size. Next, the molded body is taken out from the molding cavity in the molded body take-out unit, the molding cavity is cleaned and the release agent is applied in the mold cleaning unit for the next molding, and the next molding cycle is sequentially repeated. Of. In this way, the conventional molding cycle is divided, and the respective divided steps proceed sequentially and simultaneously, so that the cycle time can be greatly shortened, and highly efficient and continuous molding becomes possible.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 to 3 are front views of essential parts, plan views of essential parts and right side views of partial essential parts showing an embodiment of the present invention, respectively.
FIG. 4 is a cross-sectional plan view of a main part taken along the line AA in FIG. 1 to 4, reference numeral 21 is a box-shaped lower frame, and 22 is an upper frame provided on the lower frame 21 via columns 23, which are integrally formed of a steel material.

Reference numeral 24 denotes an index table, which is formed integrally with a vertical rotation shaft 25 provided between the lower frame 21 and the upper frame 22, and has an upper surface of the lower frame 21 at a predetermined central angle within a horizontal plane, for example, 90. It is formed so that it can be selectively rotated. A drive motor 26 is provided on the upper frame 22, and is configured to be able to drive the vertical rotation shaft 25 via a reduction gear 27 and gears 28 and 29. Reference numeral 30 denotes a positioning unit, which is provided on the lower frame 21 and is formed so as to be engageable with and disengageable from a positioning hole 31 provided on the outer circumference of the index table 24.

Next, 32 is a die set, which is formed as will be described later, and is provided on the index table 24 at equal intervals in the circumferential direction and at the same radial position from the axis of the vertical rotation shaft 25. Reference numerals 40, 50, 60 and 70 denote a raw material supply unit, a molding unit, a molded body take-out unit and a mold cleaning unit, respectively, and the index table 24, respectively.
At the position facing the die set 32 provided above, the index table 24 is provided in the rotation direction (counterclockwise direction in FIG. 4) in the above order.

The raw material supply unit 40 is formed so that the oxide magnetic powder is dispersed in a solvent such as water so that a slurry having a concentration of, for example, 70 to 80% by weight can be supplied to a molding cavity described later in a fixed amount. To do. For example, by using a commercially available dispenser and controlling the pressure and pressure feeding time from a nozzle 41 connected to a slurry accommodating tank (not shown, reference numeral 18 in FIG. 8) that can be pressurized through a pipe, Can be supplied to a fixed amount.

Next, the structure of the molding unit 50 will be described. Reference numeral 51 is a driving motor, which is the upper frame 22.
An output shaft 52 having a ball screw provided above is projected downward. 53 is an upper punch holder, and the output shaft 5
It is formed so as to be screwed with the shaft 2 and movable up and down by the rotation of the output shaft 52, and the upper punch 54 is detachably provided at the lower end portion. The upper punch 54 is provided with a drainage means having the same configuration as the upper punch 7 shown in FIG. Reference numeral 33 denotes a guide bar, which is a bracket 3 provided on the upper punch holder 53.
The guides 35 are provided on both ends of the guide frame 4 and are engaged with the guides 35 provided on the upper frame 22 so as to be vertically movable. An equalizer 36 is connected to the upper end of the guide bar 33. Three
7 is a filter cloth unit, and the upper punch 54 and the die set 3
The filter cloth 38 is intermittently moved horizontally between the two.

Reference numeral 55 designates a pressure receiving cylinder formed in a hollow cylindrical shape, and 56.
Is a hydraulic cylinder, and 57 is a pressure receiving rod that is vertically driven by the hydraulic cylinder 56.
Is provided coaxially with the pressure receiving cylinder 55, and the upper end surfaces of the pressure receiving cylinder 55 and the pressure receiving rod 57 can be engaged with and disengaged from the die set 32. Reference numeral 58 is a magnetic field coil, which is provided on the lower frame 21 coaxially with the pressure receiving cylinder 55 and the pressure receiving rod 57, and is for forming a magnetic field in a direction traversing the upper punch 54, the die set 32 and the pressure receiving rod 57. Is. Reference numeral 59 denotes a yoke, which is made of, for example, a ferromagnetic steel material and is formed into a substantially L shape, and is provided so as to magnetically connect the vertical rotation shaft 25 and the pressure receiving rod 57.

Next, the structure of the molded product take-out unit 60 will be described. 61 is a take-out cylinder, and the bracket 6
It is attached to the main body 63 via 2. The suction means 6 is attached to the tip of the rod 64 formed so as to be movable in the direction of the arrow.
5 is attached so as to be vertically movable. 66 is a suction pad, which is a cavity for molding the die set 32 (not shown)
Is provided at a position corresponding to, and is connected to a vacuum source (not shown) via an intake pipe 67. Reference numeral 68 denotes a conveyor, which conveys the molded body taken out to the next step.

The die cleaning unit 70 includes a die set 3
A nozzle 71 facing the second molding cavity (not shown) is provided and connected to a compressed air source and a release agent supply source (neither shown).

With the above structure, first, the slurry is quantitatively supplied from the nozzle 41 constituting the raw material supply unit 40 into the molding cavities (four in this embodiment) in the die set 32, and then the positioning unit 30 is moved. The index table 24 is removed from the positioning hole 31, the index table 24 is rotated 90 ° counterclockwise in FIG. 4 and stopped, and the positioning unit 30 is engaged with the positioning hole 31.

Next, in the molding unit 50, the driving motor 51 is operated to lower the upper punch 54 via the output shaft 52 and the upper punch holder 53 to perform molding. In this case, since the lower end portion of the die set 32 is supported by the pressure receiving cylinder 55 and the pressure receiving rod 57, the slurry in the molding cavity is compacted to form a compact having a predetermined shape and size. The solvent in the slurry is discharged through the drainage means provided in the upper punch 54.

In the molded-body take-out unit 60, the suction cylinder 61 is actuated to move the suction means 65 to the left in FIGS. 1 and 2 so as to directly face the molded body of the die set 32. Next, the suction means 65 descends and comes into contact with the upper surface of the molded body, and a vacuum is applied to the suction pad 66 to suck the molded body and move it upward and to the right in FIGS. 1 and 2. The molded body is placed on the conveyor 68.

The die set 32 from which the molded body is taken out reaches the mold cleaning unit 70 by the 90 ° rotation of the index table 24, and the molding cavity is cleaned by blowing the compressed air from the nozzle 71, and the mold releasing agent is removed. The next preparation for molding is completed by spraying. Thereafter, the die set 32 is moved to the raw material supply unit 40 by rotating the index table 24 by 90 °, and the above cycle is repeated.

FIG. 5 is an explanatory view showing an example of a die set in the embodiment of the present invention, (a) is a longitudinal sectional view of a main part, and (b) is a sectional view.
Indicates the plane of the main part, and the same parts are denoted by the same reference numerals as those in FIGS. 1, 3 and 4. Note that FIG. 5 shows a state at the position of the raw material supply unit 40 in FIG.
In FIG. 5, reference numeral 81 denotes a base plate, which is made of, for example, a ferromagnetic steel material in a plate shape, and has a mounting bolt 82.
It is mounted on the index table 24 via. Reference numeral 83 denotes a support plate, which is fixed below the base plate 81 via a spacer 84. Base plate 81
A lower punch 85 made of, for example, a ferromagnetic steel material is fixed to the central portion of the.

Next, 86 is a die holder, for example, S
A plate 88 is formed of a non-magnetic steel material such as US304, and is formed of a non-magnetic wear-resistant metal material such as SUS304 in the central portion. For example, a die 88 having four through holes 87 is attached. It is fixed via the ring 89. Reference numeral 90 denotes a support member, which is connected to the die holder 86 via the guide rod 91. The guide rod 91 is a linear ball bearing 92 provided on the base plate 81.
It is formed to be movable up and down through. The lower punch 85 is inserted into a through hole 87 formed in the die 88 to form a molding cavity 93.

Next, reference numerals 94 and 95 are rails, which are provided on the lower frame 21, and which are provided on the lower frame 21 with a sliding portion 96 protruding below the supporting plate 83 and a sliding portion protruding below the supporting member 90. It is formed in a ring shape in a plane so as to slidably support 97. In this case,
If the outer diameters of the sliding portions 96 and 97 are D and d, the rail 94
Is 2 with a width of at least (D−d) / 2 through the distance d.
The rail 95 is formed to have a width less than d and is provided in the middle of the rail 94.

With the above structure, the raw material supply unit 40
In the above, in the state shown in FIG. 5, the slurry is quantitatively supplied from the nozzle 41 into the molding cavity 93 as described above. After the slurry is supplied, the index table 24 moves to the next forming unit (not shown, see reference numeral 50 in FIG. 4), but the die 88 and the lower punch 85 have the sliding portions 96, 97 with the rails 94, 9 respectively.
5 slides, the state of the molding cavity 93 shown in FIG. 5A can be maintained.

FIG. 6 is a longitudinal sectional view of an essential part showing the state of the die set at the position of the molding unit in the embodiment of the present invention, and the same parts are designated by the same reference numerals as those in FIGS. 3, 4 and 5. . In FIG. 6, the filter cloth 38 is a reel 37.
It is rewound from a and intermittently moves to the right, and reel 37
It is configured to be wound around b. Next, reference numeral 98 is a notch portion, which is provided at the upper end portion of the pressure receiving cylinder 55 and has a sliding portion 97.
Are formed to have a width dimension that allows passage.

In the die set 32 moved to the molding unit 50 in the state shown in FIG. 5A, the lower end surface of the sliding portion 96 protruding from the support plate 83 is supported by the upper end surface of the pressure receiving cylinder 55 from the rail 94. On the other hand, the lower end surface of the sliding portion 97 protruding from the one support member 90 is supported by the upper end surface of the pressure receiving rod 57 which is elevated from the rail 95 to the same plane as the rail 95. In this case, the supporting force of the pressure receiving rod 57 is the same as that of the die 88, the die holder 86, and the guide rod 9.
A value corresponding to the total weight of 1 and the supporting member 90 is maintained.

Next, when the drive motor 51 shown in FIG. 3 is operated to lower the upper punch 54, the lower end surface of the upper punch 54 contacts the upper end surface of the die 88 via the filter cloth 38 as shown in FIG. The die 88 is brought into contact and lowered to form the molding cavity 9
The slurry in 3 is compacted to form a compact 99. On the other hand, the lowering of the die 88 causes the sliding portion 97 of the supporting member 90 to lower the pressure receiving rod 57 to the position shown in FIG. Since the pressure receiving cylinder 55 is fixed at a fixed position, it supports the load associated with molding and holds the lower punch 85 at a fixed position.

When the upper punch 54 is raised and the index table 24 is rotated (moved to the right in FIG. 6) after the completion of forming, the sliding portion 96 causes the right rail 94 to move.
On the other hand, the sliding portion 97 moves to the rail 95a provided below the rail 94a. In this case, since the notch 98 is provided at the upper end of the pressure receiving cylinder 55, the pressure receiving rod 57 can be smoothly moved to the rail 95a.

FIG. 7 is a longitudinal sectional view of an essential part showing the state of the die set at the position of the molded product take-out unit in the embodiment of the present invention, and the same parts are the same as those in FIGS. 1, 2 and 4 to 6 above. Are indicated by reference numerals. In FIG. 7, when the die set 32 on the index table 24 is moved to the position of the molded body take-out unit 60, the rail 95a is positioned below the inclined portion 95c, so that the support member 90 is attached to the support plate 83. It descends to the contact position. Therefore, the die 88 also descends, and the compact 99 is exposed on the lower punch 85. In this case, since the guide rod 91 is formed so as to be vertically movable with the base plate 81 via the linear ball bearing 92, the lowering operation of the die 88 is extremely smoothly performed.

Next, the suction means 65 is lowered onto the molded body 99, and the molded body 99 is taken out by the suction pad 66 and placed on the conveyor 68 shown in FIGS. 1 and 2.
After the molded body 99 is taken out, the die set 32 is moved to the right of the index table 24, so that the sliding portion projecting below the support member 90 has the slanted portion 95d interposed between the rail 9 and the slide portion.
Return to 5. Therefore, the guide rod 91, the die holder 86, and the die 88 move up to the state shown in FIG. 5, and the molding cavity 93 is formed in the die 88.

In the mold cleaning unit 70 shown in FIG. 4, since the die set 32 is held in the state shown in FIG. 5, the inside of the molding cavity 93 is cleaned and the release agent is sprayed as described above. Then, the next molding preparation is completed. After that, the above operation is repeated.

In this embodiment, the example in which the number of molding cavities 93 provided in the die 88 is four has been described, but the number may be any number in consideration of the shape size of the molded body 99 and the like. Also, the number of die sets 32 provided on the index table 24 can be set to an appropriate number depending on the mode of each unit and the like, and the indexing angle or the rotation angle of the index table 24 can be correspondingly set. Just set it. Further, a part of the upper punch 54 may be formed so as to enter the molding cavity 93 in the die 88 in accordance with the shape and size of the molded body 99.

[0038]

EFFECTS OF THE INVENTION Since the present invention has the constitution and operation as described above, it is possible to continuously perform wet molding work in a magnetic field with high efficiency, which conventionally required a long molding cycle time. There is an effect that productivity can be improved and manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a front view of essential parts showing an embodiment of the present invention.

FIG. 2 is a plan view of an essential part showing an embodiment of the present invention.

FIG. 3 is a right side view of an essential part of a partial cross section showing an embodiment of the present invention.

FIG. 4 is a cross-sectional plan view of the main part taken along the line AA in FIG.

5A and 5B are explanatory views showing an example of a die set according to an embodiment of the present invention, in which FIG. 5A is a longitudinal sectional view of a main part, and FIG.

FIG. 6 is a longitudinal sectional view of an essential part showing the state of the die set at the position of the molding unit in the example of the present invention.

FIG. 7 is a longitudinal sectional view of a main part showing a state of a die set at a position of a molded body take-out unit according to the embodiment of the present invention.

FIG. 8 is a longitudinal cross-sectional explanatory view of a main part showing an example of a wet molding apparatus in a magnetic field.

[Explanation of symbols]

 24 Index Table 32 Die Set 40 Raw Material Supply Unit 50 Molding Unit 60 Molded Body Extracting Unit 70 Mold Cleaning Unit 54 Upper Punch 85 Lower Punch 88 Die 58 Magnetic Field Coil

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location H01F 41/02 G

Claims (1)

[Claims] 1. A molding cavity having a die and a lower punch which are vertically movable relative to each other on an index table which has a vertical rotation axis and is selectively rotatable in a horizontal plane toward a predetermined center angle. A plurality of die sets constituting the above are installed at equal intervals in the circumferential direction at the same radial position,
A raw material supply unit, a molding unit, and a molded body unloading unit for supplying a fixed amount of a slurry in which an oxide magnetic powder is dispersed in a solvent are provided at positions facing the die set along the rotation direction of the index table. Together with the upper punch and the upper punch, the molding unit is provided above the die set so as to be movable up and down, and has a drainage hole at a lower end surface thereof and a drainage means communicating with the drainage hole. A filter cloth unit in which a filter cloth interposed between the die set and the die set is formed so as to be movable in the horizontal direction; a magnetic field coil which is provided below the die set and which forms a magnetic field in a direction traversing the upper punch and the lower punch; A wet molding apparatus in a magnetic field characterized by being constituted by: