JP2002105505A - Method and apparatus for molding powder and granular material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform press-molding by sufficiently releasing air coexistent with powder and granular material filled in a molding die. SOLUTION: This method for molding the powder and granular material comprises a flask assembling step for assembling a flask 12 by a plurality of separable split frame members 16, 16, 17 and 17 for the flask, a filling step for filling the powder and granular material into a powder and granular material filling space S inside the flask 12, and a molding step for molding the filled powder and granular material by pressing the filled powder and granular material with the upper and lower dies 13 and 14. The molding step comprises a pre-pressing step for performing the molding in the state of forming an air releasing space formed between the adjacent split frame members 16 and 17 for the flask, and a post-pressing step for performing the molding in the state of closing or reducing the air releasing after the pre-pressing step, and the pressure for pressing the powder and granular material in the post-pressing step is higher than that of the pre-pressing step.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding method and a molding apparatus for obtaining a molded body by press-molding a molding raw material made of a granular material such as metal or ceramics filled in a space filled with a granular material. It is about. The term "granules" refers to very fine powders, granules having only larger diameters than the powders, or mixtures of these powders and granules. The molded product obtained by the pressure molding becomes a sintered alloy product, a porcelain product, etc. through a firing step or the like.

[0002]

2. Description of the Related Art Conventionally, as a molding apparatus for forming a granular material under pressure, there is one described in JP-A-11-90913. As shown in FIGS. 6 and 7, the molding apparatus 1 includes four separable frame-type divided frame members 6 for assembling the frame 2 that forms the powder-filled space S inside.
6, 7, 7 and upper and lower dies 3, 4 which can be arranged so as to cover the granular material filling space S from above and below, and predetermined frame-type divided frame members 6, 6 toward the granular material filling space S. And press means for pressing the upper and lower dies 3 and 4 toward the inside of the granular material filling space S.

A molding method using the molding apparatus 1 includes a frame mold assembly process of assembling the frame mold 2 with the frame mold divided frame members 6, 6, 7, and 7, and a method of filling the inside of the frame mold 2 with the powdery and granular materials. A filling step of filling the space S with the granular material, a molding step of pressing the filled body P made of the filled granular material with the upper and lower molds 3 and 4, and separating the upper and lower molds 3 and 4 In addition, a demolding step of separating the divided frame members 6, 6, 7, and 7 of the frame mold 2 to obtain the molded body G. In the frame mold assembling process, the adjacent divided frame members 6, 7 are joined in an airtight state by pressing the frame-shaped divided frame members 6, 6 with the frame-type pressing means 8, 8.

[0004]

In the molding step, air coexisting with the granular material in the granular material filling space S is compressed by the upper and lower dies 3 and 4 and the frame. Although the air is allowed to escape from between the mold 2 and the outside, air cannot be sufficiently released and air may remain in the obtained molded body G. In particular, when the size of the molded body G in the vertical direction (Z-axis direction) is large, the residual air near the center of the molded body G is remarkable. However, the air remaining in the molded body G may expand at the time of demolding and damage the molded body, or may expand at the time of sintering in a subsequent step and cause cracks in the fired product.

The pressing force applied to the filling body P during molding is only the pressing force in the Z-axis direction applied from the upper and lower dies 3 and 4 and the reaction force in the X and Y-axis directions applied from the frame mold 2. . The pressing stress in the triaxial (X, Y, Z) directions generated in the filling body P is
In the state of powder having good fluidity, they are equal or almost equal. By the way, in the filling body P, the whole is tightly tightened with the progress of pressurization to exhibit elastic characteristics, and the stress applied from the frame mold 2 becomes smaller than the stress applied from the upper and lower molds 3 and 4, and the triaxial ( In some cases, the pressing stress in the (X, Y, Z) directions becomes non-uniform. However, a molded article obtained in a state in which the triaxial stresses are non-uniform may cause cracks in a fired product during firing in a subsequent step.

Therefore, in order to solve the above-mentioned problems, the present invention provides a method and an apparatus for molding powder and granules capable of sufficiently releasing air contained in a filler, and, if necessary, a three-axis molding method. It is an object of the present invention to provide an apparatus for molding a granular material capable of approximating a pressing stress in a direction as much as possible.

[0007]

In order to sufficiently release the air contained in the filling body, the present invention has been described.
Means adopted by the present invention described above are a frame mold assembling step of assembling a frame with a plurality of separable frame mold divided frame members, and filling the granular material filling space inside the frame mold with the granular material filling space. And a molding step of molding the filled granular material by pressing the filled granular material with upper and lower molds, wherein the molding step includes the step of forming the adjacent divided frame member for the frame mold. A pre-pressurizing step in which a gap for air release is formed therebetween; and a post-pressing step in which the gap is closed or reduced after the pre-pressing step. This is a method for molding a granular material, wherein the pressure to be pressed is higher in the post-pressing step than in the pre-pressing step.

[0008] In the present invention, in the pre-pressurizing step,
Along with compressing the air contained together with the filled powder and granular material by pressing the upper and lower molds, sufficient air is released from the air release gap formed between the adjacent frame mold divided frame members to the outside of the mold. In the post-pressurizing step, the gap between the adjacent frame-type divided frame members is closed or reduced, and the pressure is applied at a higher pressure than in the previous pressurizing step, so that the adjacent frame-type divided frame members can be discharged. Pressure molding can be carried out without allowing the powder under pressure to escape from between.

In order to ensure that the air contained in the packing material can be released quickly and reliably, the means adopted by the present invention according to the present invention is characterized in that the pre-pressurizing step comprises the steps of: 2. The method of molding a granular material according to claim 1, wherein the method is performed in a state where a second air release gap is formed between the upper and lower molds and the frame mold that have entered.

In the present invention, in the pre-pressurizing step,
The air contained together with the filled powder can be discharged to the outside from the second air release gap formed between the upper and lower molds and the frame mold, so that the air can be reliably and quickly released. be able to.

The book according to claim 3, wherein the air contained in the filler can be sufficiently released, and if necessary, the stress in the triaxial direction can be approximated as much as possible. Means adopted by the present invention are a plurality of separable frame-type divided frame members for assembling a frame forming a powder-particle filling space inside, and disposed so as to cover the powder-particle filling space from above and below. Upper and lower molds, a frame mold pressing means for pressing the frame mold divided frame member toward the granular material filling space, and one or both of the upper and lower molds toward the granular material filling space. In the apparatus for molding a granular material provided with pressing means for pressing the upper and lower molds, the pressing means for the frame mold is configured such that when the upper and lower molds are pressed by the pressing means for the upper and lower molds, the divided frame for the frame mold is pressed. The member is formed with an air release gap between adjacent frame type divided frame members. A molding apparatus before is characterized in that so as to advance toward the powder or granular material filling space from the pressing position to the pressing position after or smaller closed the gap granule. In order to be applicable to various molding conditions, the frame-type pressing means can continuously or intermittently advance the frame-type divided frame member from the pre-pressing position to the post-pressing position. Sometimes we do.

In the present invention, the granular material is filled into the space for filling the granular material inside the frame mold assembled by the plurality of divided frame members for the frame mold, and the filled granular material is placed on the upper and lower sides. It can be molded by pressing with a mold. In the first half of this pressure molding, the frame-type split frame member is stopped at the pre-pressing position to form an air escape gap between adjacent frame-type split frame members, so that the filled powder and granules can be formed. The contained air can be sufficiently discharged to the outside from the gap by pressurizing. Also, in the latter half of the pressure molding, the gap between the adjacent frame-type divided frame members is closed or reduced by advancing and stopping the frame-type divided frame member to the post-pressing position, Even if pressure is applied at a higher pressure than in the first half, the pressure molding can be performed without causing the powder under pressure to flow out from between adjacent frame-type divided frame members.
Further, in the latter half of the pressure molding, a divided frame member for a frame type is advanced around the filling material being pressure-molded in the granular material filling space toward the post-pressing position toward the granular material filling space. Since the pressing can be performed, the pressing stress in the triaxial direction generated in the filling body during the pressing can be approximated as much as possible.

In order to make it easy to change the stop position of the divided frame member for frame type, the means adopted by the present invention according to claim 4 is characterized in that the pressing means for frame type moves forward and backward to the fixed cylinder body. An output shaft and an operating shaft extending from both ends of a freely fitted piston are protruded from the cylinder main body, and the output shaft presses the frame-type split frame member; and the cylinder main body. A stop which is screwed to the operation shaft outside of the shaft and adjusts a stop position of the output shaft by abutting on the cylinder body, and the frame pressed by the output shaft by rotating the stop. 4. The powder and granular material molding apparatus according to claim 3, wherein the mold dividing frame member can be advanced from the pre-pressing position to the post-pressing position. In addition, in order to facilitate the rotation operation of the stopper, a driven gear may be provided on the outer periphery of the stopper, and the driving gear meshing with the driven gear may be rotationally driven by a servomotor. is there.

In the present invention, by adjusting the rotation of the stopper, the predetermined frame member can be advanced from the pre-pressing position to the post-pressing position. Further, by adjusting the pressure of the oil supplied to the hydraulic cylinder, it is possible to adjust the pressure applied to the predetermined frame-type divided frame member.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method and an apparatus for molding a granular material according to the present invention will be described with reference to the embodiments shown in the drawings.

FIGS. 1 to 4 show an embodiment of a molding method and a molding apparatus according to the present invention. FIG. 1 is a plan view partially showing the molding apparatus, and FIG. FIG. 3 is a partially sectional front view showing a holding device temporarily holding an integrated mold, and FIG. 4 is an assembled frame. (A) is a plan view, (B) is a front sectional view,
FIG. 5 shows the mold in a separated state.
(A) is a plan view and (B) is a front sectional view. In the following description, “right” means “right” in FIGS.
5A and the right side of FIG. 5A, and "left" refers to the left side of these figures. Further, “before” refers to the lower side of FIGS. 1, 4A and 5A, and “rear” refers to the upper side of these figures. Further, “upper” refers to FIG. 2, FIG. 4 (B) and FIG.
(B) indicates the upper side, and “lower” indicates the lower side of these figures.

The molding apparatus 10 according to the present embodiment includes a molding die 11 to be assembled, a holding device 22 for temporarily holding the molding die 11 for filling the granular material, and a filling device for the granular material. A conveying device 23 for conveying the formed molding die 11 from the holding device 22 to the molding position of the pressing device 21, and a pressing device 21 for pressing the molding die 11 filled with the granular material for pressure molding. And

As shown in FIGS. 3 to 5, the molding die 11 includes a frame die 12 having a vertically extending powder-filled space S formed therein, and an upper and lower covering the powder-filled space S. Type 1
3 and a lower mold 14, and can be assembled in a state of being placed on a bed 15. The frame mold 12 is assembled from four separable frame members 16, 16, 17, 17 and is disassembled. Four divided frame members 16, 16, 17, 17 and upper and lower dies 13, 1
4 and the bed 15 are formed from a metal material such as steel. The base 15 is provided with a through hole 15a at the center thereof.
The output shaft 43 (see FIG. 2) of the lower die pressing tool 26 that presses the lower die 14 can be made to penetrate.
The lower mold 14 has a step at the lower portion, and the step is fitted into the through hole 15 with a clearance fit so that positioning can be performed. The reason why the gap is shrunk is to enable the lower mold 14 to move to a predetermined pressing position when the molding die 11 is pressed by the pressing device 21 described later.

As shown in FIGS. 4 and 5, the divided frame members 16, 16, 17 and 17 constituting the frame 12 of the molding die 11 are in contact with each other when the adjacent divided frame members 16 and 17 come into contact with each other. Molding position for forming granule filling space S (see FIG. 4)
And a demolding position (see FIG. 5) which separates and retreats from the granular material filling space S. In each divided frame member 16, frame member shifters 18, 18 required for frame die assembly are integrally formed near both front and rear ends. The frame member shifters 18 and 18 before and after the one divided frame member 16 and the frame member shifters 18 and 18 before and after the other divided frame member 16 are separated in the left-right direction (X-axis direction) in an opposed state. , And four sets of shifting mechanisms 19, 19,... Are formed with the divided frame members 17, 17.

Each of the shifting mechanisms 19 includes a forward guiding mechanism 19a and a stopping mechanism 19b, as shown in FIG. The forward guide mechanism 19a is connected to the divided frame member 17
And the vertical direction (Z
(In the axial direction), the inclined surfaces 17a, 18a are inclined so as to be along a direction crossing the left-right direction (X-axis direction), and the dividing frame member 17 is removed from the mold removing position (see FIG. 5). ) To the molding position (see FIG. 4) so that the inclined surfaces 17a and 18a can be brought into sliding contact with each other. Slope 17a, 1
For example, 45 degrees is employed as the inclination angle θ of the 8a with respect to the X axis. The stop mechanism 19b includes stop surfaces 17b, 18b provided on the divided frame member 17 and the frame member shifter 18 and extending in the up-down direction (Z-axis direction) and the left-right direction (X-axis direction).
The stop surfaces 17b and 18b are brought into contact with each other to stop the divided frame member 17 (see FIG. 4).

As shown in FIGS. 1 and 2, the pressing device 21 for pressing the molding die 11 for pressure molding pushes the divided frame members 16 and 16 toward the space S for filling the granular material. Frame-type pressing means 25, 25 for pressing, and upper and lower dies 13, 1
And pressing means 4 for pressing the mold 4 toward the inside of the granular material filling space S (see FIG. 2). When the upper and lower dies 13 and 14 are pressed by the upper and lower die pressing means 26 and 26, the frame die pressing means 25 and 25 move the frame die divided frame members 16 and 16 to adjacent frame die divided frame members. From the pre-pressing position where a first air release gap (that is, a gap formed so as to vertically penetrate between the stop surfaces 17b and 18b shown in FIG. After the gap is closed or reduced, the gap is continuously or intermittently advanced toward the powder-particle-filled space S to the pressurizing position. The first air release gap is formed by the air that coexists with the granular material in the granular material filling space S when the granular material filled in the granular material filling space S is pressed by the upper and lower molds 13 and 14. To escape to the outside. The thickness dimension of the first air release gap is set to an appropriate value according to the specifications of the granular material to be filled in the granular material filling space S.

Each of the frame-type pressing means 25, 25
A hydraulic cylinder 27, a stopper 28, and a measuring tool 29 are provided. The hydraulic cylinder 27 includes a cylinder body 31 fixed to a base 38, a piston 32 fitted inside the cylinder body 31 so as to be able to advance and retreat, an output shaft 33 extending from both ends of the piston 32 and protruding from the cylinder body 27, and an operation shaft. And a pressing plate 35 attached to the end of the output shaft 33 to press the frame-type divided frame member 16 toward the granular material filling space S.

The stop member 28 is formed of a female screw which is screwed into a male screw formed on the operation shaft 34 protruding outside the cylinder main body 31, and abuts on the cylinder main body 31 to adjust the stop position of the output shaft 33. By doing so, the stop position of the frame-type split frame member 16 is set to the pre-pressing position (the position forming the first air release gap) and the post-pressing position (the first air release gap). (Closed or reduced position). Stopper 28
Is driven by a rotary drive device 36 (see FIG. 1) so that the stop position of the output shaft 33 can be changed. The rotation driving device 36 is provided with a driven gear 3 engraved on the outer periphery of the stopper 28.
6a and a driving gear 36b meshing with the driven gear 36a
And a servo motor 36c including a stepping motor for driving the driving gear 36b. By controlling the servo motor 36c, the stop position of the output shaft 33 can be selected. The measuring tool 29 is for measuring the position of the output shaft 33 that moves forward and backward. The control circuit of the servomotor 36c is provided with the output shaft 33 measured by the measuring tool 29.
In some cases, the feedback control is performed so as to eliminate or reduce the deviation between the current position of the target and the pre-pressing position or the post-pressing position that is the set stop position.

As shown in FIG. 2, each of the upper and lower mold pressing means 26, 26 constituting the pressing device 21 includes a hydraulic cylinder 39 and a measuring tool 40. The hydraulic cylinder 39 includes a cylinder body 41 fixed to the base 38,
Piston 42 internally fitted into cylinder body 41 so as to be able to advance and retreat
And the cylinder body 4 extending from both ends of the piston 42
An output shaft 43 and a measurement shaft 44 projecting from
The corresponding upper and lower dies 13, 14 are pressed toward the inside of the granular material filling space S by the tip of the output shaft 33. In some cases, the lower pressing means 26 for the lower mold is omitted, and the pressing is performed only by the upper pressing means 26 for the upper mold.

The pressing device 21 outputs a start signal and a stop signal to the frame-type pressing means 25, 25 and the vertical-type pressing means 26, 26 and supplies them to the respective hydraulic cylinders 27, 39. Hydraulic oil pressure value (ie,
A control device (not shown) for setting output values of the hydraulic cylinders 27 and 39) is provided. The control device adjusts the timing of approaching the upper and lower dies 13 and 14 and the two sets of frame member shifters 18 and 18 facing the frame type split frame members 16 and 16 as adjustment items at the time of molding. The circuit is configured so that the timing of approaching from the pressurizing position before forming the air release gap to the pressurizing position after closing or reducing the gap can be adjusted in time. Further, the control device is an upper and lower mold 1 which is an adjustment item at the time of mold removal.
When the members 3 and 14 are separated from each other, the timing and the two sets of frame member shifters 18 and 18 opposed to each other by the frame-type divided frame members 16 and 16 are set.
The circuit is configured so that the timing for separating the two can be adjusted in time. Further, the control device has a circuit configuration so that the pressure value of the oil supplied to each of the hydraulic cylinders 27 and 39 can be changed to an optimal value set in advance according to each timing. The control device includes two sets of frame member shifting tools 1.
In some cases, the section from the pre-pressing position to the post-pressing position for moving 8, 18 is divided into a plurality of sections so that the adjustment can be performed for each section.

The holding device 22 for temporarily holding the assembled molding die 11 is, as shown in FIGS.
Left and right pressing and holding for pressing and holding the left and right frame mold divided frame members 16 and 16 of the assembled molding die 11 guided by the mounting guides 47 and 47 to be described later and stopped at the holding position M. Means 48, 48 are provided. Pressing and holding means 48,
Each of the output shafts 48 includes an air cylinder or the like in which a cylinder body 48a is fixed to a base 38, and is capable of moving forward and backward.
A pressing and holding plate 48c is attached to the tip of 8b. The pressing and holding means 48 and 48 press and hold the frame-type divided frame members 16 and 16 when the output shafts 48b and 48b advance, and conversely, when the output shafts 48b and 48b retreat,
This pressing and holding is released.

The mold 11 before being held by the holding device 22 is temporarily assembled in a state as shown in FIG. This temporary assembly is performed manually or by an assembly device (not shown).
Done in The temporarily assembled molding die 11 is pressed by the output shafts 48b, 48b of the pressing and holding means 48, 48 so that the divided frame members 16, 16 for the frame die approach each other, as shown in FIG. Frame type divided frame members 17, 17
It is assembled in an integrated state by linking with. In the state where the assembled molding die 11 is held by the holding device 22, the filling of the granular material into the granular material filling space S and the fitting of the upper die 13 are performed. The upper mold 13 is inserted
This is performed manually or automatically by an upper mold insertion robot (not shown).

The transfer device 23 for transferring the molding die 11 from the holding position M of the holding device 22 to the molding position K of the pressing device 21 moves the bed 15 to the molding position K as shown in FIGS. There are left and right bed guides 47 and 47 extending in the front-rear direction for guiding, and transport means 46 such as an air cylinder that pushes the bed 15 while being guided by the left and right bed guides 47. I have.

Next, a method of molding a granular material according to the present invention will be described based on an embodiment using the molding die 11. The molding method according to the present embodiment includes a frame mold assembling step of assembling the frame mold 12 so as to surround the lower mold 14 with four frame mold divided frame members 16, 16, 17, 17 that can be joined and separated. A filling step of filling the granular material into the granular material filling space S inside the frame mold 12 and an upper mold 1 into the upper end opening of the frame mold 12.
An upper mold fitting step of assembling the molding die by inserting the molding die 3, a transporting step of transporting the assembled molding die 11 to a position of a molding step described later, and a dividing frame member 16, 16,
A molding step in which the upper and lower molds 13 and 14 approach each other while pressing the frame mold 12 so as not to separate the molds 17 and 17 so as to press and mold the granular material, and separate the upper and lower molds 13 and 14 from each other. The demolding step of releasing the pressing on the frame mold 12 to separate the frame-shaped divided frame members 16, 16, 17, 17 and demolding is performed in this order.

In the frame mold assembling step, as shown in FIG.
The lower step of the lower mold 14 placed on the bed 15
5a, and the lower frame 14 is divided by four frame-type split frame members 16, 16, 17, and 17 placed on the platform 15.
Are surrounded, so that four sets of shifting mechanisms 19 can be formed. This state is carried into the holding device 22, and the pressing means 48, 48 of the holding device 22 use the split frame member 1 for frame type.
The molds 6 and 16 are pressed so as to approach each other, and the molding die 11 is assembled as shown in FIG.

In the filling step and the upper mold inserting step, FIG.
As shown in the figure, in the state where the frame 12 of the molding die 11 is held by the holding device 22 so as not to be disassembled, the powder and granular material is filled into the powder and material filling space S inside the frame 12 and then The upper mold 13 is fitted into the upper end opening of the body filling space S. The fitted upper mold 13 is pressed by a pressing tool (not shown) composed of an air cylinder or the like of an upper mold fitting robot, thereby pressing the powder and granules to an appropriate degree. The degree of the pressurization is such that the solidified granular material does not lose its shape when being conveyed in the next conveying step.

In the transporting step, as shown in FIG. 1, the molding die 11 (shown by a two-dot chain line in the figure) released from holding by the holding device 22 is put together with the mat 15 and the mat guide 47. , 47 while being conveyed backward by the conveying means 23 and stopped at the molding position K of the pressing device 21. Stoppers 50, 50 are provided on the molding position K side,
The platform 15 can be stopped at a predetermined molding position K.

The molding step includes a first half pre-pressing step and a second half post-pressing step. The first pre-pressurizing step is performed in a state where the first air release gap is formed in the frame 12 of the molding die 11. The first air release gap is formed between the stop surfaces 17b, 18b of the adjacent frame-type divided frame members 16, 17 so as to extend in the vertical direction. The thickness of the air release gap (the distance from the stop surface 17b to the stop surface 18b) varies depending on the specifications of the granular material to be filled in the granular material filling space S, but is set in the range of 0.01 mm to 0.05 mm. Is done. In order to obtain the clearance for air release having the set dimension value, the stopper 2 of the frame-type pressing means 25, 25 is required.
By adjusting 8, 28, the frame-type split frame members 16, 16 are stopped at the pre-pressing position where the set first air release gap is obtained.

The molding die 11 conveyed to the molding position K
The frame mold 12 may be in a state where the adjacent frame mold divided frame members 16 and 17 are in close contact with each other and have no first air release gap. However, the granular material in the granular material filling space S is moved upward and downward by the upper and lower mold pressing means 26, 26.
When compressed by the pressurization of 3, 14, it moves in the X and Y axis directions and presses in the direction of retracting the frame-type divided frame members 16, 16, 17, 17. The pressed frame type split frame member 16,
16, 17, 17 retreat to the pre-pressing position where they come into contact with the frame-type pressing means 25, 25 of which the stop positions are adjusted, stop and form the first air release gap that has been set. The molding die 11 includes frame-type divided frame members 16, 16, 17, and 17.
As a result, a second air release gap is formed between the frame mold 12 and the upper and lower molds 13 and 14.

In the first half of the pre-pressurizing step, air coexisting with the granular material in the granular material filling space S is removed by the vertical pressing means 2.
When the pressurization of the upper and lower dies 13 and 14 by the upper and lower dies 6 and 26 progresses, the dies 13 and 14 are compressed and discharged to the outside of the molding die 11 through the first air release gap and the second air release gap. . The air existing near the center of the granular material filling space S which is separated from the second air release gap passes through the nearby first air release gap and is discharged to the outside. Degassing can be performed sufficiently as compared with the conventional molding method having no air release space. The value of the pressing force of the upper and lower dies 13 and 14 in this pre-pressing step is
For example, 50 to 150 Kg / cm ² is selected.

When the first half of the pre-pressing step is completed and the process proceeds to the second half of the post-pressing step, the upper and lower mold pressing means 26, 26
, The pressing force of the upper and lower dies 13 and 14 is gradually increased, and the stoppers 33 and 33 of the frame mold pressing means 25 and 25 are increased.
By gradually increasing the pressing force of the frame-type pressing means 25, 25 while adjusting the pressure, the frame-type divided frame member 1 stopped at the pre-pressing position where the first air release gap is formed.
6 and 16 are advanced toward the granular material filling space S together with the frame-type divided frame members 17 and 17 to gradually reduce the first air release gap formed in the frame die 12, After closing or reducing the air release gap, the air release gap is stopped at the pressurizing position. The frame type divided frame members 16 and 1 of the frame type 12
With the advance of 6,17,17, the frame mold 12 and the upper and lower molds 1
The gap for the second air release formed between the first and second air passages 3 and 14 also becomes gradually smaller.

The timing of approaching the upper and lower dies 13, 14 by gradually increasing the pressing force of the upper and lower mold pressing means 26, 26, and adjusting the timing of the stoppers 33, 33 of the frame pressing means 25, 25 while adjusting the frame mold. The pressing force of the pressing means 25, 25 is gradually increased so that the frame-shaped divided frame members 16, 16, 17, 17,
The timing for advancing 7 is set in accordance with molding conditions such as the properties of the granular material and the pressing force, and the pressing means 26, 26 for the upper and lower molds and the frame molds receiving the control signal issued from the control device. It is automatically controlled by the pressing means 25,25. In addition, the advancing of the frame-type divided frame members 16, 16 by the frame-type pressing means 25, 25 is performed continuously or intermittently according to the molding conditions, so that optimal pressure molding is obtained. As the value of the pressing force of the upper and lower dies 13 and 14 and the split frame members 16, 16, 17 and 17 in the pressing step, for example, 150 to 1250 kg / cm ² is selected.

In the second half post-pressurizing step, the first and second air release gaps are closed or made small so that the first and second air releasing gaps are pressurized at a higher pressure than the first half pre-pressurizing step. It is possible to press-mold at a high pressure without causing the pressurized powder to flow out of the first and second air escape gaps to the outside. Furthermore, in the latter half post-pressing step, the divided frame members 16 and 1 for the frame die which advance toward the post-pressing position around the filling body P during the press molding toward the granular material filling space S.
Since the pressure can be applied at 6, 17, and 17, the three-axis pressure applied to the packing material P, which is tightly tightened during the pressure molding and exhibits elastic characteristics, is made as close as possible. It becomes possible.

When the post-pressurizing step is completed in the latter half, the process proceeds to the demolding step. In the demolding step, the upper and lower mold pressing means 2
Upper and lower dies 13,1 while gradually reducing the pressing force of 6,26
4 and the pressing force of the frame-type pressing means 25, 25 is gradually reduced while the frame-type divided frame members 16, 1 are gradually reduced.
6, 17, 17 are retracted, and then the molding die 11 is disassembled to obtain a molded body. The timing of separating the upper and lower dies 13 and 14 and the timing of retracting the divided frame members 16, 16, 17, and 17 for the frame mold are set in a state in which the triaxial pressing stress generated in the molded body is approximated as much as possible. Pressing means 26 for upper and lower dies and pressing means 25 for frame for receiving a control signal issued from the control device so as to reduce
25 is automatically controlled.

In order to remove the molded body from the molding die 11 in the demolding process, the molded body is retracted by the transfer device 23 to the molding position K or the position of the holding device 22, and is extracted at the retracted position. This removal is performed manually or automatically.

The molding die 11 is provided with frame member shifters 18, 18 before and after each frame type divided frame member 16.
Moving mechanism 1 between adjacent frame-type divided frame members 16 and 17
9, two sets of frame-type pressing means 25, 2
5, the frame 12 is pressed. However, the molding die in the present invention is not limited to this, and although not shown, each of the divided frame members for the frame forming the frame is pressed by the frame pressing means 25. It is also possible to configure.

Upper and lower mold pressing means 26, 26 for pressing the upper and lower molds 13, 14 are provided with a measuring shaft 4 of a hydraulic cylinder 39 for controlling the stop positions of the molds 13, 14.
By changing the operation shaft 4 to an operation shaft and providing a stopper 28 (see FIG. 1) on the operation shaft, the structure may be the same as that of the frame-type pressing means 25. When the upper and lower dies 13 and 14 are stopped at predetermined positions, it is possible to obtain a molded body having a constant vertical dimension value. Further, the weight of the granular material to be filled in the granular material filling space S is made constant, and the upper and lower dies 13, 14 and the frame-type divided frame members 16, 1 in the post-pressing step.
By setting the stop positions of 6, 17 and 17 to predetermined positions, it is possible to obtain a molded body having high dimensional accuracy molded at a constant pressing force.

Further, the frame-type pressing means 25 and the vertical-type pressing means 26 are configured to pressurize hydraulically using a hydraulic cylinder. However, the present invention is not limited to this and is not shown. However, it is also possible to change to a screw jack structure in which the output shaft moves forward and backward by rotating the nut screwed to the output shaft made of bolts with an electric motor. In this case, by adjusting the rotation speed of the electric motor and operating the stop position of the output shaft, the divided frame members 16, 16, 17, 17 for the frame type and the upper and lower dies 13, 14 are formed.
Stop position can be controlled.

[0044]

According to the first aspect of the present invention, in the method for molding a granular material according to the present invention, in the pre-pressurizing step, the air in the filler is sufficiently discharged from the air release gap between the divided frame members for the frame to the outside. After discharging, the filled body can be molded under high pressure in the post-pressurizing step, so that a molded body without residual air can be obtained, and the yield of the molded body can be improved.

According to the method for molding a granular material according to the second aspect of the present invention, since the air can be discharged to the outside also from the second air release gap, the release of the air contained in the filler is ensured. In addition, it is possible to obtain a high-quality molded body which can be produced quickly and has no residual air.

According to the third aspect of the present invention, there is provided an apparatus for molding a granular material according to the present invention. The molding can be sufficiently discharged to the outside from the gap, and in the latter half of the pressure molding, the air release gap is closed or reduced to form the filling body at a high pressure to obtain a molded body without residual air. As a result, the yield of the molded body can be improved. Furthermore, since it is possible to approximate as much as possible the pressing stress in the triaxial direction generated in the filling body during the pressure molding, it is possible to obtain a molded body that is less likely to crack during firing in a subsequent step.

According to the fourth aspect of the present invention, since the stop position and the pressing force of the frame-shaped divided frame member can be easily changed, the production efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of a molding method and a molding apparatus according to the present invention, in which a molding apparatus is partially omitted.

FIG. 2 is a front sectional view showing the same embodiment and enlarging a main part of a molding apparatus during molding.

FIG. 3 is a partially sectional front view of the holding device, showing the embodiment, in a state of temporarily holding an integrated molding die;

FIG. 4 shows a frame form in an assembled state,
(A) is a plan view and (B) is a front sectional view.

FIG. 5 shows a mold in a separated state,
(A) is a plan view and (B) is a front sectional view.

6A and 6B show a conventional molding method, in which FIG. 6A is a cross-sectional plan view during molding, and FIG. 6B is a cross-sectional plan view during demolding.

7A is a sectional view taken along line EE in FIG. 6A, and FIG. 7B is a sectional view taken along line FF in FIG. 6B.

[Explanation of symbols]

S: powder and particle filling space, 12: frame type, 16, 17: divided frame member, 21: pressing device, 22: holding device, 23: transport device, 25: pressing device for frame type, 26: pressing for vertical type means,
27: Hydraulic cylinder, 28: Stopper

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B30B 11/00 B30B 11/00 Z

Claims (4)

[Claims] 1. A frame mold assembling step of assembling a frame with a plurality of separable frame-type split frame members, and a filling step of filling a granular material into a granular material filling space inside the frame mold. A molding step of molding the filled powder by pressing the upper and lower molds with pressure, wherein the molding step is for releasing air between adjacent frame-type divided frame members. A pre-pressurizing step performed in a state in which a gap is formed, and a post-pressing step performed in a state in which the gap is closed or reduced after the pre-pressing step. A method for molding a granular material, wherein a post-pressing step is higher than a pressing step. 2. The pre-pressurizing step is performed in a state in which a second air release gap is formed between the upper and lower molds and the frame mold that have entered the granular material filling space. A method for molding a powder or granule according to claim 1. 3. A plurality of separable frame-type frame members for assembling a frame forming a particulate material filling space inside, and upper and lower parts which can be disposed so as to cover the particulate material filling space from above and below. , A frame-type pressing means for pressing the divided frame member for the frame toward the powder-particle-filled space, and pressing one or both of the upper and lower dies toward the powder-particle-filled space. In the apparatus for molding a granular material having an upper and lower mold pressing means, when the frame mold pressing means presses the upper and lower molds with the upper and lower mold pressing means, the frame mold dividing frame member is The space between the divided frame members for adjacent frame molds is moved forward from the pre-pressing position for forming the air release gap to the post-pressing position for closing or reducing the gap toward the powder and granular material filling space. An apparatus for molding a granular material. 4. The frame mold pressing means projects an output shaft and an operating shaft extending from both ends of a piston which is fitted to a fixed cylinder body so as to be able to advance and retreat, from the cylinder body, and the output shaft uses the output shaft. A hydraulic cylinder adapted to press the frame-type split frame member, and a stopper which is screwed to the operation shaft outside the cylinder body and abuts against the cylinder body to adjust a stop position of the output shaft. 4. The powder particle according to claim 3, wherein by rotating the stopper, the frame-type split frame member pressed by the output shaft can be advanced from the pre-pressing position to the post-pressing position. 5. Body molding equipment.