CN1649722A - Powder compacting method and powder compacting system - Google Patents

Abstract

This invention has been realized in order to obtain green compacts of a fixed height by pressure molding of material powder with a fixed gap between upper and lower punches. A powder compacting method of this invention performs a punch driving step wherein, after filling material powder in a cavity, the material powder filled in the cavity is pressure molded by using an upper punch and a lower punch, said punch driving step comprising a primary driving step of driving either one of the punches until the thickness of the cavity formed between the upper and lower punches becomes slightly greater than a target molding thickness, and a secondary driving step of measuring a gap between the upper and lower punches and driving either one of the punches while controlling it until the measured value reaches the target molding thickness.

Description

Powder forming method and powder forming device

technical field

The present invention relates to a powder forming method and a powder forming device for press forming raw material powder.

Background technique

In the past, there was a so-called machine tool that drives the upper punch by means of a crank, etc., as a molding device for press-molding the raw material powder filled in the cavity between the upper punch and the lower punch to form a green compact. press.

An example of such a mechanical press (powder molding device) 110 is shown in FIG. 8 . This mechanical press 110 is a device for forming a cylindrical powder compact, and its structure is: a die 112 for forming the outer peripheral surface of the compact, a cylindrical mandrel 113 for forming the inner peripheral surface, and a molding upper. A cylindrical upper punch 114 for an end face is vertically movable and held on a frame 111, and a cylindrical lower punch 115 for molding the lower end face of the green compact is fixed to the frame 111.

In addition, FIG. 8 shows a mechanical press 110 using the so-called withdrawal method in which the raw material powder is pressed when the upper punch 114 is lowered by a predetermined distance. , then the die 112 and the mandrel 113 and the upper punch 114 begin to descend integrally. If the press molding of the raw material powder is completed, the upper punch 114 rises, and the die 112 and the mandrel 113 further descend and pull out the compacted powder .

Up and down movement of the upper punch 114 is performed by a crank mechanism 116 shown in FIG. 9 . The crank mechanism 116 can be set such that when the upper punch 114 is lowered to the bottom dead center, the distance between the upper and lower punches 114 and 115 becomes the thickness of the green compact to be obtained. That is, since the movement of the upper punch 114 is mechanically restricted and lowered to a predetermined position relative to the fixed lower punch 115, the mechanical press 110 is characterized in that it is easy to obtain green compacts of a certain thickness.

However, due to the extension and deflection of the frame 111 holding each component, the variation in the filling amount of the raw material powder, etc., although the upper punch 114 is lowered to the bottom dead center, the interval between the upper and lower punches may not be at a specified value. As a result, A green compact having a predetermined thickness cannot be obtained, and thus the thickness of the green compact varies.

The present invention was made in view of the above-mentioned problems, and an object of the present invention is to obtain a green compact having a constant thickness by performing press molding with a constant interval between upper and lower punches.

Contents of the invention

In order to solve the above-mentioned problems, the powder molding method of the present invention is a powder molding method in which a punch driving step is performed after a filling step of filling raw material powder into the cavity. The raw material powder inside is press-formed between the upper punch and the lower punch; it is characterized in that the punch driving process has: drive either punch until the thickness of the cavity formed between the upper and lower punches becomes the ratio forming The primary driving process in which the target thickness is slightly larger, and the secondary driving process of measuring the distance between the upper and lower punches and driving one of the punches while controlling until the measured value becomes the above-mentioned forming target thickness.

Or, it is characterized in that the punch driving step of forming the raw material powder in the cavity has: a driving step of driving any one punch to make the upper and lower punches approach, and a driving step to make the interval between the upper and lower punches larger than When forming the target thickness, at least one of the upper and lower punches is driven while controlling until the distance between the upper and lower punches becomes the forming target thickness.

In this powder molding method, either one of the upper and lower punches may be fixed in the primary driving process to drive the other punch, and the one punch fixed in the primary driving process may be driven and fixed in the secondary driving process. The other side punches. Alternatively, one punch may be driven and the other punch fixed in two steps.

According to this method, since the raw material powder is press-molded to the target thickness of the molding while measuring the distance between the upper and lower punches, even if the frame is stretched or deflected, the distance between the upper and lower punches becomes a predetermined distance, and a certain thickness can be obtained. thick pressed powder.

Furthermore, if the interval between the upper and lower punches is set slightly larger than the target thickness of forming in the primary driving process, the interval between the upper and lower punches must be adjusted in the secondary driving process. As a result, a green compact having a desired thickness can be reliably molded.

Moreover, when the interval between the upper and lower punches is set to the molding target thickness in one driving process, even if the interval between the upper and lower punches does not become the desired value due to the deflection of the device in one driving process, it can be Minor adjustments are made to the interval between the upper and lower punches in the secondary drive process. As a result, the thickness of the green compact can be reliably reduced to a predetermined value or less.

Furthermore, it is preferable that in the filling process, the configuration is such that after the advance step of advancing the shoe box, which is slidably arranged on the upper surface of the die and has an open lower surface, onto the cavity, the shoe box Retraction process of retreating from the cavity, and during the retraction process, the lower punch is raised relative to the die, and a part of the raw material powder filled in the cavity is pushed to the die, and the retracted shoe box is used A part of the raw material powder pushed onto the die is scraped off, and at the end of the retraction step, the relative position of the lower punch relative to the die is returned to the position before the retraction step.

That is, since the density of the raw material powder to be filled in the cavity is different before and after the advancing and retreating direction of the shoe box, the depth of the cavity is changed by driving the lower punch up and down in conjunction with the filling process, so that the depth of the cavity is changed. The volume of the raw material powder is different in the forward and backward direction of the shoe box, and the amount of the raw material powder filled in the cavity can be made uniform. Therefore, since the filling amount of the raw material powder in the entire cavity becomes uniform, by pressing with a constant interval between the upper and lower punches, it is possible to stably manufacture a green compact having uniform density and thickness as a whole.

In addition, the powder molding device of the present invention is characterized in that it is a powder molding device for press-molding the raw material powder filled in the cavity between the upper punch and the lower punch, and includes: driving either one of the upper and lower punches The upper and lower primary driving device, the secondary driving device for fine-tuning the vertical position of either of the upper and lower punches, the measuring mechanism used to find the interval between the upper and lower punches, feedback the measurement results of the measuring mechanism and control the secondary driving device The control unit until the measurement result becomes the target value.

According to the present invention, since the distance between the upper and lower punches can be measured and the raw material powder can be press-molded to the target thickness for forming, even if the frame is stretched or deflected, the upper and lower punches can be at a predetermined distance, and a press of a certain thickness can be obtained. Powder.

In this powder molding apparatus, one of the upper and lower punches is driven by a primary drive device and the other is driven by a secondary drive device. Alternatively, only one of the punches may be driven by the primary drive device and the secondary drive device.

At this time, if the upper punch is driven by the secondary drive device, it is easy to form a device in which the lower punch is fixed and the die can move up and down. powder forming device.

In addition, if the configuration in which the lower punch is driven by the secondary driving device is adopted, the following process can be performed by using the secondary driving device, that is, when the shoe box is used for filling, the lower punch is driven to make the powder in the cavity Since the filling amount is uniform, the equipment can be simplified.

Description of drawings

Fig. 1 is a cross-sectional view showing a main part of a powder molding apparatus according to an embodiment of the present invention, and is a diagram illustrating a filling process;

FIG. 2 is a diagram showing a step of raising a lower punch in a step of retracting a shoe box in the powder molding apparatus shown in FIG. 1;

Fig. 3 is a diagram showing a state in which the lower punch is lowered to complete filling of the raw material powder in the powder forming device shown in Fig. 1;

Fig. 4A is a diagram for explaining a powder molding method according to an embodiment of the present invention, and is a cross-sectional view showing a mechanical driving process for lowering the upper punch to the bottom dead center;

4B is a diagram for explaining a powder molding method according to an embodiment of the present invention, and is a cross-sectional view showing an adjustment process of raising the lower punch until the thickness of the cavity becomes the molding target thickness;

4C is a diagram for explaining a powder molding method according to an embodiment of the present invention, and is a cross-sectional view showing a step of pulling out a molded green compact from a die;

Fig. 5 is an operation diagram showing the operation of upper and lower punches and shoe boxes in each process of powder molding;

Fig. 6 is a cross-sectional view showing main parts of a powder compacting device according to another embodiment of the present invention;

Fig. 7 is a working process diagram showing the powder molding method of the present invention using the powder molding device shown in Fig. 6;

Fig. 8 is a schematic diagram showing the outline of a conventional powder molding device;

Fig. 9 is a schematic diagram showing an example of an upper punch driving mechanism in a powder forming apparatus;

Specific implementation form

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 to 4 show the main parts of the powder molding device 1 according to the first embodiment of the present invention. The reference number 10 is an upper punch, the reference number 20 is a lower punch, the reference number 30 is a mandrel, the reference number 40 is a die, and the reference number 50 is a slide. In the shoe box, reference numeral 60 is a measuring mechanism for measuring the distance L between the upper and lower punches (linear scale for bottom dead center correction), and P is the raw material powder.

A forming hole 40 a is provided in the die 40 , and the mandrel 30 is disposed at the center of the forming hole 40 a. The cylindrical space formed between the forming hole 40a and the mandrel 30 is closed by a cylindrical lower punch 20 fitted from below and a cylindrical upper punch 10 fitted from above, and formed Cavity C. The raw material powder P is pressurized in this cavity C, and the green compact Z following the shape of the cavity C is molded.

The shoe box 50 that fills the cavity C with raw material powder P is formed in a box shape with an open lower surface, and slides back and forth (left and right in the figure) in a state where the lower surface is in contact with the upper surface of the die 40 . The raw material powder P is supplied into the shoe box 50 from a hopper not shown in the figure, and by advancing to the position shown in FIG. C, while filling.

The upper punch 10 is fixed to an upper punch holding member 10A vertically movable with respect to the chassis 100 via the frame 70 , and is a cylindrical member capable of vertically moving integrally with the upper punch holding member 10A. The upper punch holding member 10A to which the upper punch 10 is fixed is mechanically driven up and down by a mechanism (primary drive device) such as a crank mechanism, a crank-link press, or a cam mechanism shown in FIG. 8 , for example. In this way, by lowering the upper punch 10 to the bottom dead center, the raw material powder P filled in the cavity C can be pressurized.

The lower punch 20 is a cylindrical member fixed on the lower punch holding part 20A, and can be connected to the lower punch holding part 20A under the action of the piston 81 of the fluid pressure cylinder (secondary driving device) 80 fixed on the chassis 100. Move up and down in one piece. Between the lower punch 20 (lower punch holding member 20A) and the chassis 100 , a filling amount correction linear scale 61 for detecting the position of the lower punch 20 relative to the chassis 100 is attached. The piston 81 , that is, the lower punch 20 can be moved to an arbitrary position by controlling the flow rate of the fluid pressure cylinder 80 by the control unit 90 receiving a detection signal from the filling amount correcting linear scale 61 .

A linear scale (measuring mechanism) 60 for bottom dead point correction is installed between the upper punch holding member 10A and the lower punch holding member 20A, and measures the distance between the upper punch holding member 10A and the lower punch holding member 20A. That is, the measured value obtained by measuring the distance between the upper punch 10 and the lower punch 20 is output as a signal. A target value is set in advance in the control unit 90 to which this signal is input, and the flow rate of the fluid pressure cylinder 80 can be controlled so that the measured value becomes the target value. The target value is a value such that the thickness of the cavity C between the upper punch 10 and the lower punch 20 becomes a forming target thickness.

In addition, a shoe box position detection signal, which is output from a shoe box position detection sensor not shown and indicates the position of the shoe box 50 , is also input to the control unit 90 .

Next, a powder molding method using the powder molding apparatus configured as above will be described with reference to FIG. 5 . 5, the horizontal axis represents the angle of the crank that mechanically drives the upper punch 10, the vertical axis represents the positions of the upper and lower punches and the shoe box, and the upper part of the vertical axis is the shoe box 50. The forward side and above the upper and lower punches.

In press forming, first, the upper punch 10, the lower punch 20, and the die 40 are respectively arranged at initial positions.

【Filling process】

The shoe box 50 is advanced (advancing step), as shown in FIG. 1, is opened on the upper surface of the cavity C (FIG. 5(a)), and the raw material powder P is filled. At this time, the shoe box 50 advances from the rear (the right side in FIG. 1 ) to the front (the left side in FIG. 1 ) and moves to the position shown in FIG. 1 , so that it starts to open on the rear side of the cavity C. , and then open above the front side. Therefore, since the shoe box 50 is opened on the rear side for a relatively long time, and the raw material powder P is supplied to the cavity C, the density of the raw material powder P filled is higher toward the rear side.

Next, as shown in FIG. 2 , the shoe box 50 is retracted to retract from the cavity C (retraction step), and the lower punch 20 is raised relative to the die 40 at the beginning of the retraction step ( FIG. 5( b )), That is, the shoe box 50 is retracted, and the excess raw material powder P placed on the die 40 and the mandrel 30 is scraped off by the front wall of the shoe box 50, and the wall is retracted farther than the front of the cavity C. The lower punch 20 is raised after the side leaning to the rear, thereby pushing a part of the raw material powder P filled in the rear side of the cavity C to the top of the die 40 and scraped off by the shoe box 50 at the same time. The amount of raw material powder P filled in the cavity C is corrected. Thus, the volume of the raw material powder P increases at the front side of the cavity C, and decreases at the rear side of the cavity C. As shown in FIG.

Furthermore, as shown in FIG. 3 , after the shoe box 50 is completely retracted from the cavity C, the raised lower punch 20 is lowered relative to the die 40 to return to the initial position ( FIG. 5( c )). Therefore, the raw material powder P pushed to the front side of the cavity C on the die 40 returns to the cavity C (inside the die 40 ), and the raw material powder P is filled into the mold so that the filling height is higher on the front side and lower on the rear side. In cavity C.

That is, since the raw material powder is filled into the cavity by natural fall from the shoe box, the density is relatively high at the rear side of the cavity where the shoe box has been open for a long time. Therefore, if the overall filling is at the same height, the higher the density, the higher the amount of raw material powder filled at the rear side of the cavity, and the green compact obtained by press molding the raw material powder P in this filled state Density is not uniform.

On the other hand, in this embodiment, the filling height of the raw material powder is high on the low-density front side and low on the high-density rear side to eliminate the unevenness of the filling amount in the advancing and retreating direction of the shoe box, thereby The raw material powder P is uniformly filled in the entire cavity C.

【Punch driving process】

4A to 4C show the process of press forming by driving the upper and lower punches.

(Primary drive process)

First, as shown in FIG. 4A , with the lower punch 20 fixed, the upper punch 10 is lowered to the bottom dead center (mechanical movement boundary position) to compress the raw material powder P in the cavity C. In this device, although it is designed that the upper punch 10 descends to the double-dot dash line position (ideal bottom dead center) shown in Fig. 5 (d), due to the deflection of the device, etc. The position of the solid line shown in Fig. 5(e).

The (design) ideal bottom dead center of the upper punch 10 is set so that a mold having a thickness greater than the target thickness of the green compact, for example, about 1 mm, is formed between the lower punch 20 fixed at the initial position. Cavity C. That is, even when the device does not bend or stretch and the upper punch 10 is lowered to the ideal bottom dead center, the thickness of the cavity C will be larger than the molding target thickness, and the thickness will not be smaller than the molding target thickness. compressed powder.

(Secondary drive process)

Next, as shown in FIG. 4B , the crank of the mechanically driven upper punch 10 is stopped, and with the upper punch 10 fixed at the bottom dead center, the fluid pressure cylinder 80 is driven to raise the lower punch 20 from the initial position until The thickness of the cavity C becomes the molding target thickness ( FIG. 5( g )). The movement of the lower punch 20 at this time is performed by feeding back the measured value of the linear scale 60 for correcting the bottom dead point.

That is, the control unit 90 that receives the detection signal from the filling amount correction linear scale 61 controls the flow rate of the fluid pressure cylinder 80, and uses the bottom dead center correction linear scale 60 to measure the distance between the upper and lower punches, and uses the control unit 90 to control the flow rate of the fluid pressure cylinder 80. The driving of the pressure cylinder 80 raises the lower punch 20 until the measured value reaches the forming target thickness.

At this time, although the upper punch 10 may be slightly pushed up due to the lower punch 20 rising (Fig. 5(e')), the lower punch 20 is raised by feeding back the measured value of the distance between the upper and lower punches , so the lower punch 20 is driven until the thickness of the cavity C reaches the forming target thickness and corrects the insufficient part caused by the lowering of the upper punch 10, so that the thickness of the compact can reach the target value.

Then, as shown in FIG. 4C , the upper punch 10 is raised ( FIG. 5( h )), and the mandrel 30 and the die 40 are lowered relative to the lower punch 20 , and the formed compact Z is pulled out from the die 40 . . In addition, the lower punch 20 raised in the secondary driving step returns to the initial position ( FIG. 5( i )), and becomes a state in preparation for forming the next green compact.

As described above, it is possible to obtain a green compact Z having a uniform overall density and being molded to a molding target thickness.

In addition, the various shapes and combinations of the components shown in the above-mentioned embodiments are examples, and various changes can be made in accordance with design requirements and the like without departing from the gist of the present invention. In the illustrated example, the upper punch 10 is mechanically driven in the primary driving process, and the lower punch 20 is driven by the fluid pressure cylinder 80 in the secondary driving process, but it can also be reversed. A configuration in which the lower punch is mechanically driven in the process and the upper punch is driven in the secondary drive process. In addition, in the above embodiment, the fluid pressure cylinder 80 is used as the secondary driving device, but various driving devices such as an electric servo motor may also be used.

In addition, in the above-mentioned embodiment, although the thickness of the cavity C formed in one driving process is made larger than the target thickness of forming, since the thickness of the cavity C only needs to be set at the position of the upper and lower punches in one driving process, As for the molding target thickness, the secondary driving process can be performed only when the thickness of the cavity does not reach the molding target thickness due to device deflection, etc., so that the control of the device can be simplified. With this molding method, if the thickness of the cavity is smaller than the molding target thickness in one driving process, a green compact with a thickness smaller than the desired thickness will be molded. However, if the thickness of the compact is below a certain value, for example, the precision It is valid in cases where the above is sufficient.

The second embodiment of the present invention will be described below with reference to FIG. 6 and FIG. 7 . In the CNC pressing device 201 shown in FIG. 6, the die 205 having the cavity C filled with the raw material powder P and the upper punch 208 are driven up and down respectively, and the lower punch 209 is always fixed.

The die 205 is attached to the lower slider 203 sliding in the lower guide 202 via the lower ram 204, and moves up and down driven by a driving mechanism (not shown) such as a ball screw mechanism. The lower punch 209 fixed to the fixing plate 213 is arranged below the die 205 so as to be fitted into the cavity C from below.

An upper punch 208 capable of entering and exiting the cavity C is coaxially arranged above the lower punch 209 to face the lower punch 209 . The upper punch 208 is installed on the upper guide 210 sliding in the upper slider 206 via the upper punch 207 , wherein the upper punch is composed of a hydraulic piston 222 and a hydraulic cylinder 201 on which an upper punch plate 223 is installed. The upper slider 206 is connected to a crankshaft 212 via a link mechanism 211, and the crankshaft 212 is rotated by a drive motor M (primary drive device). The drive motor M is a servo motor whose drive and stop are controlled according to a program stored in the computer (control unit) 220 .

The upper ram 207 has a hydraulic cylinder 221 fixed on the upper guide 210 and a hydraulic piston 222 installed on the upper punch plate 223 . A hydraulic pressure supply port 221 a is provided in the hydraulic cylinder 221 , and hydraulic pressure is supplied from a hydraulic device 26 (secondary drive device) through a hydraulic pressure supply pipe 25 connected thereto. Hydraulic control is performed through a hydraulic servo valve 224 provided on the hydraulic supply pipe 25 and driven by a computer 220 .

That is, in the upper ram 207 , the whole is driven up and down by the drive motor (primary drive device) M, and the hydraulic piston 222 is driven up and down by the hydraulic device (secondary drive device) 226 .

Moreover, on the CNC pressure device 201, between the upper punch plate 223 on which the upper punch 208 is fixed and the fixed wrench 213 on which the lower punch 209 is fixed is provided for measuring the distance between the upper punch plate 223 and the fixed wrench 213. The linear scale (measuring mechanism) 214 of the interval. The measured value of the linear scale 214 is input to the computer 220, and the computer 220 having input the measured value outputs a drive signal of the drive motor M and a drive signal of the hydraulic servo valve 224 according to a program.

Referring to FIG. 7, a powder molding method using the CNC press device 201 configured as described above will be described. 7, the horizontal axis represents the rotation angle of the crankshaft 212 that mechanically drives the upper punch 208, and the vertical axis represents the vertical direction of the upper and lower punches 208, 209 and the die 205.

【Punch driving process】

First, in press forming, the upper punch 208, the lower punch 209, and the die 205 are respectively arranged at initial positions.

(Primary drive process)

First, with the lower punch 209 and the die 205(a) fixed, the upper ram 207 is lowered to the bottom dead center (mechanical movement boundary position) D, and the cavity C filled with the raw material powder P is closed (i ).

(Secondary drive process)

When the crank angle reaches 180° and the upper ram 207 reaches the bottom dead center D, the program of the computer 220 stops the drive motor M that mechanically drives the upper ram 207, and the upper ram 207 that descends by lowering the upper ram 207 stops. Punch 208 stops falling (ii). Then, when the upper ram 207 stops descending, the hydraulic servo valve 224 is driven to supply hydraulic pressure to the hydraulic cylinder 221, so that the hydraulic piston 222, that is, the upper punch 208, descends until the measured value of the linear scale 214 reaches the set value (cavity The thickness of C becomes the value of the forming target thickness) (iii). Then, while the upper punch 208 is lowered by hydraulic pressure, by lowering the die 205 by about half (b) of the lower stroke of the upper punch 208, the raw material powder P in the cavity C is pushed from the upper and lower sides, and is subjected to pressure. Uniform pressing force acts, thereby being compressed into a uniform density in the up and down direction.

Then, if the measured value of the linear scale 214 becomes the set value, the hydraulic servo valve 224 is controlled by the computer 220 to make the hydraulic piston 222 rise, so that the upper punch 208 rises, and the operation of the drive motor M is started again to make the upper punch 208 rise. It is raised together with the upper ram 207 (iv), and the die 205 is lowered (c). As a result, the product (green compact) _Z0 molded to a molding target thickness is pulled out from the die 205 (cavity C) and placed on the lower punch 209 .

As described above, the green compact Z ₀ molded to the thickness targeted for molding can be obtained.

In addition, the various shapes and combinations of the components shown in the above-mentioned embodiments are examples, and various changes can be made in accordance with design requirements and the like without departing from the gist of the present invention. In the illustrated example, although the lower punch 209 is fixed and the upper punch 208 is driven in the primary driving process and the secondary driving process, it is also possible to drive the lower punch in two driving processes and fix the upper punch. The composition of the punch.

In addition, in the above-mentioned embodiment, although the thickness of the cavity formed in one driving process is made larger than the target thickness for forming, since the upper and lower punch positions are set in one driving process, the thickness of the cavity is set to be the thickness of the forming cavity. For the target thickness, the secondary drive process can be performed only when the thickness of the cavity does not reach the molding target thickness due to device deflection, etc., so the control of the device can be simplified and the manufacturing time can be shortened. With this molding method, if the thickness of the cavity is smaller than the molding target thickness in one driving process, a green compact with a thickness smaller than the desired thickness will be molded. However, if the thickness of the compact is below a certain value, for example, the precision It is valid in cases where the above is sufficient.

As described above, according to the present invention, since the raw material powder is press-molded to the molding target thickness while measuring the distance between the upper and lower punches, even if the filling amount of the raw material powder varies, or the frame is stretched or deflected, the A green compact with a target thickness can be stably produced.

By filling the entire cavity with a uniform amount of raw material powder and punching with a constant interval between the upper and lower punches, it is possible to stably manufacture compacts with uniform overall thickness and density.

Claims (12)

1, a kind of powder forming method, be behind the filling work procedure that material powder is filled in the die cavity, carry out the powder forming method that drift drives operation, wherein, to drive operation be to be filled into material powder in this die cavity carries out press molding between upper punch and low punch operation to drift;

Above-mentioned drift driving operation has: the thickness of driving either party's drift formed die cavity up between last low punch becomes the once driving operation of the state bigger slightly than shaping target thickness and measures the interval and the limit of going up low punch and control limit driving either party drift becomes above-mentioned shaping target thickness up to described measured value secondary driving operation.

2, a kind of powder forming method, be behind the filling work procedure that material powder is filled in the die cavity, carry out the powder forming method that drift drives operation, wherein, to drive operation be to be filled into material powder in this die cavity carries out press molding between upper punch and low punch operation to drift;

Above-mentioned drift drives operation to have: drive either party's drift and make the approaching once driving operation of low punch and control the limit and drive the above-mentioned either party at least who goes up low punch becomes the shaping target thickness up to above-mentioned interval of going up low punch secondary driving operation by above-mentioned when once driving operation and making above-mentioned interval of going up low punch greater than the shaping target thickness, limit.

3, powder forming method as claimed in claim 1, drive in the operation at above-mentioned drift, above-mentioned once drive operation and above-mentioned secondary drive drive in the operation above-mentioned on either party's drift in the low punch, drive in the operation fixedly the opposing party's drift at above-mentioned operation and the above-mentioned secondary of once driving.

4, powder forming method as claimed in claim 2, drive in the operation at above-mentioned drift, above-mentioned once drive operation and above-mentioned secondary drive drive in the operation above-mentioned on either party's drift in the low punch, drive in the operation fixedly the opposing party's drift at above-mentioned operation and the above-mentioned secondary of once driving.

5, powder forming method as claimed in claim 1 drives in the operation at above-mentioned drift, above-mentioned once drive fix in the operation above-mentioned on either party's drift in the low punch, and drive at above-mentioned secondary and to drive this drift in the operation; At the above-mentioned drift that drives the opposing party in the operation that once drives, and in above-mentioned secondary driving operation, fix this drift.

6, powder forming method as claimed in claim 2 drives in the operation at above-mentioned drift, above-mentioned once drive fix in the operation above-mentioned on either party's drift in the low punch, and drive at above-mentioned secondary and to drive this drift in the operation; At the above-mentioned drift that drives the opposing party in the operation that once drives, and in above-mentioned secondary driving operation, fix this drift.

7, as each described powder forming method of claim 1～6, above-mentioned filling work procedure is constituted, on making the upper surface that is disposed at above-mentioned punch die slidably and the open piston shoes box of lower surface advance to after the operation of advancing on the die cavity, make above-mentioned piston shoes box keep out of the way operation from what above-mentioned die cavity was kept out of the way, and in above-mentioned process of keeping out of the way operation, above-mentioned low punch is risen relatively with respect to above-mentioned punch die, and the part that will be filled into the material powder in the above-mentioned die cavity boosts on the above-mentioned punch die, the above-mentioned piston shoes box that utilization is kept out of the way scrapes off and is pushed a part that plays the material powder on this punch die, in the above-mentioned operation of keeping out of the way when finishing, above-mentioned low punch is turned back on the position of keeping out of the way before the operation with respect to the relative position of above-mentioned punch die.

8, a kind of powder forming device is to be filled into material powder in the die cavity carries out press molding between upper punch and low punch powder forming device, comprising:

Drive above-mentioned either party's drive unit up and down of going up low punch,

The secondary drive unit that the above-mentioned upper-lower position of going up the either party of low punch is finely tuned,

Be used for obtaining the above-mentioned measuring mechanism of going up the interval of low punch,

Feed back the measurement result of this measuring mechanism and control above-mentioned secondary drive unit becomes desired value up to this measurement result control part.

9, powder forming device as claimed in claim 8, an above-mentioned side who goes up in the low punch is driven by an above-mentioned drive unit and above-mentioned secondary drive unit.

10, powder forming device as claimed in claim 8, an above-mentioned side who goes up in the low punch is driven by an above-mentioned drive unit, and the opposing party is driven by above-mentioned secondary drive unit.

11, as each described powder forming device of claim 8～10, above-mentioned upper punch is driven by above-mentioned secondary drive unit.

12, as each described powder forming device of claim 8～10, above-mentioned low punch is driven by above-mentioned secondary drive unit.

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