JP2008266752A - Powder molding product manufacturing method and powder molding apparatus - Google Patents

Abstract

A method for producing a powder molded product capable of reducing the inter-product variation in the size of a powder sintered product after being sintered by reducing the inter-product variation in the density of the powder molded product to be compacted. To provide a powder molding apparatus.
A powder molding apparatus includes a die having a filling portion A filled with a material powder, a lower punch, and an upper punch supported so as to be movable back and forth with respect to the die. A first pressurizing control means for advancing and pressurizing the upper punch 31 and the lower punch 21 to respective predetermined positions of the die 11, and the upper punch 31 and the lower punch 21 being respectively predetermined. A second pressurizing control means for forming at least one of the upper punch 31 and the lower punch 21 after reaching the position until the punch reaches a predetermined pressing force; And
[Selection] Figure 1

Description

  The present invention relates to a method for producing a powder molded product and a powder molding apparatus.

  As is well known, in the fields of automobile parts, electronic parts, cutting tools, etc., powder sintering is performed by forming ceramic powders such as metal powders and alumina into powder molded products and sintering the powder molded products. The powder metallurgy sintering method for manufacturing products made of products is widely used.

  The powder metallurgy sintering method is a powder forming apparatus including a die, a lower punch that defines a filling portion together with the die, and an upper punch that is supported so as to be able to advance and retreat toward the filling portion. The material powder is filled, and the material powder is pressed by an upper punch and a lower punch to form a powder molded product. Then, the powder molded product is sintered under predetermined conditions to produce a powder sintered product.

The powder molded product that has been compacted by the above powder molding apparatus is greatly shrunk when sintered, and the magnitude of the shrinkage is greatly influenced by the density of the powder molded product. It is desirable to suppress the density variation and to shrink during sintering.
Thus, when molding the material powder by moving the lower punch relative to the die, the material powder in the filling portion is pressed from below by fixing the die and moving the lower punch forward relative to the die. For example, as shown in Patent Document 2, for example, as shown in Patent Document 2, the die fixing method as shown in Patent Document 1 and the lower punch are fixed and the die descends to relatively compact the material powder in the filling portion from below. Withdrawal method has been put into practical use.
Japanese Patent Laid-Open No. 1-181997 JP-A-5-92299

  However, even if the powder molded product is compacted by such a method, the density of the powder molded product will differ if the material powder filled in the filling portion varies in weight and is molded to the same height. As a result, there is a problem that the size of the powder sintered product after sintering the powder molded product varies from product to product.

  The present invention has been made in consideration of such circumstances, and between the products of the size of the powder sintered product after being sintered by reducing the inter-product variation in the density of the powder molded product to be compacted. It is an object of the present invention to provide a method for producing a powder molded product and a powder molding apparatus capable of suppressing variation.

In order to achieve the above object, the present invention proposes the following means.
The invention described in claim 1 includes a die formed with a filling portion filled with a material powder, a lower punch attached to the die so as to be relatively movable, and defining the filling portion together with the die, A method for producing a powder molded product by a powder molding apparatus, comprising an upper punch disposed above the die and supported so as to be movable forward and backward with respect to the die, wherein the upper punch and the lower punch are After the upper punch and the lower punch reach the predetermined position, at least one of the upper punch and the lower punch is pressed against the pressing force of the punch. It is characterized in that the molding is advanced until it reaches a predetermined value.

  The invention described in claim 2 includes a die formed with a filling portion filled with a material powder, a lower punch attached to the die so as to be relatively movable, and defining the filling portion together with the die, A powder forming apparatus including an upper punch disposed above the die and supported to be movable back and forth with respect to the die, wherein the upper punch and the lower punch are advanced to respective predetermined positions of the die. After the first pressurizing control means and the upper punch and the lower punch reach their predetermined positions, at least one of the upper punch and the lower punch is advanced until the punch reaches a predetermined pressure force. And a second pressurizing control means for molding.

According to the powder molding method and the powder molding apparatus according to the present invention, the upper punch and the lower punch are relatively advanced to respective predetermined positions of the die and compacted to near the final dimension as a powder molded product, and thereafter Since at least one of the upper punch and the lower punch is advanced until a predetermined pressing force is reached, a powder molded product having a substantially constant density is produced regardless of the weight of the material powder to be filled. As a result, it is possible to reduce the variation in density between the products of the powder molded product.
Therefore, the dimensional variation between products when a powder molded product is sintered into a powder sintered product can be suppressed small.

  According to a third aspect of the present invention, there is provided the powder molding apparatus according to the second aspect of the present invention, comprising a CNC position control unit.

  According to the powder forming method and the powder forming apparatus according to the present invention, the upper punch and the lower punch are advanced by CNC position control, so that the positions and speeds of the upper punch and the lower punch can be accurately controlled. Moreover, it can be stopped accurately at a predetermined position of the die.

  A fourth aspect of the present invention is the powder molding apparatus according to the second or third aspect, wherein the second pressurizing control means includes a quartz crystal piezoelectric sensor. .

  According to the powder molding method and the powder molding apparatus according to the present invention, since the second pressurization control means includes the quartz piezoelectric sensor, accurate pressurization is possible in a wide pressurization range from a low pressurization region to a high pressurization region. Pressure control can be performed.

  According to the powder molding method and the powder molding apparatus according to the present invention, the density of the powder molded product can be made substantially constant regardless of the weight of the material powder filled in the filling portion. As a result, it is possible to reduce the variation between the products of the size of the sintered powder after sintering.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram showing a powder molding apparatus 1 according to this embodiment. The powder molding apparatus 1 is a die in which a lower punch connected to a lower ram is movable forward and backward with respect to a die while the die is fixed. This is a powder molding apparatus in the case of a fixed molding method.

  The powder molding apparatus 1 includes a die set (die) 10 and a powder molding press 50. The die set 10 includes a die 11 in which a filling portion A filled with a metal powder (material powder) P is formed; A lower punch 21 that is attached to the die 11 so as to be movable relative to the die 11 and defines the filling portion A together with the die 11, and an upper punch 31 that is disposed above the die 11 and supported so as to be able to advance and retreat relative to the die 11 is doing.

In addition, the powder molding apparatus 1 includes a first pressurization control unit that advances and pressurizes the upper punch 31 and the lower punch 21 to respective predetermined positions of the die 11, and the upper punch 31 and the lower punch 21 are in respective predetermined positions. The second pressurizing control means is formed to advance at least one of the upper punch 31 and the lower punch 21 until the punch reaches a predetermined pressurizing force.
The die 11 is disposed at the center of the die plate 12, and a guide hole 18 </ b> H is formed in the die plate 12.

The lower punch 21 is erected on the lower punch plate 13 that is movable relative to the base plate 14 fixed on the main body bed 68, and the lower punch plate 13 is lifted by a push-up plate 44 via a push-up rod 40. The push-up plate 44 is connected to the T-shaped joint 45, and the T-groove 45A of the T-shaped joint 45 is connected to the T-shaped portion of the lower ram 61 so that the lower ram 61 moves forward and backward. As a result, the lower punch 21 and the lower punch plate 13 are moved in the vertical direction together with the push-up plate 44.
The die plate 12 is fixed to the base plate 14 via a support member 41.

  Further, as shown in FIG. 2, the push-up plate 44 and the T-shaped joint 45 are connected to each other via a lower pressurizing force measurement sensor S1 and are connected to the lower pressurizing force measuring sensor S1 by a guide rod 46 other than in the axial direction. It is designed to suppress the application of force in the direction.

  The guide rod 46 is erected on the T-shaped joint 45 by the male screw portion 46C being screwed into the screw hole 45C, and a cylindrical guide portion 46B formed on the distal end side of the shaft portion is formed on the push-up plate 44. The guide hole 44D is slidably inserted. In FIG. 2, only one guide rod 46 is shown, but in this embodiment, two guide rods 46 are provided at positions symmetrical to the lower pressurizing force measuring sensor S1.

  As shown in FIG. 3, the lower pressurizing force measurement sensor S <b> 1 includes a screw member 42 and a crystal piezoelectric load washer (crystal piezoelectric sensor) 43, and the screw member 42 is the center of the T-shaped joint 45. A through-hole formed in the central portion of the push-up plate 44 through a hole formed in the center of the quartz piezoelectric load washer 43, with the male screw portion 42A screwed into the screw hole 45B formed in the portion. The push-up plate 44 and the T-shaped joint 45 are connected by causing the shaft portion 42C to pass through 44B and screwing the nut 42B into the male screw portion on the distal end side of the screw member 42 in the recess 44C. .

  The crystal piezoelectric load washer 43 includes a load washer main body 43A in which a plurality of crystal element disks each having a plate-like crystal formed in a ring shape are stacked, and an electrode portion 43B arranged so as to surround the load washer main body 43A. When the load washer main body 43A receives a force in the stacking direction, the charge generated in proportion to the force is collected by the electrode portion 43B and the charge can be taken out as a signal by a cable (not shown). It is like that.

  The crystal piezoelectric load washer 43 is attached in a so-called preload state in which a predetermined force is applied between the push-up plate 44 and the T-shaped joint 45 by the screw member 42 described above. The force acting in both the direction in which the T-type joint 45 approaches (pressing force) and the direction in which the push-up plate 44 and the T-type joint 45 separate (tensile force) can be measured.

  As this quartz piezoelectric load washer 43, for example, it is possible to obtain a measurement value based on a dynamic resolution of less than 0.01 N in a wide measurement range of several N to 400 kN, and is suitable for pressure control. It is.

The upper punch 31 is fixed to the upper punch plate 34 and is erected downward (in the direction of the die 11) on the upper punch plate 34 so that the upper punch 31 can be inserted into the filling portion A of the die 11.
The upper punch plate 34 is connected to the upper ram 71 via an upper connecting member 35 and a T joint 36 provided on the upper punch plate 34.

  When the guide rod 18 is erected on the upper punch plate 34 and is slidably inserted into the guide hole 18H formed in the die plate 12, the upper punch 31 moves up and down with respect to the die 11. Therefore, it is possible to suppress the deviation from the die 11.

  As shown in FIG. 4, the upper connecting member 35 and the T joint 36 are connected via the upper pressure measurement sensor S <b> 2 and are erected in a screw hole 36 </ b> C formed in the T type joint 36. A cylindrical guide portion 37B formed on the distal end side of 37 is slidably inserted into a guide hole 35D formed in the first upper connecting member 35A, so that the upper pressurizing force measuring sensor S2 has a direction other than the axial direction. It is designed to suppress the application of force in the direction. In FIG. 4, only one guide rod 37 is shown, but in this embodiment, two guide rods 37 are provided at positions symmetrical to the upper pressure measurement sensor S2.

  The upper pressure sensor S2 includes a screw member 38 and a quartz piezoelectric load washer 39. The screw member 38 has a male screw portion 38A in a screw hole 36B formed in the center portion of the T-shaped joint 36. The shaft portion of the screw member 38 is passed through a through hole formed in the center portion of the first upper connecting member 35A through a hole formed in the center of the quartz piezoelectric load washer 39. In addition, the upper connecting member 35A and the T-shaped joint 36 are connected to each other by screwing a nut 38B into the male screw portion on the distal end side of the screw member 38 in the recess 35C.

  Further, below the first upper connecting member 35A, a second upper connecting member 35B is attached by an attaching member (not shown). The configuration of the quartz piezoelectric load washer 39 is the same as that of the quartz piezoelectric load washer 43, and therefore the description thereof is omitted.

  As shown in FIG. 1, the powder molding press 50 includes a lower press main body 60, a press upper main body 70, and a control unit 80. The press lower main body 60 and the press upper main body 70 are: They are connected by a connecting member 52.

  The lower press body 60 includes a lower ram 61, a lower ram drive 62, a main body support 63, a lower ram drive support plate 64, a lower ram base plate 65, a detent rod 66, and a lower ram guide. The plate 67 and the main body bed 68 are provided. The main body support portion 63, the lower ram drive portion support plate 64, the lower ram base plate 65, the lower ram guide plate 67, and the main body bed 68 are arranged from below. Arranged in order, the detent rod 66 is erected between the lower ram base plate 65 and the lower ram guide plate 67.

  The lower ram drive unit 62 includes a lower ram drive motor 62M provided on the lower ram drive unit support plate 64, a drive pulley 62A provided on a rotating shaft of the lower ram drive motor 62M, a transmission belt 62B, and a driven pulley 62C. And a lower ram drive shaft 62D concentric with the driven pulley 62C, the transmission belt 62B is wound around the drive pulley 62A and the driven pulley 62C, and the rotation of the lower ram drive motor 62M is driven by the driven pulley 62C. The lower ram drive shaft 62D is transmitted and rotated.

  Further, a male screw 62E formed on the front end side of the lower ram drive shaft 62D is disposed so as to be screwed with a female screw 61A extending along the axis from the center of the lower end surface of the lower ram 61. By rotating 62D, the lower ram 61 is raised and lowered.

  The lower ram 61 is formed with a female screw 61A engageable with a male screw 62E on the lower side of the lower ram 61. The outer periphery of the lower ram 61 is inserted into a guide member 67A provided on the lower ram guide plate 67. The lower ram 61 is fixed to the lower ram base plate 65 and is erected on the lower ram base plate 65.

  The lower ram base plate 65 has a through hole 65A formed at the center thereof, the female screw 61A of the lower ram 61 is concentric with the through hole 65A, and the lower ram drive shaft 62D is inserted into the female screw 61A of the lower ram 61. The male screw 62E and the female screw 61A are engaged.

Further, when the non-rotating rod 66 passes through the hole 65B formed in the lower ram base plate 65, when the lower ram drive shaft 62D of the lower ram drive motor 62M rotates, the lower ram 61 and the lower ram base plate 65 are It is prevented from rotating.
As a result, when the lower ram drive shaft 62D of the lower ram drive motor 62M is rotated, the male screw 62E of the lower ram drive shaft 62D and the female screw 61A of the lower ram 61 are engaged to rotate the lower ram drive motor 62M. Is converted into vertical movement, so that the lower ram 61 moves forward and backward.

  The press upper body 70 includes an upper ram 71, an upper ram drive unit 73, a support plate 74, an upper ram base plate 75, a detent rod 76, and an upper ram guide plate 77. The upper ram base plate 75 and the upper ram guide plate 77 are arranged in this order from above, and the detent rod 76 is erected between the upper ram base plate 75 and the upper ram guide plate 77.

  The upper ram drive unit 73 includes an upper ram drive motor 73M attached to the support plate 74, a drive pulley 73A provided on the rotation shaft of the upper ram drive motor 73M, a transmission belt 73B, a driven pulley 73C, and a driven pulley. 73C and an upper ram drive shaft 73D concentric with each other. A transmission belt 73B is wound around the drive pulley 73A and the driven pulley 73C, and the rotation of the upper ram drive motor 73M is transmitted to the driven pulley 73C. The ram drive shaft 73D is rotated.

  In the upper ram 71, a female screw 71A that can engage with the male screw 73E is formed at the center of the upper end surface of the upper ram 71, and the outer periphery of the upper ram 71 is inserted into a guide member 77A provided on the upper ram guide plate 77. The upper ram 71 has a base end (upper side) fixed to the upper ram base plate 65 and is erected on the upper ram base plate 75.

  Further, the rotation stop rod 76 is passed through the hole 75B formed in the upper ram base plate 75, so that the upper ram 71 and the upper ram base plate 75 are prevented from rotating when the upper ram drive shaft 73D rotates. ing.

  Further, a male screw 73E formed on the front end side of the upper ram drive shaft 73D is arranged to be screwed with a female screw 71A formed along the axis from the center of the lower end surface of the upper ram 71. The upper ram 71 is raised and lowered by rotating 73D.

  The control unit 80 includes a pressurization control unit 81 and a CNC control unit 82. The pressurization control unit 81 includes the lower punch 21 and the upper pressurization sensor S2 based on signals input to the lower pressurization sensor S1 and the upper pressurization sensor S2. Each pressurizing force applied to the metal powder P by the upper punch 31 is calculated, and when the pressurizing force satisfies a predetermined numerical value, a signal is output to the CNC control unit 82.

  The CNC control unit 82 uses a preset program and signals from encoders (not shown) provided in the lower ram drive motor 62M and the upper ram drive motor 73M, respectively, to drive the lower ram drive motor 62M and the upper ram drive. A signal instructing rotation is output to each of the motors 73M to control the position, speed, stop operation, and the like of the lower ram 61 and the upper ram 71, and constitutes a first pressurizing control means. Yes.

  In addition, the CNC control unit 82, together with the lower pressurization sensor S1, the upper pressurization sensor S2, and the pressurization control unit 81, is programmed in advance after the lower punch 21 and the upper punch 31 reach their predetermined positions. In addition to the signal from the encoder, the lower ram driving motor 62M and the upper ram driving are performed by a signal that the pressing force of the lower pressing force sensor S1 and the upper pressing force sensor S2 from the pressing force control unit 81 reaches a predetermined value. Until the rotation of the motor 73M is stopped, at least one of the upper punch 31 and the lower punch 21 is advanced to constitute second pressure control means for forming metal powder.

Next, the case where the powder molded product W is manufactured by the powder molding apparatus 1 will be described with reference to FIGS.
5 and 6 show the operation of the die set 10. FIG. 5 shows a schematic operation of the lower punch 21 and the upper punch 31 with respect to the fixed die 11, and FIG. 6 shows time on the horizontal axis. 6 shows the relative positional relationship between the lower punch 21 and the upper punch 31. L21 in FIG. 6 is an operation diagram of the lower punch 21, L31 is an operation diagram of the upper punch 31, and L11 is an operation diagram. The position of the upper surface of the die 11 is shown.

  First, as shown in FIG. 5A, the upper punch 31 is stopped at a predetermined position above the die 11, and the lower punch 21 is disposed at a predetermined position on the filling portion A of the die 11, and a shoe box (not shown) is provided. The metal powder P is filled in the filling portion A by moving forward. (FIG. 6, first step D1)

  Next, the upper punch 31 is lowered toward the filling portion A by rotating the upper ram drive motor 73M. (Fig. 6, second step D2)

  Next, when the upper punch 31 reaches the upper surface of the die 11, as shown in FIG. 5B, the upper punch 31 is inserted into the filling portion A and the lower punch driving motor 62M is driven to The lower punch 21 is raised at the same speed as 31 to compact the metal powder P from above and below. (Fig. 6, third step D3)

  Next, when each of the upper punch 31 and the lower punch 21 has advanced to a predetermined position of the die 11, the upper punch 31 and the lower punch 21 are temporarily stopped, and then the upper punch 31 is moved as shown in FIG. When the pressure applied to the metal powder P by the lower punch 21 and the upper punch 31 measured by the lower pressurization sensor S1 and the upper pressurization sensor S2 reaches a predetermined value by further moving forward, FIG. As shown in FIG. 6, the rotation of the upper ram drive motor 73M is stopped and the lowering of the upper punch 31 is stopped (FIG. 6, fourth stroke D4). At this time, the upper and lower punches 31 and 21 may hold the metal powder P in a pressurized state for a short time.

  Thereafter, as shown in FIG. 5E, the lower ram drive motor 62M and the upper ram drive motor 73M are driven, and the lower ram 61 and the upper ram 71 rise synchronously, and the upper punch 31 and the lower punch 21 are powdered. It rises while holding the molded product W. (FIG. 6, 5th process D5)

  As shown in FIG. 5 (F), when the lower surface of the powder molded product W rises to the surface of the die 11 and the powder molded product W is extracted from the die 11, the lower punch 21 stops rising, and the upper ram is driven. The motor 73M rotates to raise the upper punch 31 to the original position together with the upper punch plate 34. When the upper punch 31 is raised, the holding of the powder molded product W is released. (Fig. 6, fifth step D6)

  Thereafter, when the powder molded product W is removed from the die 11 by a take-out device (not shown), the lower ram driving shaft 62D of the lower ram driving motor 62M rotates reversely as shown in FIG. At the same time, the lower punch 21 descends and returns to the origin position. (FIG. 6, seventh step D7)

According to the powder molding method and the powder molding apparatus 1 according to the above-described embodiment, the upper punch 31 and the lower punch 21 are relatively advanced to their respective predetermined positions on the die 11 so as to be compressed to near the final dimensions as the powder molded product W. After powdering, the upper punch 31 is advanced until it reaches a predetermined pressing force, so that it is possible to suppress variations in density among the products of the powder molded product W.
As a result, since the shrinkage when the powder molded product W is sintered to obtain a powder sintered product is made substantially constant, dimensional variations between products of the respective powder sintered products can be suppressed.
In addition, since the dimension in the direction orthogonal to the pressurizing direction is constant at the stage of the powder molded product, it is possible to particularly reduce the dimensional variation between products.

  Further, since the punch 31 and the lower punch 21 are advanced by CNC position control, the upper punch 31 and the lower punch 21 are advanced so as to be accurately stopped at a predetermined position close to the final dimension of the powder molded product W. The dimensional variation in the pressurizing direction of the molded product W can be suppressed.

In addition, since the second pressurization control means includes the quartz piezoelectric load washer 43, it is possible to perform accurate pressurization control in a wide pressurization range from a low pressurization region to a high pressurization region. Regardless of the filling weight of the metal powder P, the density of the powder molded product W can be made substantially constant.
Further, since the pressure is applied by the first pressurizing means and the pressurization by the second pressurizing means is performed immediately after that, the cycle time is hardly extended.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the above embodiment, The position control of the upper punch and the lower punch is performed using a screw structure provided on the lower ram drive shaft 62D and the lower ram 61, a screw structure provided on the upper ram drive shaft 73D and the upper ram 71, and a CNC position control device. However, the upper punch 31 and the lower punch 21 may be operated using a control device other than the CNC position control device or a drive device other than the screw structure. Further, instead of the encoder, other position measuring means such as a linear scale can be used.

  In the above-described embodiment, only the upper punch 31 moves forward with respect to the die 11 by the second pressurizing means, and both the lower pressure sensor S1 and the upper pressure sensor S2 reach a predetermined value. Although the case where the advance of the upper punch 31 is stopped has been described, the punch advanced by the second pressurizing means may be the lower punch 21 and / or the upper punch 31. It is freely selectable whether the advance of each punch by the pressurizing means 2 is the measured value of one of the lower pressurizing sensor S1 and the upper pressurizing sensor S2, or both measured values.

  In the above-described embodiment, the second pressurizing upper punch 31 or the lower punch 21 is advanced by using a quartz piezoelectric load washer with respect to the second pressurizing means that advances until the predetermined pressurizing force is reached. Although the case of measuring the pressure has been described, instead of the quartz piezoelectric load washer, for example, a solidly formed quartz piezoelectric sensor or a pressure measuring means other than the quartz piezoelectric sensor can be used.

  In the above embodiment, the case where each of the lower punch 21 and the upper punch 31 is single has been described. However, either one or both of the lower punch 21 and the upper punch 31 may be composed of a plurality of punches. Any one or both of the lower punch 21 and the upper punch 31 may be provided with a core rod.

  Moreover, in the said embodiment, although the case where the powder molded product W was shape | molded using the metal powder P as material powder was described, it replaced with the metal powder P, and cemented carbide alloy powder, ceramic powder, cermet powder, etc. It is also possible to use cutting inserts, cutting tools, and other various products for production.

  In the above embodiment, the case where the die 11 is fixed to the powder forming press 50 and the upper punch 31 and the lower punch 21 advance with respect to the die 11 has been described. Is fixed to the powder forming press 50, the die 11 is connected to the lower ram 61, and the die 11 is lowered by 1/2 with respect to the lowering amount of the upper punch 31. Is also possible.

It is a figure which shows the outline of the powder shaping | molding apparatus based on this invention. It is a figure which shows the attachment relationship of the lower side pressurization sensor which concerns on this invention. It is a figure explaining the applied pressure sensor which concerns on this invention. It is a figure which shows the attachment relationship of the lower side pressurization sensor which concerns on this invention. It is a figure which shows the typical operation | movement of the metal mold | die which concerns on this invention, (A) to (G) shows the positional relationship of the lower punch and the upper punch in each process. It is a figure which shows operation | movement of the metal mold | die which concerns on this invention, and shows the positional relationship of the die | dye, a lower punch, and an upper punch in each process according to elapsed time.

Explanation of symbols

A Filling part P Metal powder (material powder)
DESCRIPTION OF SYMBOLS 1 Powder molding apparatus 10 Die set 11 Die 21 Lower punch 31 Upper punch 39, 43 Quartz piezoelectric load washer 82 CNC control part

Claims (4)

A die formed with a filling portion filled with material powder;
A lower punch mounted relative to the die and defining a filling portion with the die;
A method for producing a powder molded article by a powder molding apparatus, comprising an upper punch disposed above the die and supported so as to be movable back and forth with respect to the die,
The upper punch and the lower punch are pressed closer to each predetermined position of the die and compacted,
After the upper punch and the lower punch reach the predetermined positions, at least one of the upper punch and the lower punch is moved forward until the pressing force of the punch reaches a predetermined value. A method for manufacturing a powder molded product. A die formed with a filling portion filled with material powder;
A lower punch mounted relative to the die and defining a filling portion with the die;
A powder molding apparatus provided with an upper punch disposed above the die and supported so as to be movable back and forth with respect to the die;
First pressurizing control means for advancing and pressurizing the upper punch and the lower punch to respective predetermined positions of the die;
Second pressurization control in which after the upper punch and the lower punch have reached their respective predetermined positions, at least one of the upper punch and the lower punch is advanced until the punch reaches a predetermined pressing force, and second pressure control is performed. And a powder forming apparatus. The powder molding apparatus according to claim 2,
The first pressure control means includes a CNC position control unit. The powder molding apparatus according to claim 2 or 3,
The powder pressing apparatus, wherein the second pressurizing control means includes a quartz crystal piezoelectric sensor.

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