JP2012245562A - Powder molding apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a powder molding apparatus capable of lessening the density variation between the powder molded bodies every filling portion when compacting the material powders using the apparatus having a plurality of filling portions.SOLUTION: The powder molding apparatus comprises: a die 11 on which two or more filling portions A for filling with the material powder P are formed; the lower punches 21 which are installed relatively movably to the die 11 and define the filling portions A together with the die 11; and the upper punches 31 which are disposed above the die 11 and are supported advanceably/retreatably with respect to the die 11, and molds the powder molded body by pressurizing the material powder P filled in the filling portion A. The apparatus includes a pressure detector for detecting a pressurizing force received by the filled material powder P every filling portion A.

Description

  The present invention relates to a powder molding apparatus for compacting a material powder to form a powder molded product.

As is well known, when a powder material such as metal or ceramic is used as a powder molded product, the die formed with a filling portion, the lower punch that defines the filling portion together with the die, and the filling portion can be moved forward and backward. It is common to use a powder molding apparatus equipped with an upper punch, and after the material powder is filled in the filling portion, the upper powder and the lower punch are used to compact the powder (see, for example, Patent Document 1).
By sintering the powder molded product at a high temperature, powder sintered products such as automobile parts and electronic parts are produced.

  For powder molded products, if the degree of shrinkage during sintering differs depending on the density, the size and weight after sintering will vary, so it is necessary to suppress the density variation during molding, and various technologies have been developed for this purpose. . For example, a technology is disclosed in which the upper punch and the lower punch are advanced to a predetermined position in the filling portion, and then the upper punch is advanced until reaching a predetermined pressure (for example, see Patent Document 2). ).

JP 2008-73726 A JP 2008-266752 A

  However, in general, since the upper punch and the lower punch are each driven by a common drive source (for example, one motor), when the powder molding apparatus has a plurality of filling parts, Depending on the amount of material powder filled, there is a problem in that a difference is easily caused in the pressing force in each filling portion. As a result, there is a variation in density between the powder molded products, and there is a problem in that the size of the powder sintered product varies.

  The present invention has been made in view of such circumstances, and in the case of molding a material powder using a powder molding apparatus having a plurality of filling portions, the density variation between the powder molded products for each filling portion is reduced. An object of the present invention is to provide a powder molding apparatus capable of performing the above.

In order to solve the above problems, the present invention proposes the following means.
According to the first aspect of the present invention, a die in which a plurality of filling portions filled with material powder is formed, and the die are attached so as to be relatively movable with respect to the die, and define the plurality of filling portions together with the die A plurality of lower punches, and a plurality of upper punches disposed above the die and corresponding to the plurality of filling parts and capable of advancing and retreating with respect to the die. A powder molding apparatus for molding a powder molded product by pressurizing the material powder, comprising pressure detecting means for detecting the pressure applied to the filled material powder for each filling section. .

  According to the powder molding apparatus according to the present invention, when a powder molded product is molded by a powder molding apparatus having a plurality of filling parts, it is possible to detect the pressing force at the time of compaction in each filling part from the pressure detection means. Therefore, it is possible to grasp the density of the powder molded product molded at each filling portion. As a result, it is possible to suppress the occurrence of density variation between powder molded products.

  A second aspect of the present invention is the powder molding apparatus according to the first aspect, wherein the plurality of sets of upper and lower punches corresponding to the respective filling portions each include at least one of the lower punch and the upper punch. It is connected to the interval adjusting mechanism, and is configured to adjust the vertical punch interval of each set based on the detection result of the pressure detecting means.

  According to the powder molding apparatus according to the present invention, each set of the upper and lower punches has at least one of the lower punch and the upper punch connected to the punch interval adjustment mechanism, and based on the detection result of the pressure detection means, Since the interval between the upper and lower punches of the set is adjusted, the difference in the applied pressure in each filling portion can be reduced, and consequently the density variation between the powder molded products can be reduced.

  A third aspect of the present invention is the powder molding apparatus according to the second aspect, wherein the pressure in each of the filling portions is determined based on a plurality of times of pressure in each of the filling portions detected by the pressure detecting means. The punch interval adjusting mechanism is adjusted so as to be within a predetermined range.

  According to the powder molding apparatus according to the present invention, the punch interval adjusting mechanism is configured so that the pressurizing force in each filling portion is within a predetermined range based on the multiple pressurizing forces in each filling portion detected by the pressure detecting means. Since the adjustment is performed, it is possible to reduce the variation in density between the powder molded products in consideration of the tendency of the material powder supply and the like.

  Invention of Claim 4 is the powder shaping | molding apparatus of any one of Claims 1-3, Comprising: The said pressure detection means detected among the powder molded products shape | molded in these filling parts. It is characterized by comprising an excluding means for excluding those whose applied pressure is outside the set applied pressure range.

  According to the powder molding apparatus according to the present invention, since the applied pressure detected by the pressure detection means is out of the set pressure range among the powder molded products molded in the plurality of filling portions, the exclusion means excludes the applied pressure. Powder molded products whose pressure is outside the predetermined range can be surely excluded, and as a result, density variation between the powder molded products can be reduced.

  According to the powder molding apparatus according to the present invention, it is possible to reduce the density variation between the powder molded products by grasping the pressing force at the time of compaction in each filling portion.

1 is a schematic configuration diagram of a powder molding apparatus according to a first embodiment of the present invention. It is a figure explaining the principal part structure of the powder molding apparatus which concerns on 1st Embodiment. It is a figure explaining the effect | action of the powder molding apparatus which concerns on 1st Embodiment. It is a figure explaining the principal part structure of the powder molding apparatus which concerns on the 2nd Embodiment of this invention.

Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
For example, as shown in FIG. 1, the powder molding apparatus 1 according to the first embodiment is a die-fixed molding 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. It is a type of powder forming apparatus.

  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 which 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; An elevating mechanism (punch interval adjusting mechanism) 80 for elevating and lowering 21 is provided.

  Here, the lower punch 21 and the upper punch 31 are configured to be movable in the vertical direction on the axis O of the corresponding filling portion A among the filling portions A formed in the die 11. For example, the case where there are two filling sections A and upper and lower punches 31 and 21 is shown. The die 11 is disposed at the center of the die plate 12, and a hole 18H 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 to the main body bed 68. The lower punch plate 13 is connected to the push-up plate 44 via the push-up rod 40. The push-up plate 44 is connected to the T-shaped joint 45 while being connected.

  Further, the T groove 45A of the T-shaped joint 45 is connected to the T-shaped portion of the lower ram 61, and the lower punch 21 and the lower punch plate 13 are moved up and down together with the push-up plate 44 as the lower ram 61 advances and retreats in the vertical direction. It is designed to move in the direction. The die plate 12 is fixed to the base plate 14 via a support member 41. Further, the push-up plate 44 and the T-shaped joint 45 are connected to each other by a connecting rod 46.

For example, as shown in FIG. 2, the elevating mechanism 80 includes two jacks 80 </ b> J provided on the lower punch plate 13 and corresponding to the lower punches 21.
The jack 80 </ b> J engages with the worm wheel 83 by a spline or the like and rotates together with the worm wheel 83, the worm gear 82 formed on the output shaft of the lift motor 81, the worm wheel 83 engaged with the worm gear 82, and the like. The lower punch support shaft 84 and a male screw formed on the outer periphery of the push-up rod 40 and engaged with a female screw (not shown) on the inner periphery of the lower punch support shaft 84 are provided.

  Further, the lower punch 21, the push-up rod 40, the worm wheel 83, and the lower punch support shaft 84 are arranged coaxially, and the lower punch support shaft 84 is movable in the vertical direction with respect to the worm wheel 83 and the push-up rod 40. The worm gear 82 and the worm wheel 83 are covered with a housing 85.

With this configuration, the elevating mechanism 80 is configured such that the elevating motor 81 rotates in each jack 80J, whereby the worm wheel 83 and the lower punch support shaft 84 are rotated via the worm gear 82, and the lower punch support shaft 84 is connected to the push-up rod 40. Relative rotation.
When the lower punch support shaft 84 rotates relative to the push-up rod 40, the female screw of the lower punch support shaft 84 and the male screw of the push-up rod 40 are engaged, and the lower punch support shaft 84 and the push-up rod 40 of the lower punch 21 are engaged. The position in the axial direction with respect to is changed.

As a result, the lower punch 21 disposed on the upper surface of the lower punch support shaft 84 moves in the direction of the axis O, the distance between the upper and lower punches 31 and 21 is adjusted, and the pressure applied to the metal powder P in the filling portion A is adjusted. be able to.
The load applied to the lower punch 21 during compaction and the discharge of the powder molded product is transmitted by the female screw on the inner periphery of the lower punch support shaft 84 and the male screw on the outer periphery of the push-up rod 40.
Thus, each jack 80J can adjust the space | interval of each upper-and-lower punch 31, 21 individually, and can make the applied pressure in each filling part A small.

  The plurality of upper punches 31 are respectively installed on the upper punch plate 34 via support members 34 </ b> A, and are erected on the upper punch plate 34 downward (in the direction of the die 11). It can be inserted. 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.

  A guide rod 18 is erected on the upper punch plate 34, and the guide rod 18 is slidably inserted into a guide hole 18 </ b> H formed in the die plate 12, so that the upper punch 31 moves up and down with respect to the die 11. When moving in the direction, the shift from the die 11 is suppressed. The upper connecting member 35 and the T joint 36 are connected to each other via a connecting rod 37.

  Further, a load cell 90 (pressure detecting element) serving as a pressure detecting means is provided between the upper punch 31 and the upper punch plate 34, and the load cell 90 is made of metal powder filled in the filling portion A with the upper punch 31. The pressure applied when pressing and compacting is detected and input to the control unit C.

  As shown in FIG. 1, the powder molding press 50 includes a press lower body portion 60, a press upper body portion 70, and a control unit C. The press lower body portion 60 and the press upper body portion 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, and the outer periphery of the lower ram 61 is inserted into a guide member 67A provided on the lower ram guide plate 67 and slides in the vertical direction. The lower ram 61 has a base end portion (lower side) 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 C controls the push-up rod 40, the lower ram 61, the upper ram 71, and the lifting mechanism 80 on the basis of a preset procedure, drives the upper and lower punches 31 and 21, and compacts the metal powder p. Then, the powder molded product W is molded and discharged to the outside of the die 11, and the vertical position of the lower punch 21 is adjusted based on the applied pressure in each filling portion A detected by the load cell 90, so that each filling portion The pressure applied at A is adjusted.

  Next, the operation of the powder molding apparatus 1 will be described with reference to FIG. FIG. 3 schematically shows one set of operations of the two sets of upper and lower punches 31 and 21 that perform the same operation.

  First, as shown in FIG. 3A, 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 die 11 that defines the filling portion A, not shown. The shoe box is moved to fill the filling portion A with the metal powder P.

  Next, as shown in FIG. 3B, the upper ram drive motor 73M is rotated to lower the upper punch 31 toward the filling portion A, and the lower punch drive motor 62M is driven to move the lower punch 21 upward. The metal powder P is pressed from above and below by raising the punch 31 at the same speed.

  Next, as shown in FIG. 3C, the upper punch 31 is further advanced to compact the metal powder P. The load cell 90 detects the pressure applied by the upper punch 31 in (B) and (C). The pressurizing force of each filling part A detected by the load cell 90 is input to the control part C, and for example, an adjustment amount (amount of movement in the vertical direction) of the lower punch 21 is calculated with reference to a data table or the like. Based on this, the lifting motor 81 is driven, and the vertical position of the lower punch 21 is adjusted.

  Next, as shown in FIG. 3D, when the upper punch 31 reaches the lowering end, the upper ram drive motor 73M is stopped to stop the lowering of the upper punch 31. 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. 3E, the lower ram driving motor is driven so that the lower ram 61 and the upper ram 71 are driven synchronously and the upper punch 31 and the lower punch 21 are lifted while holding the powder molded product W. 62M and the upper ram drive motor 73M are driven.

  Next, as shown in FIG. 3 (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. When the raising of the lower punch 21 stops, the holding of the powder molded product W is released, and then the upper ram drive motor 73M is driven until the upper punch 31 is raised to the original position.

  Next, 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. The lower punch 21 moves downward and returns to the initial position.

  According to the powder molding apparatus 1, when the metal powder P is molded into a powder molded product W by a plurality of filling parts A, the pressure applied to each filling part A is detected from the load cell 90. It is possible to reduce the variation in the applied pressure of the powder P and to suppress the occurrence of the density variation between the powder molded products W.

  Further, according to the powder molding apparatus 1, the lower punch 21 corresponding to each filling portion A is connected to the lifting mechanism 80, and the interval between the upper and lower punches of each set is adjusted based on the detection result of the load cell 90. It is possible to reduce the difference in the applied pressure in the portion A and to reduce the density variation between the powder molded products W.

  Further, according to the powder molding apparatus 1, the elevating mechanism 80 is adjusted so that the pressurizing force in each filling portion A is within a predetermined range based on the multiple pressurizing forces in each filling portion A detected by the load cell 90. The variation in density between the powder molded products W can be reduced in consideration of the tendency of supplying the metal powder P and the like.

  Further, according to the powder molding apparatus 1, by adjusting the distance between the upper and lower punches 31 and 21 by the lifting mechanism 80, the variation in the applied pressure in each filling portion A is reduced, and consequently the density between the powder molded products W. The variation of can be reduced.

  Further, according to the powder molding apparatus 1, since the load cell 90 is disposed between the upper punch 31 and the upper punch plate 34, the load cell 90 can accurately detect the pressure applied to the upper punch 31. it can.

Next, a second embodiment of the present invention will be described with reference to FIG.
The second embodiment is different from the first embodiment in that the load cell 90 is provided not in the die set 10 but in the upper punch plate 34 of the powder forming press 50. Since others are the same as those of the first embodiment, the same reference numerals are given and description thereof is omitted. According to the second embodiment, since the load cell 90 is provided in the powder molding press 50, it is not necessary to provide the load cell 90 for each die set 10, and the capital investment cost can be reduced.

In addition, this invention is not limited to the said embodiment, A various change can be added in the range which does not deviate from the meaning of this invention.
For example, in the above-described embodiment, the case where the load cell 90 is provided for each upper punch 31 has been described. However, the lower punch 21 may be provided with pressure detection means, or both the lower punch 21 and the upper punch 31 may detect pressure. Means may be provided.

  Moreover, although the said embodiment demonstrated the case where a pressurizing force was adjusted by moving the lower punch 21 up and down by the raising / lowering mechanism (punch space | interval adjustment mechanism) 80 based on the applied pressure which the load cell 90 detected, the raising / lowering mechanism Instead of adjusting the vertical position of the lower punch 21 by 80, the vertical position of the upper punch 31 may be adjusted, or the pressing force may be adjusted by adjusting the vertical position of both the lower punch 21 and the upper punch 31. Good.

Further, instead of the lifting mechanism 80, a hydraulic jack controlled by a servo valve or the like may be used.
Further, instead of adjusting the distance between the upper and lower punches 31 and 21, the pressing force of each filling part A may be adjusted by adjusting the supply amount of the metal powder P to each filling part A.

  In addition, when there is an excluding means for excluding a specific powder molded product W out of the line, and there is a powder molding product W whose applied pressure detected by the pressure detecting means is outside a predetermined range, You may comprise so that the dispersion | variation in the density of the powder molded product W may be made small by removing the powder molded product W out of the powder molding apparatus 1 or a line.

  Moreover, although the said embodiment demonstrated the case where the powder shaping | molding apparatus 1 was a die fixed type, you may apply to the powder shaping | molding apparatus of other operation systems, such as a withdrawal system.

  According to the powder molding apparatus according to the present invention, when the material powder filled in the plurality of filling portions is compacted by the upper and lower punches operated by a common drive source, the density variation between the powder molded products is reduced. It can be used industrially.

P metal powder (material powder)
A Filling part W Powder molded product O Axis 1 Powder molding device 10 Die set 11 Die 13 Lower punch plate 21 Lower punch 31 Upper punch 34 Upper punch plate 50 Powder molding press 62 Lower ram drive motor 62M Lower ram drive motor 73 Upper ram drive 73M Upper ram drive motor 80 Lifting mechanism (punch interval adjustment mechanism)
90 Load cell (pressure detection means)

Claims (4)

A die formed with a plurality of filling portions filled with material powder;
A plurality of lower punches attached to the die so as to be movable relative to the die and defining the plurality of filling portions together with the die;
A plurality of upper punches disposed above the die and corresponding to the plurality of filling portions and capable of advancing and retreating with respect to the die,
A powder molding apparatus for molding a powder molded product by pressurizing the material powder filled in the filling portion,
A powder molding apparatus comprising pressure detecting means for detecting, for each of the filling portions, a pressure applied to the filled material powder. The powder molding apparatus according to claim 1,
Multiple sets of upper and lower punches corresponding to each filling part
Each of at least one of the lower punch and the upper punch is connected to a punch interval adjustment mechanism, and is configured to adjust the upper and lower punch intervals of each set based on the detection result of the pressure detection means. A powder forming apparatus. The powder molding apparatus according to claim 2,
A powder characterized in that the punch interval adjusting mechanism is adjusted based on a plurality of times of pressurizing force in each filling portion detected by the pressure detecting means so that the pressurizing force in each filling portion is within a predetermined range. Molding equipment. The powder molding apparatus according to any one of claims 1 to 3,
An apparatus for extruding powder, comprising: an excluding means for excluding those in which the applied pressure detected by the pressure detecting means is out of a set applied pressure range among the powder molded products formed in the plurality of filling sections.

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