JP2004298894A - Powder compact, its manufacturing method and molding die - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the number of working processes after die molding, to shorten manufacturing time, to improve the yield of products and to realize stable manufacturing process by manufacturing a powder compact having approximately L-shaped communicative hole only by die molding. <P>SOLUTION: By using a molding die provided with a die 10, a lower punch 20 and an upper punch 20 which are fit into the die 10, a horizontal pin 13 which is freely projected in a cavity 40 in the inside of the die by moving in the horizontal direction from the state where the pin is housed in the die and a vertical pin 22 which is freely projected 40 in the cavity 40 in the vertical direction, after filling a powder material into the cavity 40 of this forming die, the powder compacted body having the horizontal blind hole and a vertical blind hole communicating to the horizontal blind hole in the bottom part of the horizontal blind hole are obtained by compression-molding the powder material while connectig the horizontal pin 13 to the vertical pin 22. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an unmolded powder having a substantially L-shaped communication hole, a method for producing the same, and a molding die, which can be suitably used for molding of electronic components, specifically, dielectric filters, duplexers, and the like. Things.
[0002]
[Prior art]
Conventionally, when a powder compact is manufactured by pressure molding of a powder material, a die having a die hole in a vertical direction, and an upper punch and a lower punch inserted into the die hole of the die from above and below, respectively, are used. After filling the cavity formed in the die hole with the powder material, the powder material is pressurized and compressed between an upper punch and a lower punch to obtain a powder compact in the cavity. Are known.
[0003]
Further, when the powder unformed body to be pressure-formed has a horizontal hole, the horizontal pin for forming the horizontal hole is previously penetrated into the die hole so as to be able to be removed from the side thereof, After filling the cavity with the powder material, and then pressurizing and compressing the powder material in the cavity between the upper and lower punches, the neutral zone of the molded body is controlled to remove the molded body so as not to burden the horizontal pin. There is known a method of obtaining a powder green body having a horizontal hole by removing a horizontal pin before delivery. Here, the neutral zone is a zone where the pressure transmitted from the opposing punches is balanced inside the powder compact, and is a layer having the lowest value in the density distribution.
[0004]
Further, the following patent document describes a method for producing a powder compact having a stepped through-hole.
[0005]
[Patent Document 1] Japanese Patent Application Laid-Open No. 2001-355004
As described above, a powder compact in which a one-way through hole is formed by pressure molding of a powder material, and a powder compact in which a one-way blind hole (non-through hole) is formed are also known in the academic department. A substantially L-shaped communication hole is formed in the unformed powder body only by the mold forming process, with the horizontal blind hole and the vertical blind hole communicating with the horizontal blind hole at the bottom of the horizontal blind hole. The construction method has not been realized.
[0007]
Conventionally, when such a substantially L-shaped communication hole (a hole in which vertical and horizontal blind holes cross each other inside a molded body) is formed in a powder unmolded body, one hole is usually formed in a molding step. In general, it is common to form orthogonal L-shaped communication holes by drilling orthogonal holes in post-processing to form communication holes. However, when the powder molded product is small or the strength of the molded product is not sufficient, it is very difficult. This makes the processing difficult and increases the cost.
[0008]
In order to obtain a powder compact having a substantially L-shaped communication hole from the stage of the molding process, a mold structure in which a vertical (upward or downward) pin and a horizontal pin are brought into contact with each other is considered. When contacting the pin, even if the fine powder material adheres to the contact surface of the vertical pin and the horizontal pin, the amount of adhesion increases with each molding cycle, resulting in burrs of the molded body and the formation of communication holes is uncertain Becomes a defect.
[0009]
[Problems to be solved by the invention]
The present invention has been made in view of the above points, and by forming a powder molded body having a substantially L-shaped communication hole only by mold molding, reduction in processing after mold molding, It is an object of the present invention to provide a powder compact capable of shortening a manufacturing time by mold molding and improving a product yield.
[0010]
Further, the present invention enables a powder molded body having a substantially L-shaped communication hole to be produced only by die molding, thereby reducing the processing required after die molding, shortening the manufacturing time, and improving the product yield. Another object of the present invention is to provide a method for producing a powdery non-molded body and a molding die capable of improving the quality and realizing a stable production process, and as a result, economically advantageously producing a powdered molded body.
[0011]
Other objects and novel features of the present invention will be clarified in embodiments described later.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, the unmolded powder according to the invention of claim 1 of the present application has a horizontal blind hole, and a vertical blind hole communicating with the horizontal blind hole at the bottom of the horizontal blind hole. And formed only by a mold forming step.
[0013]
The molding die according to the invention of claim 2 of the present application has a configuration including a die, a lower punch and an upper punch fitted into the die,
A lateral pin that moves laterally from a state stored in the die and can protrude into a cavity inside the die,
A first vertical pin having a fitting hole through which the horizontal pin can penetrate in a vertically protruding state in the cavity.
[0014]
A molding die according to a third aspect of the present invention is characterized in that, in the second aspect, the cavity has a second vertical pin which is vertically protrudable in the cavity at a position coaxial with the first vertical pin.
[0015]
The method for manufacturing a powder compact according to the invention of claim 4 of the present application includes a die, a lower punch and an upper punch fitted into the die, and laterally moving from a state stored in the die to move the inside of the die. A molding die having a horizontal pin that can freely protrude into the cavity and a first vertical pin that can freely protrude in the cavity in the vertical direction is used.
After the powder material is put into the cavity of the molding die, the powder material is compression-molded in a state where the horizontal pins and the first vertical pins are connected.
[0016]
In the method of manufacturing a powder compact according to the invention of claim 5 of the present application, in claim 4, the first vertical pin has a fitting hole through which the horizontal pin can pass, and the horizontal pin is fitted with the horizontal pin. The first vertical pin and the horizontal pin are connected to each other by being fitted into a hole.
[0017]
In the method for manufacturing a powder compact according to the invention of claim 6 of the present application, the method according to claim 4 or 5, wherein the horizontal pin moves to a position immediately before a position where the horizontal pin is connected to the first vertical pin before being connected to the first vertical pin. Features.
[0018]
In the method for manufacturing a powder compact according to the invention of claim 7 of the present application, in claim 6, the molding die is provided with a second vertical pin that can protrude coaxially with the first vertical pin, and After the pin has moved to a position just before the position where the pin is connected to the first vertical pin, the first vertical pin moves to a height position where it can be connected to the horizontal pin, and the second vertical pin moves to the first vertical pin. It is characterized in that it moves in the same direction in synchronization with the pin.
[0019]
The method for producing a powder compact according to the invention of claim 8 of the present application is the method according to claim 7, wherein the powder material is transferred and filled between the first vertical pin and the second vertical pin before compression molding. It is characterized by making the density uniform.
[0020]
The method of manufacturing a powder compact according to the invention of claim 9 of the present application is the compression molding method according to claim 4, 5, 6, 7 or 8, such that the center of the lateral pin is located in the neutral zone of the compact of powder material. It is characterized by performing.
[0021]
The method for producing a powder compact according to the invention of claim 10 of the present application is the method according to claim 4, 5, 6, 7, 8, or 9, wherein after the compression molding, the compact is appropriately molded by the die, the lower punch, and the upper punch. The horizontal pin is pulled out in a state where the elastic deformation of the molding die is removed by holding at the pressure described above.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a powder non-molded product, a method for producing the same, and a molding die according to the present invention will be described with reference to the drawings.
[0023]
1 to 3 show an embodiment of a powder unmolded body, a method for producing the same, and a molding die according to the present invention.
[0024]
First, the structure of a molding die used in the present embodiment will be described. The molding die includes a die 10 having a die hole 11 penetrating in the vertical direction, a lower punch 20 slidable in the vertical direction along the inner surface of the die hole 11 (fitted into the die hole 11 so as to be able to move up and down), and And a punch 30.
[0025]
The die 10 has a horizontal pin hole 12 formed on one side of the inner surface. A horizontal pin 13 is provided in the horizontal pin hole 12 so as to be slidable in the horizontal direction. The horizontal pin 13 can move laterally from the stored state in which the front end surface matches the inner surface of the die hole 11 and protrude inside the die hole.
[0026]
A vertical pin hole 21 is formed in the lower punch 20, and a lower vertical pin (first vertical pin) 22 orthogonal to the horizontal pin 13 is slidable in the vertical pin hole 21 in the vertical direction. The lower punch 20 is movable from a storage state in which the lower punch 20 matches (or lowers) to a state in which the lower punch 20 projects from the upper surface. The lower vertical pin 22 has a fitting hole 23 through which the horizontal pin 13 can pass. For example, the horizontal pin 13 is a round bar having a circular cross section, the lower vertical pin 22 is a square bar having a rectangular cross section, and the lower vertical pin 22 is a member having a horizontal width larger than the diameter of the horizontal pin 13. However, in principle, the cross-sectional shapes of the horizontal pin 13 and the lower vertical pin 22 do not matter.
[0027]
A vertical pin hole 31 is formed in the upper punch 30, and an upper vertical pin (second vertical pin) 32 is provided in the vertical pin hole 31 so as to be slidable up and down (up and down). The upper punch 30 can be moved from a storage state in which the lower surface of the upper punch 30 matches (or rises above the lower surface) to a state in which the upper punch 30 projects from the lower surface. The upper vertical pin 32 has the same cross-sectional shape as the lower vertical pin 22.
[0028]
A set of the horizontal pins 13 and the vertical pins 22 and 32 may be provided in the same mold for the purpose of forming a plurality of substantially L-shaped holes in the powder compact.
[0029]
The press forming machine according to the present embodiment is a CNC (Computerized Numerical Control) press forming machine, and includes a die 10, a lower punch 20, an upper punch 30, and a lower vertical shown in FIGS. The position of the pin 22, the upper vertical pin 32, and the horizontal pin 13 can be controlled independently of each other.
[0030]
In the present embodiment, a case of the withdrawal method (a method in which the lower punch 20 is fixed, the upper punch 30 and the die 10 are lowered, and the lower punch is pressed by a relative speed difference) is illustrated.
[0031]
Next, a manufacturing process of a powder compact using the above-described molding die will be described with reference to FIGS. 1 to 3. In the drawings, black arrows indicate movement of each member, and white arrows indicate a pressing direction.
[0032]
First, referring to FIG. 1A, a first step showing a filling operation of a powder material will be described. In the first step, the lower punch 20 is fitted into the die hole 11 of the die 10 from below to form a cup-shaped cavity 40 having an upper opening, and the tip surface of the horizontal pin 13 is formed in the inner surface of the die hole 11. And the horizontal pin 13 is retracted, the lower vertical pin 22 is projected from the upper surface of the lower punch 20, and the fitting hole 23 is positioned higher than the horizontal pin 13. Then, the powder material 1a in the material supply container 50 that slides on the upper surface of the die 10 is filled into the cavity 40 as the powder material 1b to be molded. Here, at the time of filling the powder material, the fitting hole 23 of the lower vertical pin 22 is set at a position higher than the horizontal pin 13 because of the corner portion when the substantially L-shaped communication hole is formed in the powder compact. This is to make the compact density uniform. The reason why the horizontal pins 13 are stored in the die 10 and filled with the powder material is to prevent the uniform filling of the powder material from being hindered.
[0033]
In the second step showing the underfill operation of FIG. 1B, the powder material 1b is filled in the cavity 40 in the first step, and after the cutting process, the position of the horizontal pin 13 is filled in the cavity 40. The die 10 is raised so as to be located at the center in the height direction of the powder material 1b. This position is a position that becomes a neutral zone at the time of subsequent pressurization.
[0034]
In the third step of the horizontal pin insertion operation shown in FIG. 1C, after the underfill of the second step, a position close to the lower vertical pin 22 protruding upward in the cavity 40 (coupling (contact). The horizontal pin 13 is slid and protruded from the horizontal pin hole 12 until the position just before).
[0035]
In the fourth step showing the upper punch transfer start operation shown in FIG. 2A, after the third step, the upper punch 30 is filled in the cavity 40 so as to face the lower punch 20 with the powder material 1b interposed therebetween. Down to the surface of the powdered material. At this time, the front end surface of the upper vertical pin 32 is aligned with the lower end surface of the upper punch 30.
[0036]
In the fifth step of the powder transfer / filling operation in the cavity shown in FIG. 2B, the lower vertical pin 22 is moved from the position shown in FIG. 2A to a position where the horizontal pin 13 shown in FIG. At this time, in order to keep the powder material density on the lower vertical pin 22 constant, the upper vertical pin 32 is lowered completely in synchronization with the lower vertical pin 22, and the lower vertical pin 22 and The powder material is moved while the interval between the upper vertical pins 32 is kept constant (the amount of the powder material is kept constant). This is called transfer filling, and distortion is prevented by making the filling ratio and compression ratio of the area sandwiched between the vertical pins 22 and 32 the same as those of the surrounding area. In addition, if the lower vertical pin 22 and the upper vertical pin 32 are pre-compressed before the transfer, the density can be made uniform.
[0037]
In the sixth step showing the horizontal pin connecting operation of FIG. 2C, after the fifth step, the horizontal pin 13 is slidably projected in the horizontal direction, so that the upper part of the lower vertical pin 22 is fitted. The tip of the horizontal pin 13 is fitted and connected to the hole 23 (through hole). The gap between the fitting hole 23 and the fitting portion of the horizontal pin 13 is set to 20 μm to 50 μm as a gap used for fitting a general mold.
[0038]
In a seventh step showing the simultaneous vertical compression operation of FIG. 3A, in a state where the position of the lower punch 20 is held in the sixth step, pressure is applied to each of the die 10 and the upper punch 30 by a CNC press molding machine. At the same time, in the state of the powder compact 1 in which the powder material in the cavity 40 has been compression-molded, the die 10 is positioned so that the center of the horizontal pin 13 is located in the neutral zone of the powder compact 1. The positions of the pin 22, the upper punch 30, and the upper vertical pin 32 are controlled. At this time, the speed of each of the punches 20 and 30 is controlled, and the position and speed of the combined molding dies are controlled accurately so that the density of the molded body is as uniform as possible even during molding. The upper vertical pin 32 is stored such that the front end surface thereof coincides with the lower surface of the upper punch 30 before the completion of the compression molding.
[0039]
In an eighth step showing the depressurizing operation and the horizontal pin releasing operation in FIG. 3B, the die 10, the lower punch 20 and the upper punch 30 are applied to the die 10, after the simultaneous vertical compression operation of the seventh step is completed. The horizontal pin 11 that has been fitted into the fitting hole 23 of the lower vertical pin 22 is removed from the powder compact 1 while releasing the formed molding pressure (holding the powder compact 1 at a moderately low pressure). And stored in the lateral pin holes 12 of the die 10. Here, the molding pressure applied during the compression molding is released to perform punch control for removing the elastic deformation of the molding die, that is, the die 10 and each of the punches 20 and 30 (the die by the spring-back action of the molded body). Then, the horizontal pin 13 is removed from the powder compact 1. At this time, it is important for the upper punch 30 to hold the powder compact 1 at an appropriate pressure, and cracks, which are defects of the powder compact, often occur at this timing. The holding force differs depending on the strength and size of the powder compact.
[0040]
In the ninth step showing the extraction (first half) operation of FIG. 3C, after the end of the eighth step, the positions of the lower punch 20, the lower vertical pin 22, the upper punch 30, and the upper vertical pin 32 are held. In this state, the die 10 is moved downward so that the upper surface of the die 10 is the same as or lower than the upper surface of the lower punch 20, and the unformed powder body 1 formed in the cavity is extracted. Since this removal operation is performed in a state where the lower vertical pin 22 enters the powder compact 1, it is effective in preventing cracking of the powder compact 1.
[0041]
In the tenth step showing the extraction (second half) operation of FIG. 3D, after the ninth step is completed, the upper punch 30 is raised, and then the lower vertical pin 22 is removed from the powder compact 1 and the lower punch is removed. 20 are stored in the vertical pin holes 21. As a result, a powder molded body having a substantially L-shaped communication hole including the horizontal blind hole 2 and the vertical blind hole 3 communicating with the horizontal blind hole 2 at the bottom of the horizontal blind hole 2. 1 can be taken out.
[0042]
According to this embodiment, the following effects can be obtained.
[0043]
(1) A powder compact having a substantially L-shaped communicating hole including a lateral blind hole 2 and a vertical blind hole 3 communicating with the lateral blind hole 2 at the bottom of the lateral blind hole 2. No. 1 can be formed by a manufacturing method including only a mold forming step, and has advantages such as no processing and a reduction in manufacturing time. As a result, it is economically advantageous as compared with a processed product. Further, since the post-processing step can be omitted, the product yield is improved, and a homogeneous powder compact can be realized.
[0044]
(2) After the powder material 1b is put into the cavity 40 of the molding die, the horizontal pin 13 and the lower vertical pin 22 are joined (the horizontal pin 13 is fitted into the fitting hole 23 of the lower vertical pin 22). ), The powder material is compression-molded, so that a substantially L-shaped communication hole free of burrs can be formed in the powder molded body 1 even when the number of times of molding is increased. In particular, by fitting the horizontal pins 13 into the fitting holes 23 of the lower vertical pins 22, it is possible to reliably prevent minute powder from adhering to the contact surface between the lower vertical pins 22 and the horizontal pins 13. it can.
[0045]
(3) By filling the powder material into the cavity 40 when the horizontal pin 13 is stored, the filling operation of the powder material can be performed smoothly without being hindered by the horizontal pin 13. In addition, by setting the center of the lateral pin 13 in the neutral zone of the powder material before the compression molding and performing compression molding so as to be located in the neutral zone of the compact, the stress applied to the lateral pin 13 can be minimized. Then, the horizontal pin 13 can be removed from the powder compact 1.
[0046]
(4) When filling the cavity 40 of the molding die with the powder material, the fitting hole 23 of the lower vertical pin 22 is set at a position higher than the horizontal pin 13 and is lowered after the filling of the powder material to join the horizontal pin 13. Thereby, the density of the compact at the corners when the substantially L-shaped communication hole is formed in the powder compact can be made uniform.
[0047]
In the above-described embodiment, the withdrawal method (a method in which the lower punch is fixed and the upper punch and the die are lowered to perform the two-push molding, and the lower punch is also pressed by the relative speed difference) is shown. Also, the manufacturing method of the present invention can be applied.
[0048]
Further, in the above embodiment, the mold structure is such that the horizontal pin is fitted to the lower vertical pin. However, a fitting hole is formed in the upper vertical pin, and the horizontal pin is fitted to the upper vertical pin. A manufacturing method using a mold structure to be formed may be used.
[0049]
Further, in the present invention, it is obvious that any one of a circular column, an elliptic column, a prism, a polygonal column or the like, or a combination thereof can be used for the horizontal blind hole and the vertical blind hole.
[0050]
It will be obvious to those skilled in the art that the present invention is not limited to these, and various modifications and changes can be made within the scope of the claims.
[0051]
【The invention's effect】
As described above, the unmolded powder according to the present invention has a substantially L-shaped shape including a horizontal blind hole and a vertical blind hole communicating with the horizontal blind hole at the bottom of the horizontal blind hole. Since the holes are formed only in the mold forming process, no post-processing is required, the production time can be shortened, and as a result, it is economically advantageous as compared with processed products. In addition, since the post-processing step can be omitted, the product yield is improved, and a homogeneous powder compact can be realized.
[0052]
The molding die according to the present invention has a die, a lower punch and an upper punch fitted into the die, and moves laterally from a state stored in the die to freely project into a cavity inside the die. A horizontal pin, and a vertical pin having a fitting hole through which the horizontal pin can penetrate in a state where the horizontal pin protrudes in the cavity in the vertical direction. A homogeneous powder compact having a substantially L-shaped hole consisting of a vertical blind hole communicating with the lateral blind hole at the bottom can be manufactured with a high yield only by the die molding process.
[0053]
The method for manufacturing a powder molded body according to the present invention includes a die, a lower punch and an upper punch fitted into the die, and a laterally movable from a state stored in the die and protruding into a cavity inside the die. A state in which the horizontal pin and the vertical pin are joined after a powder material is put into the cavity of the molding die using a molding die provided with a horizontal pin and a vertical pin that can be vertically projected in the cavity. The above-mentioned powder material is compression-molded, and a powder compact having a substantially L-shaped communication hole can be produced by a production method including only a mold molding process. There are no burrs due to powder material adhering to the part, and there are advantages such as no processing and shortening of production time. As a result, it is possible to manufacture powder compacts at lower cost compared to processed products, and post processing Omit the process Can provide even product yield improved homogeneous powder compact because bets can.
[Brief description of the drawings]
FIGS. 1A and 1B are embodiments of the present invention, in which FIG. 1A is a cross-sectional view illustrating a first step related to a powder material filling operation, FIG. 1B is a cross-sectional view illustrating a second step related to an underfill operation, (C) is a sectional view showing a third step related to the horizontal pin insertion operation.
FIG. 2 is an embodiment of the present invention, in which (A) is a cross-sectional view showing a fourth step related to an upper punch transfer start operation, and (B) is a fifth step related to a powder transfer and filling operation in a cavity. FIG. 14C is a cross-sectional view showing a sixth step related to the horizontal pin bonding operation.
FIG. 3 is an embodiment of the present invention, wherein (A) is a cross-sectional view showing a seventh step relating to the simultaneous vertical compression operation, and (B) is an eighth step relating to the pressure releasing and horizontal pin releasing operation. FIG. 10C is a cross-sectional view showing a ninth step relating to the extraction (first half) operation, and FIG. 10D is a cross-sectional view showing a tenth step relating to the extraction (second half) operation.
[Explanation of symbols]
1 powder compact,
1a, 1b Powder material 2 Horizontal blind hole 3 Vertical blind hole 10 Die 11 Die hole 12 Horizontal pin hole 13 Horizontal pin 20 Lower punch 21, 31 Vertical pin hole 22 Lower vertical pin 23 Fitting hole 30 Upper punch 32 Upper vertical pin

Claims (10)

A powder compact having a horizontal blind hole, and a vertical blind hole communicating with the horizontal blind hole at the bottom of the horizontal blind hole, and formed by a mold forming process only. In a molding die having a die and a lower punch and an upper punch fitted into the die,
A lateral pin that moves laterally from a state stored in the die and can protrude into a cavity inside the die,
A molding die, comprising: a first vertical pin having a fitting hole through which the horizontal pin can penetrate in a state in which the cavity protrudes in the vertical direction. The molding die according to claim 2, further comprising a second vertical pin which is vertically coaxial with and protrudes from the cavity at a position coaxial with the first vertical pin. A die, a lower punch and an upper punch fitted into the die, a lateral pin which is moved laterally from a state of being stored in the die and which can be projected into a cavity inside the die, and which is vertically projected into the cavity. A method for producing an unmolded powder body using a molding die having a first vertical pin,
A method for producing an unmolded powder body, characterized in that after the powder material is put into the cavity of the molding die, the powder material is compression-molded in a state where the horizontal pins and the first vertical pins are connected. The first vertical pin has a fitting hole through which the horizontal pin can pass, and the first pin and the horizontal pin are coupled by fitting the horizontal pin into the fitting hole. 5. The method for producing a powder compact according to 4. The method according to claim 4, wherein the horizontal pin moves to a position immediately before a position where the horizontal pin is connected to the first vertical pin. The molding die is provided with a second vertical pin which can be protruded coaxially with the first vertical pin, and after the horizontal pin moves to a position immediately before the position where the horizontal pin is joined to the first vertical pin, The method according to claim 6, wherein the vertical pin moves to a height position that can be coupled to the horizontal pin, and the second vertical pin moves in the same direction in synchronization with the first vertical pin. 8. The method for producing a non-molded powder body according to claim 7, wherein the powder material is transferred and filled between the first vertical pin and the second vertical pin before the compression molding to uniform the powder material density. 9. The method according to claim 4, wherein the compression molding is performed such that the center of the horizontal pin is located in a neutral zone of the powder material compact. 7. After the compression molding, the horizontal pin is removed in a state where the molded body is held at an appropriate pressure by the die, the lower punch, and the upper punch to remove elastic deformation of the molding die. , 7, 8, or 9.

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