JP2006239700A - Method for forming powder compact, and die apparatus for powder compact - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the execution of the next forming process in the state that a lubrication layer of lubricant such as solution and dispersed liquid, has been left at forming portions. <P>SOLUTION: The solution 8 is stuck to the forming portion 2A formed on a die 2, and then water of the stuck solution 8 is evaporated and a lubrication layer 16 is formed at the forming portion 2A. After that, a powder material 6 is supplied into the forming portion 2A by means of a shoe box 7 sliding on an upper surface 3. Then, an upper punch 5 is fitted to the forming portion 2A so as to form a powder compact A. Further, when the powder compact A is taken out from the forming portion 2A afterward, before the solution 8 is stuck to the forming portion 2A in order to begin the next compacting process, the remained lubrication layer 16A left in the forming portion 2A is removed by means of a cleaning means 17. In addition, the solution 8 left on the upper surface 3 on which the shoe box 7 slides is also removed by the cleaning means 17. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for molding a powder molded body and a powder molding die apparatus.

Conventionally, in order to reduce the extraction pressure of the powder compact from the molding part of the molding die and improve the density of the powder compact, a solution in which a lubricant is dissolved in water or a molding part equipped with heating means Fill the raw material powder by spraying and adhering a dispersion liquid in which the lubricant is dispersed in water toward the molding part, evaporating the water of the solution or the water of the dispersion liquid to form a lubricating layer in the molding part. Thereafter, a molding method of a powder molded body is known in which a punch is fitted into the molded portion to mold a powder molded body, and then the powder molded body is extracted from the molded portion (for example, Patent Documents 1 and 2). ).
JP 2004-167582 A Japanese Patent Application Laid-Open No. 2004-289892

  In the prior art, the solution or dispersion is attached to the molding part to evaporate water to form a lubricating layer in the molding part, and then the raw material powder is filled in the molding part and the raw material powder is compressed by a punch. Molding and then extracting this powder compact from the molding part, then attaching the solution or dispersion again to the molding part to evaporate the water and forming a lubricating layer in the molding part, and molding the powder compact However, a lubricating layer remains on the surface of the molded part after the powder molded body is extracted, and as a result, a solution or dispersion for performing the next molding again on the remaining lubricating layer. Will be attached.

  When a further lubricating layer is formed by further adhering a solution or dispersion onto the lubricating layer remaining in such a molded part, the thickness of the lubricating layer increases and the powder compact is removed from the molded part. There is concern that the output pressure cannot be reduced or the density of the powder compact cannot be improved.

  Furthermore, in such a molding method, the raw material powder is filled in the molding part by a raw material supply body that slides on the upper surface of the mold body. However, if the upper surface becomes dirty with the lubricating liquid, the raw material supply body slides. There was also a fear that it could not be performed well.

  The problem to be solved is that the next molding is not performed while the lubricating layer of the lubricating liquid such as a solution or dispersion remains in the molding portion. This is to prevent the next raw material supplier from sliding while the lubricating liquid or lubricating layer such as solution or dispersion remains on the upper surface of the mold body.

  According to the first aspect of the present invention, a lubricating liquid is adhered to a molding part formed on a molding die body, and a liquid layer of the adhered lubricating liquid is evaporated to form a lubricating layer on the molding part. In the molding method of the powder molded body, the powder is then molded into the molded part by fitting the punch into the molded part, and then the powder molded body is taken out from the molded part. A method for forming a powder molded body, comprising removing the lubricant layer after taking out remaining in the molded portion before adhering to the molded portion.

  According to the second aspect of the present invention, a lubricating liquid is adhered to a molding part formed on the mold body, and a liquid layer of the adhered lubricating liquid is evaporated to form a lubricating layer on the molding part. Powder molding in which the raw material powder is filled into the molding part by a raw material supply body that slides, and thereafter a punch is fitted into the molding part to form a powder compact, and thereafter the powder compact is taken out from the molding part. In the method for forming a body, the lubricating liquid or the lubricating layer remaining on the upper surface is removed before the raw material supply body is slid on the upper surface.

  The invention according to claim 3 is characterized in that the lubricating liquid is a solution in which a lubricant is dissolved in a solvent or a dispersion liquid in which a lubricant is dispersed in a solvent, and the lubricating liquid is removed through the solvent. Item 3. A method for forming a powder compact according to Item 1 or 2.

  According to a fourth aspect of the present invention, there is provided a molding die body having a through hole formed vertically on the upper surface thereof, a lower punch fitted into the through hole from below, and fitted into the through hole from above. A powder mold apparatus comprising an upper punch, an attaching means provided in the through-hole for attaching a lubricating liquid to the through-hole, and a cleaning means for the through-hole.

  According to a fifth aspect of the present invention, there is provided a molding die body having a through hole that vertically forms a side surface of a powder molded body, a lower punch that fits into the through hole from below, and a fitting into the through hole from above. An upper punch, an attaching means provided in the through-hole for adhering the lubricating liquid to the through-hole, a raw material supply body slidably provided on the upper surface and supplying raw material powder, and a cleaning means provided on the upper surface It is the powder molding die apparatus characterized by including.

  A sixth aspect of the present invention is the powder molding die apparatus according to the fourth or fifth aspect, wherein the cleaning means is provided with a wiping tool.

  According to the first aspect of the present invention, the remaining lubricating layer is removed by the cleaning means, and in the next molding, the solution adheres directly to the surface of the molded part, and a new lubricating layer can be generated.

  According to the invention of claim 2, the lubricating liquid and the lubricating layer adhering to the upper surface can be removed by the cleaning means, and the slidability of the upper surface of the raw material supply body can be ensured.

  According to the invention of claim 3, cleaning can be efficiently performed by dissolving the lubricant.

  According to the invention of claim 4, by providing the cleaning means, it is possible to remove the remaining lubricating layer and generate a new lubricating layer.

  According to the invention of claim 5, by providing the cleaning means, it is possible to remove the lubricant on the upper surface and ensure the sliding of the raw material supply body on the upper surface.

  According to invention of Claim 6, it can clean by scraping off with the movement of a wiping tool.

  Preferred embodiments of the present invention will be described with reference to the accompanying drawings. The embodiments described below do not limit the contents of the present invention described in the claims. In addition, all of the configurations described below are not necessarily essential requirements of the present invention.

  1 to 7 show the first embodiment, and FIG. 1 shows the first step. In FIG. 1, 1 is a die that is a molding die body that molds a side surface of a powder compact A, which will be described later. 2 is a through hole which is a forming part formed through the upper surface 3 in the vertical direction. The lower punch 4 is fitted from below the through hole 1, and the upper punch 5 is fitted from above the through hole 1. It has become. Further, a box-like shoe box 7 for supplying a raw material powder 6 mainly composed of metal powder is slidably provided on the upper surface 3 of the die 2. Further, a nozzle 9 is provided above the through hole 1 as an injection means for adhering a solution 8 as a lubricating liquid obtained by dissolving a lubricant in water as a solvent to the through hole 1. Instead of the solution 8, a dispersion liquid in which a lubricant is dispersed in water as a solvent may be used. Further, as the lubricating liquid, a solution obtained by dissolving zinc stearate with an organic solvent such as acetone may be used. Further, a molding part heating means 10 is provided around the molding part 2A of the powder molded body A defined by the through hole 1 and the lower punch 4 fitted in the through hole 1, and the molding part heating means 10 is provided. Is connected to the molding part heating temperature control means 11, and the molding part heating temperature control means 11 controls the surface temperature of the through-hole 1 to be higher than the evaporation temperature of the water in the solution 8 and lower than the melting temperature of the lubricant. I am doing so.

  In addition, the nozzle 9 serving as the injection means is provided on the left and right above the through-hole 1 so that the nozzle port 12 faces the through-hole 1, and a tank-like storage portion 13 that stores the solution 8 is illustrated. It is connected to the nozzle 9 via a pipe-like supply path 14 equipped with a supply pump that does not. The adhering means 15 for the solution 8 is formed by the nozzles 9 provided so as to face the storage part 13, the supply path 14, and the molding part 2A.

  Further, on one side of the upper surface 3, a cleaning means 17 that is inserted into the through hole 1 to remove a lubricating layer 16A remaining on the surface of the forming portion 2A described later is removed via a moving means 18 such as a robot arm. Is provided. The cleaning means 17 has, for example, a rotary shaft 19 arranged in the vertical direction, and an upper portion thereof is connected to a rotary drive device 20 such as a motor. Further, the rotary shaft 19 has a wiping tool 21 such as a sponge, cloth, or brush. It is provided along the rotation axis 20. The wiping tool 21 has such a hardness that it can be rubbed against the surface of the molded part 1A. The wiping tool 21 has a vertical length longer than the vertical length of the through-hole 1, The width of the wiping tool 21 is substantially the same as or slightly larger than the radius of the through-hole 2 so that the lateral tip of the wiping tool 21 can contact the inner surface of the through-hole 2.

  In the first step, the surface of the through-hole 1 is higher than the water evaporation temperature of the solution 8 by the heat of the molding part heating means 10 controlled in advance by the molding part heating temperature control means 11, and the melting temperature of the lubricant. Is set lower. In a state where the lower punch 4 is fitted in the through hole 1 of the die 2 and the forming part 2A is formed, the supply pump is operated to spray the solution 8 in the storage part 13 as a mist from the nozzle port 12 of the nozzle 9. To do. This solution 8 is sprayed and adhered to the molding part 2A of the die 2 heated by the molding part heating means 10. For this reason, the solution 8 adheres almost uniformly to the surface of the molding portion 2A of the die 2 provided in the through hole 1, and the water evaporates, so that the solution 8 dries and crystals grow on the entire surface. The crystallization layer as the lubricant layer 16 of the lubricant is uniformly formed.

  Next, as shown in the second step of FIG. 2, the shoe box 7 moves forward to drop the raw material powder 6 into the molding part 2A and fill it. Next, as shown in the third step of FIG. 3, the die 2 is moved downward, and the upper punch 5 is inserted into the molding portion 2 </ b> A of the through hole 1 from above, and is sandwiched between the upper punch 5 and the lower punch 4. In this way, the raw material powder 6 is compressed. At this time, the lower punch 4 is fixed at the lower end so as not to move. In the third step, the raw material powder 6 is compressed in a lubricated state into a crystallization layer (lubricant layer 16) formed of a lubricant.

  In the powder compact A thus press-molded, the die 2 is further lowered, and the upper surface 3 of the lower punch 4 is substantially level with the upper surface 3 of the die 2 as shown in the fourth step of FIG. When it becomes, it can be removed and taken out. Even during the removal, the powder compact A comes into contact with the crystallization layer (lubricant layer 16) formed of the lubricant in a lubricated state, and most of the lubricant layer 16 is peeled off. After the powder molded body A is taken out, the lubricating layer 16A may remain in a part of the molded portion 2A. When a new lubricating layer 16 is generated while leaving the remaining lubricating layer 16A, the thickness of the lubricating layer 16A is reduced. It becomes large and causes a harmful effect in the next molding.

  Accordingly, after the powder compact A is taken out, the moving means 18 is used as the fifth step shown in FIGS. The wiping tool 21 is inserted into the through hole 2 by. At this time, the rotating shaft 19 is made to substantially coincide with the axis of the through hole 1. As a result, the lateral tip of the wiping tool 21 contacts the inner surface of the through hole 2. At this time, the wiping tool 21 is preliminarily impregnated with water which is the solvent of the solution 8, preferably about 60 to 95 ° C. When the rotary drive device 20 is operated, the rotary shaft 19 rotates, and as a result, the tip of the wiping tool 21 slides on the surface of the molding part 2A, and the residual lubricating layer 16A is formed by the water as the solvent contained in the wiping tool 21. It is melted, dropped and removed. In particular, when hot water of about 60 to 95 ° C. is contained in the wiping tool 21, it can be dissolved more reliably. The remaining lubricating layer 16A is scraped off and removed by the tip of the rotating wiping tool 21.

  The fifth step of removing the residual lubricating layer 16A may be performed every several times during the repeated molding cycle, for example, every two molding cycles instead of every molding cycle.

  With the residual lubricant layer 16A removed in this manner, the process returns to the first step again, and after the solution 8 is sprayed on the molded part 2A again to form a crystallization layer, the raw material powder 6 is filled into the molded part 2A. It is what is done.

  Incidentally, the solution 8 ejected from the nozzle port 12 of the ejection means 15 spreads and adheres to the upper surface 3, and the lubricating layer gradually becomes thicker. As a countermeasure against such contamination, FIG. As shown in FIG. 4, the lower end of the wiping tool 21 is brought into contact with the upper surface 3 by the moving means 18, and the rotating shaft 19 is rotated by the rotary drive device 20, so that the dirt on the upper surface 3 is scraped off by the lower end of the wiping tool 21. Alternatively, the dirt is dissolved and removed with water as a solvent contained in the wiping tool 21. In particular, when hot water of about 60 to 95 ° C. is contained in the wiping tool 21, it can be dissolved more reliably. And this upper surface cleaning process may be performed every several times in the middle of repeated molding cycles, for example, every two molding cycles instead of every molding cycle.

  As mentioned above, in the said Example, the die | dye 2 which has the through-hole 1 which forms the side surface of the powder compact A vertically in the upper surface 3, the lower punch 4 fitted to the said through-hole 1 from the bottom, An upper punch 5 fitted into the through-hole 1 from above, an attachment means 15 provided in the through-hole 1 for adhering a solution 8 in which a lubricant is dissolved in water, and the cleaning of the through-hole 1 Means 17 is provided, and the solution 8 is adhered to the molding part 2A formed on the die 2, and the lubricant layer 16 is formed on the molding part 2A by evaporating the moisture of the adhered solution 8, and then the raw material powder 7 is molded. To fill the portion 2A, and then fit the upper punch 5 to the molding portion 2A to form the powder compact A, and then to start the next molding when the powder compact A is taken out from the molding portion 2A. The solution 8 remains in the molding part 2A before adhering to the molding part 2A. By removing the remaining lubricating layer 16A after taking out, in the next molding, the solution 8 adheres directly to the surface of the molded part 2A, and a new lubricating layer 16 can be generated. Evil can be eliminated.

  In addition, in the above embodiment, the raw material powder 6 is supplied to the molding part 2A by the shoe box 7 slidably provided on the upper surface 3, and the upper surface 3 is provided with the cleaning means 17, so that it adheres to the upper surface 3. Dirt such as the solution 8 can be removed, and the slidability of the upper surface 3 in the shoe box 7 can be ensured.

  In the case of the solution 8 in which the lubricant is dissolved in water (solvent) or in the case of a dispersion in which the lubricant is dispersed in water (solvent), the water as the solvent, preferably hot water as the warmed solvent, is used. Can be applied to the remaining lubricating layer 16A and efficiently melted to clean the molded part 2A.

  Further, the cleaning means 17 is provided with a wiping tool 21, which is moved in the molding part 2A, so that the remaining lubricating layer 16A is scraped off to clean the molding part 2A.

  As described above, the molded body according to the present invention can be applied to various uses.

It is a longitudinal cross-sectional view which shows the 1st process which shows Example 1 of this invention. It is a longitudinal cross-sectional view which shows the 2nd process which shows Example 1 of this invention. It is a longitudinal cross-sectional view which shows the 3rd process which shows Example 1 of this invention. It is a longitudinal cross-sectional view which shows the 4th process which shows Example 1 of this invention. It is a longitudinal cross-sectional view which shows the 5th process which shows Example 1 of this invention. It is a cross-sectional view showing a fifth step showing Example 1 of the present invention. It is a longitudinal cross-sectional view which shows the cleaning of the upper surface which shows Example 1 of this invention.

Explanation of symbols

1 Through hole 2 Die (mold body)
2A Molding part 3 Upper surface 4 Lower punch 5 Upper punch 6 Raw material powder 7 Shoe box (raw material supply body)
8 Solution (Lubricant)
16 Lubrication layer
16A Remaining lubrication layer
17 Cleaning means
21 Wiping tool A Powder compact

Claims (6)

  Lubricating liquid is attached to the molding part formed on the mold body, and the liquid component of the adhering lubricating liquid is evaporated to form a lubricating layer on the molding part, and then the raw material powder is filled into the molding part and then punched. In a molding method of a powder molded body, in which a powder molded body is taken out from the molded portion and then the lubricating liquid is adhered to the molded portion. A method for forming a powder molded body, comprising removing the lubricating layer after removal remaining in a portion.   A raw material supplier that slides on the upper surface of the mold body after a lubricating liquid is adhered to the molding part formed on the molding body and the lubricant layer is evaporated to form a lubricating layer on the molding part. In the molding method of the powder molded body, the raw material powder is filled in the molded portion, and then a punch is fitted into the molded portion to mold a powder molded body, and then the powder molded body is taken out from the molded portion. A method for forming a powder molded body, comprising: removing the lubricating liquid or the lubricating layer remaining on the upper surface before sliding the raw material supply body on the upper surface.   The powder according to claim 1 or 2, wherein the lubricating liquid is a solution obtained by dissolving a lubricant in a solvent or a dispersion liquid obtained by dispersing a lubricant in a solvent, and the lubricating liquid is removed through the solvent. Molding method of the molded body.   A mold main body having a through hole that vertically forms a side surface of the powder molded body, a lower punch that fits into the through hole from below, an upper punch that fits into the through hole from above, and the through hole An apparatus for forming a powder mold, comprising: an attaching means for attaching a lubricating liquid to the through hole provided in the hole; and a cleaning means for the through hole.   A molding die main body having a through hole that vertically forms a side surface of the powder molded body, a lower punch that fits into the through hole from below, an upper punch that fits into the through hole from above, and the penetration An adhesion means for adhering a lubricating liquid to the through-hole provided in the hole; a raw material supply body slidably provided on the upper surface for supplying the raw material powder; and a cleaning means provided on the upper surface. Powder molding die equipment. 6. The powder molding die apparatus according to claim 4, wherein the cleaning means is provided with a wiping tool.

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