High-density molding device and high-density molding method for mixed powder

Abstract

A mixed powder placed in a container cavity is transferred to the cavity of a first die. A first pressure is applied to the mixed powder in the first die to form an intermediate green compact. The first die and the intermediate green compact are heated to heat the intermediate green compact to the melting point of a lubricant. The heated intermediate green compact is transferred to the cavity of a second die, and a second pressure is applied to the intermediate green compact to form a high-density final green compact.

1 . A mixed powder high-density molding method comprising:
 filling a container cavity of a container with a mixed powder that is a mixture of a basic metal powder and a low-melting-point lubricant powder;   transferring the mixed powder in the container cavity to a cavity of a first die that is positioned with respect to the container;   applying a first pressure to the mixed powder in the cavity of the first die to form a mixed powder intermediate compressed body;   heating the first die and the mixed powder intermediate compressed body to heat the mixed powder intermediate compressed body to a melting point of the lubricant powder; positioning the heated mixed powder intermediate compressed body with respect to a second die together with the first die;   transferring the mixed powder intermediate compressed body in the cavity of the first die to a cavity of the second die that is positioned with respect to the first die; and   applying a second pressure to the mixed powder intermediate compressed body in the cavity of the second die to form a high-density mixed powder final compressed body.   
     
     
         2 . The mixed powder high-density molding method as defined in  claim 1 ,
 wherein the lubricant powder has a low melting point within a range of 90 to 190° C.   
     
     
         3 . The mixed powder high-density molding method as defined in  claim 1 ,
 wherein the second die is pre-heated before the mixed powder intermediate compressed body is placed in the second die.   
     
     
         4 . The mixed powder high-density molding method as defined in  claim 1 ,
 wherein the first die is pre-heated after the mixed powder intermediate compressed body has been molded.   
     
     
         5 . The mixed powder high-density molding method as defined in  claim 1 ,
 wherein the second pressure is selected to be equal to the first pressure.   
     
     
         6 . A mixed powder high-density molding system comprising:
 a mixed powder feeding device that can fill a container cavity of a container that is positioned at a mixed powder filling position with a mixed powder that is a mixture of a basic metal powder and a low-melting-point lubricant powder;   a mixed powder transfer device that transfers the mixed powder in the container cavity to a cavity of a first die that is positioned with respect to the container;   a first press molding device that applies a first pressure to the mixed powder in the cavity of the first die from a first punch to form a mixed powder intermediate compressed body;   a heating device that heats the first die positioned at a heating position and the mixed powder intermediate compressed body to heat the mixed powder intermediate compressed body to a melting point of the lubricant powder;   an intermediate green compact transfer device that transfers the mixed powder intermediate compressed body in the cavity of the first die to a second die positioned at a transfer relay position;   a second press molding device that applies a second pressure to the mixed powder intermediate compressed body in a cavity of the second die positioned at a final compressed body molding position to form a high-density mixed powder final compressed body; and   a product discharge device that is configured to discharge the mixed powder final compressed body in the cavity of the second die at a product discharge position.   
     
     
         7 . The mixed powder high-density molding system as defined in  claim 6 , comprising:
 a first die transfer device that is configured to transfer the first die to position the first die with respect to the container that is positioned at the mixed powder filling position;   an unheated green compact transfer device that is configured to transfer the first die from an intermediate green compact molding position, to position the first die at the heating position;   a heated green compact transfer device that is configured to transfer the first die that holds the mixed powder intermediate compressed body from the heating position, to position the first die at the transfer relay position;   a second die transfer device that is configured to transfer the second die that holds the mixed powder intermediate compressed body from the transfer relay position, to position the second die at the final green compact molding position;   a final green compact transfer device that is configured to transfer the second die that holds the mixed powder final compressed body from the final green compact molding position, to position the second die at the product discharge position; and   a second die return transfer device that is configured to transfer the second die that holds the mixed powder final compressed body from the product discharge position, to position the second die at a reception relay position.   
     
     
         8 . The mixed powder high-density molding system as defined in  claim 7 ,
 wherein the mixed powder filling position, the heating position, and the transfer relay position are separately provided along a first circular path defined around a first axis, and the reception relay position, the final green compact molding position, and the product discharge position are separately provided along a second circular path defined around a second axis,   the first die transfer device, the unheated green compact transfer device, and the heated green compact transfer device are implemented by utilizing a first rotary table that can be rotated around the first axis, and   the second die transfer device, the final green compact transfer device, and the second die return transfer device are implemented by utilizing a second rotary table that can be rotated around the second axis.   
     
     
         9 . The mixed powder high-density molding system as defined in  claim 6 , further comprising:
 a first pre-heating device that pre-heats the first die.   
     
     
         10 . The mixed powder high-density molding system as defined in  claim 6 , further comprising:
 a second pre-heating device that pre-heats the second die.