Flaskless molding machine

Abstract

A flaskless molding machine includes: an upper flask; a lower flask; a drive unit moving the lower flask; a lower filling frame; an upper plate; a lower plate; an upper flask oil-hydraulic cylinder coupled to the upper flask; a first oil-hydraulic circuit of the upper flask oil-hydraulic cylinder; a lower filling frame oil-hydraulic cylinder coupled to the lower filling frame; a second oil-hydraulic circuit of the lower filling frame oil-hydraulic cylinder; and drive units performing a squeeze process by moving the lower plate in an upward direction, wherein the first oil-hydraulic circuit includes a back pressure circuit applying a first back pressure serving as a resistance against an upward movement of the upper flask toward the upper plate, and the second oil-hydraulic circuit includes a back pressure circuit applying a second back pressure serving as a resistance against a downward movement of the lower filling frame toward the lower plate.

1 . A flaskless molding machine forming a flaskless upper mold and lower mold, comprising:
 an upper flask;   a lower flask disposed below the upper flask and capable of clamping a match plate with the upper flask;   a lower flask drive unit configured to move the lower flask in a vertical direction;   a lower filling frame disposed below the lower flask and having an upper opening capable of communicating with a lower opening of the lower flask;   an upper plate capable of entering and being retracted from the upper opening of the upper flask;   a lower plate capable of entering and being retracted from the lower opening of the lower filling frame;   an upper flask oil-hydraulic cylinder coupled to the upper flask;   a first oil-hydraulic circuit configured to move the upper flask oil-hydraulic cylinder in the vertical direction;   a lower filling frame oil-hydraulic cylinder coupled to the lower filling frame;   a second oil-hydraulic circuit configured to move the lower filling frame oil-hydraulic cylinder in the vertical direction; and   a drive unit configured to perform a squeeze process by moving the lower plate in an upward direction,   wherein the first oil-hydraulic circuit includes a first back pressure circuit configured to apply, to the upper flask oil-hydraulic cylinder, a first back pressure serving as a resistance against an upward movement of the upper flask toward the upper plate during the squeeze process of the drive unit, and   the second oil-hydraulic circuit includes a second back pressure circuit configured to apply, to the lower filling frame oil-hydraulic cylinder, a second back pressure serving as a resistance against a downward movement of the lower filling frame toward the lower plate during the squeeze process of the drive unit.   
     
     
         2 . The flaskless molding machine according to  claim 1 , wherein the first back pressure circuit and the second back pressure circuit include a counterbalance valve. 
     
     
         3 . The flaskless molding machine according to  claim 2 , wherein the counterbalance valve is an electromagnetic relief valve capable of controlling a pressure proportionally to an input voltage. 
     
     
         4 . A flaskless molding machine forming a flaskless upper mold and lower mold, comprising:
 an upper flask including a first opening, and a second opening;   a lower flask including a third opening, and a fourth opening capable of clamping a match plate with the second opening of the upper flask;   a lower filling frame including a fifth opening, and a sixth opening capable of communicating with the third opening of the lower flask;   an upper plate capable of entering and being retracted from the first opening of the upper flask;   a lower plate capable of entering and being retracted from the fifth opening of the lower filling frame;   a flask-stripping cylinder configured to adjust a positional relationship between the upper flask and the upper plate;   a first oil-hydraulic circuit configured to drive the flask-stripping cylinder;   an upper squeeze cylinder configured to move the upper plate;   a lower squeeze cylinder configured to move the lower plate; and   a squeeze oil-hydraulic circuit configured to drive the upper squeeze cylinder and the lower squeeze cylinder,   wherein the first oil-hydraulic circuit includes a first back pressure circuit configured to apply, to the flask-stripping cylinder, a first back pressure serving as a resistance against a movement of the upper plate in a direction of approaching the match plate during a squeeze process of the upper squeeze cylinder and the lower squeeze cylinder, and   the squeeze oil-hydraulic circuit includes a second back pressure circuit configured to apply, to the lower squeeze cylinder, a second back pressure serving as a resistance against a movement of the lower plate in a direction, of approaching the match plate during the squeeze process of the upper squeeze cylinder and the lower squeeze cylinder.   
     
     
         5 . A flaskless molding machine forming a flaskless upper mold and lower mold, comprising:
 an upper plate configured to form an upper molding space with a match plate and an upper flask;   a lower plate configured to form a lower molding space with the match plate and a lower flask;   a squeeze cylinder configured to apply a squeeze force to sand with which the upper molding space and the lower molding space are filled;   an oil-hydraulic circuit configured to drive the squeeze cylinder;   a first back pressure circuit configured to apply a first back pressure serving as a resistance against a movement in a direction where the upper plate and the match plate approach during a squeeze process of the squeeze cylinder; and   a second back pressure circuit configured to apply a second back pressure serving as a resistance against a movement in a direction where the lower plate and the match plate approach during the squeeze process of the squeeze cylinder.   
     
     
         6 . A flaskless molding machine forming a flaskless upper mold and lower mold, comprising:
 a pair of an upper flask and a lower flask;   a squeeze cylinder configured to perform a squeeze process of pressurizing mold sand with which the upper flask and the lower flask are filled, with a predetermined squeeze force; and   a resistance force generating mechanism configured to apply a resistance force serving as a resistance against the squeeze force during the squeeze process of the squeeze cylinder.   
     
     
         7 . A flaskless molding machine forming a flaskless upper mold and lower mold, comprising:
 a pair of an upper flask and a lower flask;   a lower filling frame communicating with the lower flask;   a squeeze cylinder configured to perform a squeeze process of pressurizing mold sand with which the upper flask, the lower flask and the lower filling frame are filled, with a predetermined squeeze force;   a first oil-hydraulic circuit configured to drive the squeeze cylinder;   a cylinder configured to move any of the upper flask, the lower flask or the lower filling frame in the squeezing direction; and   a second oil-hydraulic circuit configured to drive the cylinder, and apply a back pressure serving as a resistance against the squeeze force of the squeeze cylinder.