In the process of two-direction pressing, the die is inserted with tungsten carbide punch. The punch is composed of the lower steel substrate and the upper tungsten carbide punch, of which the connection is using the bonding of alloy and matrix. Bonding method is that the inorganic adhesive is used to adjust it to the paste, coated in the joint, the electric furnace is heated, and can be followed up after curing, of which the clearance is generally 0.2-0.3mm.

 

During the mold processing, there will be a certain chemical reaction between the adhesive and the cooling medium of the equipment, which will cause pollution to the cooling medium and even affect the performance of the processing equipment. Especially for the precision mold processing equipment, it is not allowed the pollution of the cooling medium. When the mold is in the rough cutting shape, the adhesive is not conductive, it must be removed manually, and then the mold processing is affected. Because the punch alloy and the matrix are bonded to the matrix, there is a 0.2-0.3 gap, the position error of the punch head is large, and the processing quantity is increased.

 

 

To solve this problem, a variety of two-way pressing tungsten carbide dies have been designed, including inner cylinder mould, die cushion, upper plunger die, and lower plunger die. The inner cylinder die is arranged above the mold pad while the upper die is inserted in the inner circular hole of the inner cylinder die. And the lower punch die is inserted in the inner circular hole of the inner cylinder mould through the inner hole of the mould pad. The lower die includes the hard alloy punch, the steel matrix, the first connection hole and the second connecting hole; the lower end of the cemented carbide punch is at the lower end. The setting has an inlaid section, the insert section is in interference with the concave hole of the steel matrix, and the inserting section is connected to the concave hole of the steel matrix; the first connection aperture is inlaid to the lower end of the cemented carbide punch, and the second connection aperture is positioned on the steel matrix and the first connection hole and the second connection hole, thus corresponding to the phase.

 

Compared with conventional technology, two-direction pressing of tungsten carbide dies can improve the stability of the pressing and eliminate the phenomenon of alloy falling off. What’s more, it avoids the harm of the punch to the processing equipment and the pollution caused by the punch. It can effectively improve the quality of the product as well.