JP2020090035A5 - - Google Patents

Description

In order to solve the above problems, in the present invention, the injection molding mold includes a shape piece provided with a transfer surface and a base portion for supporting the shape piece, and the transfer surface of the shape piece and the base portion thereof. , wherein Rukoto is constituted by an elastic structure part is elastically deformed in accordance with the injection pressure and holding pressure of resin injected into the mold to shape recovery following the shrinkage of the resin due to cooling between the And.

Claims (16)

An injection molding die including a shape piece having a transfer surface, a base supporting the shape piece, and an elastic structure provided between the shape piece and the base in the mold clamping direction.
The elastic structure is an injection-molded mold that elastically deforms according to the injection pressure and holding pressure of the resin injected into the mold and recovers its shape following the shrinkage of the resin due to cooling. In the injection molding die according to claim 1, the elastic structure is an injection molding die in which an urging force corresponding to the amount of deformation of the elastic structure is applied to the shape piece . The injection molding die according to claim 1 or 2, wherein the shape piece elastically deforms according to the shrinkage of the resin . In the injection molding die according to any one of claims 1 to 3, a portion of the transfer surface of the shape piece and a portion between the base portion thereof are configured by the elastic structure having different spring constants. Injection molding mold that has been. In the injection molding mold according to any one of claims 1 to 4, the shape piece is the first shape piece, the elastic structure is the first elastic structure, and the transfer of the first shape piece. A second shape piece having a transfer surface that is not parallel to the surface and a second elastic structure that elastically supports the second shape piece and has an elastic deformation direction different from that of the first elastic structure. Injection molding mold. The injection molding die according to claim 5, wherein the first and second elastic structures have different spring constants from each other. In the injection molding mold according to claim 5 or 6, the first and second elastic structures have contact portions that come into contact with each other, and injections that transmit elastic forces to each other through the contact portions. Molding mold. The injection molding die according to any one of claims 1 to 7, wherein a passage for circulating a cooling fluid is arranged inside the elastic structure. The injection molding die according to any one of claims 1 to 8, wherein the surface of the elastic structure has a heat sink structure. The injection molding die according to any one of claims 1 to 9 , wherein the elastic structure has a lattice structure . In the injection molding mold according to any one of claims 1 to 10, the change in specific volume of the resin during shrinkage, which is determined based on the pressure (P) -volume (V) -temperature (T) characteristics of the resin, is determined. ΔV, the internal pressure in the mold is P, the shrinkage rate of the resin along the direction of deformation of the elastic structure at that time is Δt, and the calibration coefficient q is
q = ΔV / Δt ... (1)
The spring coefficient k of the elastic structure is
k = q-1 × ΔV / P ... (2)
Injection molding mold. In the injection molding mold according to any one of claims 1 to 11, the in-mold pressure generated by the load P of the holding pressure on the resin in the mold and the pressure (P) -volume (V) -temperature of the resin. (T) The relationship between the shrinkage amount ΔV at the time of shrinkage of the resin obtained from the characteristics and the deformation amount ΔD when the load P is applied to the elastic structure is
ΔD = QΔV (1.0 ≦ Q ≦ 1.25)… (3)
Injection molding mold . In the injection molding die according to any one of claims 1 to 12, the in-mold pressure and the resin pressure (P) generated by the holding pressure load P1 from the molten state to the glass transition temperature of the resin in the mold. )-Volume (V) -Temperature (T) The shrinkage amount ΔV1 of the resin from the molten state to the glass transition temperature obtained from the characteristics, and the deformation amount ΔD1 when the load P1 is applied to the elastic structure. Relationship
ΔD1 = Q1ΔV1 (where 1.0 ≦ Q1 ≦ 1.1)… (4)
And, the glass transition obtained from the in-mold pressure and the pressure (P) -volume (V) -temperature (T) characteristics of the resin caused by the load P2 of the holding pressure from the glass transition temperature of the resin to reaching room temperature. The relationship between the shrinkage amount ΔV2 of the resin from the temperature to the room temperature and the deformation amount ΔD2 when the load P2 is applied to the elastic structure is
ΔD2 = Q2ΔV2 (where 1.0 ≦ Q2 ≦ 1.25)… (5)
Injection molding mold . The method for manufacturing an injection mold according to any one of claims 1 to 11, wherein the method for manufacturing an injection mold includes a step of molding the elastic structure by a laminated molding method . An injection molding machine comprising the injection molding die according to any one of claims 1 to 13 and an injection device for injecting molten resin into the injection molding die. A method for manufacturing a resin molded product, wherein a molten resin is injected into the injection molding mold according to any one of claims 1 to 13 by an injection device, and the resin molded product is injection-molded.