US-12623383-B2 - Plasticizing device

US12623383B2US 12623383 B2US12623383 B2US 12623383B2US-12623383-B2

Abstract

A plasticizing device includes a flat screw that has a groove formation surface formed with a groove and is rotated about a rotation axis, a barrel that has a facing surface facing the groove formation surface and is formed with a communication hole, and a heating unit configured to heat a material supplied between the flat screw and the barrel. The barrel has a separate structure including a first member having the facing surface and a second member separated from the facing surface, a space is defined between the first member and the second member, and the heating unit is disposed in the second member.

Inventors

Masayuki Takahashi

Assignees

SEIKO EPSON CORPORATION

Dates

Publication Date: 20260512
Application Date: 20240227
Priority Date: 20230228

Claims (6)

1 . A plasticizing device comprising: a flat screw that has a groove formation surface formed with a groove and is rotated about a rotation axis; a barrel that has a facing surface facing the groove formation surface and is formed with a communication hole; and a heating unit configured to heat a material supplied between the flat screw and the barrel, wherein the barrel has a separate structure including a first member having the facing surface and a second member separated from the facing surface, a space is defined between the first member and the second member, the heating unit is disposed in the second member, a cooling flow path through which a cooling medium flows is formed along an outer periphery of the flat screw, and the barrel is provided with a hole through which the cooling flow path communicates with the space.
2 . The plasticizing device according to claim 1 , wherein the barrel is provided with a hole through which the space communicates with outside.
3 . The plasticizing device according to claim 1 , wherein a plurality of the spaces are defined, and the plurality of spaces communicate with one another through a hole.
4 . The plasticizing device according to claim 1 , wherein the first member has a convex shape in which a thickness increases from an outer periphery toward a center when viewed from a direction orthogonal to the rotation axis.
5 . The plasticizing device according to claim 1 , wherein the first member has a first region including the communication hole and a second region surrounding the first region, and a sum of volumes of the space in the first region is larger than a sum of volumes of the space in the second region.
6 . The plasticizing device according to claim 1 , wherein the heating unit includes a plurality of rod-shaped heaters disposed symmetrically relative to the communication hole along the facing surface, and a proportion of portions of the space overlapping with the rod-shaped heaters is larger than a proportion of portions of the space not overlapping with the rod-shaped heaters when viewed along a direction of the rotation axis.

Description

The present application is based on, and claims priority from JP Application Serial Number 2023-029313, filed Feb. 28, 2023, the disclosure of which is hereby incorporated by reference herein in its entirety. BACKGROUND 1. Technical Field The present disclosure relates to a plasticizing device. 2. Related Art In order to reduce a size of an injection molding machine, a plasticizing device in which a screw in the related art is replaced with a rotor has been proposed. For example, JP-A-2022-83026 discloses a plasticizing device including a screw that has a groove formation surface formed with a groove and a barrel that has a facing surface facing the groove formation surface and is provided with a heater and a communication hole. According to JP-A-2022-83026, the barrel includes a first member and a second member having a thermal conductivity different from that of the first member, and the second member is provided closer to the communication hole than the first member. Accordingly, stabilized plasticization can be achieved by providing a temperature difference between a temperature of the communication hole and a temperature of an outer periphery of the barrel and appropriately controlling a temperature gradient from the outer periphery of the barrel toward the communication hole. JP-A-2022-83026 is an example of the related art. However, the plasticizing device disclosed in JP-A-2022-83026 needs to be improved. Specifically, when the barrel is formed of members having different thermal conductivities, since thermal expansion coefficients of the members are different, distortion may occur in the barrel under a high-temperature condition. That is, a plasticizing device having high reliability under a high-temperature condition and stabilized plasticizing performance is required. SUMMARY A plasticizing device according to an aspect of the disclosure includes a flat screw that has a groove formation surface formed with a groove and is rotated about a rotation axis, a barrel that has a facing surface facing the groove formation surface and is formed with a communication hole, and a heating unit configured to heat a material supplied between the flat screw and the barrel. The barrel has a separate structure including a first member having the facing surface and a second member separated from the facing surface, a space is defined between the first member and the second member, and the heating unit is disposed in the second member. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an injection molding device according to a first embodiment. FIG. 2 is a cross-sectional view showing a schematic configuration of a plasticizing device. FIG. 3 is a perspective view showing a screw. FIG. 4 is a plan view showing a barrel. FIG. 5 is an exploded view showing the barrel. FIG. 6 is a transparent plan view showing the inside of the barrel. FIG. 7 is a cross-sectional view showing the barrel taken along a line b-b shown in FIG. 4. FIG. 8 is a perspective view showing a first member as viewed from a back surface. FIG. 9 is a plan view showing an arrangement pattern of gap portions. FIG. 10 is a temperature distribution diagram showing a simulation result of a temperature distribution of the barrel. FIG. 11 is a temperature distribution diagram showing a simulation result of a temperature distribution of a barrel in a comparative example. FIG. 12 is a plan view showing an arrangement pattern of gap portions according to a second embodiment. FIG. 13 is a cross-sectional view showing the barrel. FIG. 14 is a schematic configuration diagram of a three-dimensional fabrication device according to a third embodiment. FIG. 15 is a plan view showing an arrangement pattern of gap portions according to a modification. FIG. 16 is a plan view showing a different arrangement pattern of gap portions according to a modification. DESCRIPTION OF EMBODIMENTS First Embodiment Outline of Injection Molding Device FIG. 1 is a perspective view showing a schematic configuration of an injection molding device according to a first embodiment. As shown in FIG. 1, an injection molding device 200 according to the embodiment includes a plasticizing device 100, a mold clamping device 130, a mold 160, and a control unit 190. An X axis, a Y axis, and a Z axis which are three axes orthogonal to one another are shown in the drawings. Specifically, an extending direction of the mold clamping device 130 is a Y positive direction, and an extending direction of a hopper 70 of the plasticizing device 100 is a Z positive direction. The injection molding device 200 injects a molding material plasticized by the plasticizing device 100 into the mold 160 through a nozzle portion 114 (FIG. 2) to form a molded product. Operations of the plasticizing device 100 and the mold clamping device 130 are controlled by the control unit 190. The control unit 190 is implemented as a computer including a CPU and a memory, and controls units of the injection moldi