Patent Application
20230382033
This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2022-084919 filed on May 25, 2022, the entire content of which is incorporated herein by reference.
The present disclosure relates to a heating cylinder heater for heating a heating cylinder of an injection molding machine, an injection apparatus including a heating cylinder heater, and an injection molding machine.
An injection molding machine includes an injection apparatus and a mold clamping device. The injection apparatus includes a heating cylinder and a screw placed in the heating cylinder. A band heater is provided in the heating cylinder. The heating cylinder is heated by the band heater, an injection material is supplied, and the screw is rotated. Then, the injection material is melted by heat generated by the band heater and shear heat generated by the rotation of the screw, and injection material is metered.
JPS59-184623U describes a heating cylinder heater including an infrared heater. The heating cylinder heater described in JPS59-184623U includes a plurality of infrared rays provided outside the heating cylinder in a non-contact manner, and a heat insulating material provided outside the infrared heater. When a current is supplied to the infrared heater, the heating cylinder is heated by the infrared rays.
Both the band heater and the heating cylinder heater described in JPS59-184623U are excellent because the heating cylinder can be appropriately heated. However, there is also a problem to be solved. In some cases, the heating cylinder may generate heat due to a shearing force generated in the injection material by rotating the screw and become higher in temperature than a target temperature depending on the position. In particular, the temperature is likely to rise at a center position of the heating cylinder. For example, when the heating cylinder is provided with the band heater, cold air can be blown from the outside of the band heater, but the heat insulating material provided on the band heater prevents efficient cooling. There is a problem that there is no unit for cooling the heating cylinder heater described in JPS59-184623U.
Illustrative aspects of the present disclosure provide a heating cylinder heater that can perform cooling appropriately.
Other problems and novel features will become apparent from description of the present description and the accompanying drawings.
According to one illustrative aspect of the present disclosure, a heating cylinder heater includes a plurality of infrared heaters disposed around a heating cylinder in a non-contact manner with respect to the heating cylinder, a heat insulating material provided outside the infrared heaters, and a cover configured to cover the heat insulating material. The cover has two or more opening portions, and a part or all of the two or more opening portions are each provided with an opening-closing device that is configured to open and close the opening portion.
According to the illustrative aspect of the present disclosure, a heating cylinder can be efficiently cooled.
Hereinafter, specific illustrative embodiments will be described in detail with reference to the drawings. The present disclosure is not limited to the following illustrative embodiments. In order to clarify the description, the following description and the drawings are simplified as appropriate. In the drawings, the same elements are denoted by the same reference numerals, and repeated description thereof is omitted as necessary. Further, hatching may be omitted so as not to complicate the drawings.
As shown in
The mold clamping device 2 includes a fixed plate 7 fixed to a bed B, a movable plate 8 slidably provided on the bed B, and a mold clamping housing 9. The fixed plate 7 and the mold clamping housing 9 are coupled to each other by a plurality of tie bars 11, 11, . . . . The movable plate 8 is slidable between the fixed plate 7 and the mold clamping housing 9. A mold clamping mechanism is provided between the mold clamping housing 9 and the movable plate 8, that is, in the present illustrative embodiment, a toggle mechanism 13 is provided. A mold 15 on a fixed side and a mold 16 on a movable side are provided on the fixed plate 7 and the movable plate 8, respectively. Therefore, the molds 15 and 16 are opened and closed when the toggle mechanism 13 is driven.
The injection apparatus 3 includes a heating cylinder 19, a screw 20 provided in the heating cylinder 19, and a screw driving device 22. The heating cylinder 19 is supported by the screw driving device 22. The screw 20 is driven by the screw driving device 22 in a rotational direction and an axial direction. The heating cylinder 19 is provided with a hopper 23 and an injection nozzle 24.
The heating cylinder heater 30 according to the present illustrative embodiment will be described. As shown in
As shown in
In the present illustrative embodiment, one opening portion 39 is formed at a lower part of the cover 32, and one opening portion 40 is formed at an upper part of the cover 32. The opening portions 39 and 40 penetrate the heat insulating material 34 and communicate with a space surrounded by the inside of the heat insulating material 34 and an outer circumferential surface of the heating cylinder 19. Of the opening portions 39 and 40, the opening portion 39 at the lower part is normally open, and the opening portion 40 at the upper part is provided with an opening-closing unit 42 configured to open and close the opening portion 40. The opening-closing unit 42 includes a lid 43 that closes the opening portion 40, a cylinder unit 44 configured to drive the lid 43, and a bracket 45 that supports the cylinder unit 44. The cylinder unit 44 is driven by the control device 4. When the cylinder unit 44 is driven, the opening portion 40 is opened and closed by the lid 43. The opening portions 39 and 40 and the opening-closing unit 42 serve as a cooling unit for cooling the heating cylinder 19.
In the present illustrative embodiment, as shown in
As described above, since the second heating cylinder heater 30H2 is configured similarly to the third heating cylinder heater 30H3, the description thereof is omitted. The first heating cylinder heater 30H1 and the fourth heating cylinder heater 30H4 have a configuration similar to that of the third heating cylinder heater 30H3, but is partially different. Specifically, the opening portions 39 and 40 are not formed, and the opening-closing unit 42 is not provided. That is, the first heating cylinder heater 30H1 and the fourth heating cylinder heater 30H4 are not provided with the cooling unit for cooling the heating cylinder 19. A reason why the first heating cylinder heater 30H1 is not provided with the cooling unit is that a portion of the heating cylinder 19 near the hopper 23 is relatively easy to be cooled as heat is transferred to the screw driving device 22 by heat conduction. A reason why the fourth heating cylinder heater 30H4 is not provided with the cooling unit is that a tip of the heating cylinder 19 is exposed and is relatively easily cooled.
The operation of the heating cylinder heater 30 according to the present illustrative embodiment will be described. When starting operation in the injection molding machine 1 (see
The heating cylinder 19 generates heat by a shearing force acting on the injection material at the time of rotation of the screw 20. When a molding cycle is repeated, the heat generation may cause the heating cylinder 19 to exceed the target temperature depending on the position. The control device 4 drives the opening-closing unit 42 (see
In the heating cylinder heater 30 according to the present illustrative embodiment, the cover 32 is provided with the opening portions 39 and 40, and the opening-closing unit 42 is provided for the opening portion 40 at the upper part, so that the heating cylinder 19 can be rapidly cooled. Therefore, for example, it is possible to rapidly cool the heating cylinder 19 even in an operation of changing a type of the injection material, that is, changing a resin, changing a color, or the like, and thus the efficiency is good. Further, the cooling can be performed efficiently by utilizing convection of air, so that energy saving is achieved.
The present illustrative embodiment can be variously modified.
Various other modifications can be made for the present illustrative embodiment. For example, in the first illustrative embodiment, the second heating cylinder heater 30H2 and the third heating cylinder heater 30H3 are described such that the opening portions 39 and 39 at the lower part of the covers 32 and 32 are always opened. However, an opening-closing unit may be provided in these opening portions 39 and 39. When cooling is required, the opening-closing unit may be driven to open the opening portions 39 and 39.
Other modifications are also possible. The heating cylinder heater 30 is described to include the first to fourth heating cylinder heaters 30H1, 30H2, . . . . Alternatively, the number of the heating cylinder heaters may be three or less or five or more. In the present illustrative embodiment, it has been described that the opening portions 39 and 40 are not opened in the first heating cylinder heater 30H1 and the fourth heating cylinder heater 30H4. However, the opening portions 39 and 40 may be formed in the first heating cylinder heater 30H1 and the fourth heating cylinder heater 30H4, and the opening-closing unit 42 of the opening portion 40 may be provided thereto.
Although the invention made by the present inventor is specifically described based on the illustrative embodiments, it is needless to say that the present invention is not limited to the illustrative embodiments described above, and various modifications can be made without departing from the scope of the invention. A plurality of examples described above may be implemented in combination as appropriate.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2022-084919 | May 2022 | JP | national |
