JPH0560824U - Check valve for thermosetting resin - Google Patents

Abstract

(57) [Abstract] [Purpose] A backflow prevention valve for thermosetting resin that can prevent the backflow of molten resin and keep the injection amount constant, and can easily clean the inside of the heating cylinder and the vicinity of the ring. A check valve for thermosetting resin is provided. A screw head 1 having a thin shaft portion 14 and a tip portion 15 with a wear plate 16 at the tip of a screw body portion 12 fitted in an inner hole of a heating cylinder 31 of an injection device 30.
3 is attached to the heating cylinder while a ring valve 20 composed of divided pieces 21 and 22 bisected in the cylinder direction is formed on the thin shaft part while forming a resin flow path 19 between the thin shaft part and the thin shaft part of the screw head. Fit in the inner cylinder of.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 This invention relates to a check valve for thermosetting resin.

[0002]

[Prior Art]

 As shown in Fig. 4, the screw of the conventional injection device for injection molding thermosetting resin such as phenol resin is a so-called one-piece screw in which the screw tip is tapered from the screw body. Used. Reference numeral 40 is a screw, 41 is a screw main body, and 42 is a screw tip portion.

However, since this screw 40 is not provided with a backflow prevention valve, there is a problem of backflow of the molten resin at the time of ejection, and the injection amount of the resin varies, which causes a problem in quality control of the product. ..

Therefore, as shown in FIG. 5, when a check valve which has been conventionally used for a thermoplastic resin is applied to a thermosetting resin, a check valve is provided between the screw head 52 and the ring valve 54 and a wear plate 55. Occasionally, resin stagnates with the ring valve 54. In addition, the passing area of the resin is small, which may cause exothermic curing of the molten resin. In such a structure, once the resin has hardened, the screw head is removed and the hardened resin is hit and broken, which requires a lot of time and effort for the removal of the resin. It was difficult to completely remove the resin cured on the shaft.

[0005]

[Problems to be solved by the device]

 The present invention was proposed to solve the above-mentioned problems, and is a check valve for thermosetting resin that can prevent the back flow of molten resin and keep the injection amount constant. An object of the present invention is to provide a check valve for thermosetting resin, which can easily clean the inside of the cylinder and the vicinity of the ring.

[0006]

[Means for Solving the Problems]

 That is, according to this invention, a screw head having a thin shaft portion and a tip portion is attached to the tip of the screw main body fitted in the inner hole of the heating cylinder of the injection device via a wear plate, and the thin shaft portion is attached to the screw head. A thermosetting resin, characterized in that a ring valve consisting of a split piece divided into two in the cylinder direction is fitted in the inner hole of the heating cylinder while forming a resin flow path between the screw shaft and the thin shaft portion of the screw head. Related to check valve for resin.

[0007]

【Example】

 Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a cutaway vertical sectional view showing an example of the check valve of the present invention, FIG. 2 is a perspective view showing an example of a ring valve used in the check valve of the present invention, and FIG. 3 is a division of the ring valve of FIG. It is a perspective view showing the state where it did.

FIG. 1 shows an example of the check valve 10 for thermosetting resin of the present invention. Reference numeral 11 in the drawing denotes a screw fitted in the inner hole of the heating cylinder 31 in the injection device 30, and the screw head 13 is fixed to the tip of the main body 12 via the wear plate 16.

The screw head 13 has a thin shaft portion 14 and a tip portion 15 formed at the tip of the thin shaft portion, and is attached to the screw body portion 12 by screwing (not shown). There is.

A ring valve 20 is fitted to the thin shaft portion 14 while forming a resin flow path 19 between the ring valve 20 and the thin shaft portion 14. The ring valve 20 is a cylindrical valve member that slides in the heating cylinder of the injection device 30 in order to prevent the molten resin from flowing backward during injection, and the split pieces 21 and 22 are divided into two in the cylinder direction. 2 and 3, a concave portion 25 is formed on the dividing surface 23 of the dividing piece 21 of the ring valve 20 and a concave portion 25 is formed on the dividing surface 24 of the corresponding dividing piece 22. The convex portion 26 to be attached is formed, and is configured to be fitted and removed.

Thus, the screw cleaning method of the conventional thermosetting resin injection device is used to project the screw head 13 and the ring valve 20 from the tip of the heating cylinder, and then the ring valve 20 is divided into inner surfaces. The thin shaft portion 14 of the screw head 13 can be reliably cleaned.

In this embodiment, tapered surfaces 29 are formed on the front and rear ends 27 and 28 of the split pieces 21, 22 of the ring valve 20. On the other hand, as shown in FIG. 1, the resin flow path is provided by providing the tip end portion 15 of the screw head 13 and the wear plate 16 with tapered surfaces 17 and 18 that come into contact with the tapered surface 29 of the ring valve 20. 19 can be formed widely and smoothly, and prevents molten resin from staying and being cured by heat.

[0013]

[Effect of the device]

 As shown and described above, according to the ring valve of the thermosetting resin injection device of the present invention, the tip of the screw main body fitted in the inner hole of the heating cylinder of the injection device is inserted through the wafer plate. A screw head having a thin shaft portion and a tip portion is attached, and at the same time, a ring valve consisting of a split piece divided into two parts in the cylinder direction is provided on the thin shaft portion, and a resin flow path is provided between the thin shaft portion and the thin shaft portion of the screw head. Since it is fitted into the inner cylinder of the heating cylinder while being formed, it not only prevents the backflow of molten resin but also maintains a constant injection amount and improves the weight accuracy of the molded product, it also cleans the inside of the heating cylinder and the vicinity of the ring. Can be performed easily and work efficiency can be significantly improved.

[Brief description of drawings]

FIG. 1 is a cutaway longitudinal sectional view showing an example of a check valve for thermosetting resin of the present invention.

FIG. 2 is a perspective view showing an example of a ring valve used in the check valve for thermosetting resin of the present invention.

FIG. 3 is a perspective view showing a state where the ring valve of FIG. 2 is divided.

FIG. 4 is a side view showing an example of a screw of a general thermosetting resin injection device.

FIG. 5 is a side view in which a main part of another example is cut away.

[Explanation of symbols]

 10 Backflow Prevention Valve 11 Screw 12 Screw Main Body 13 Screw Head 14 Thin Shaft Part 15 Tip Part 16 Wear Plate 19 Resin Flow Path 20 Ring Valve 21 Split Piece 22 Split Piece

Claims (1)

[Scope of utility model registration request] 1. A screw head having a thin shaft portion and a tip end portion is attached to a tip end of a screw main body portion fitted in an inner hole of a heating cylinder of an injection device via a wear plate, and
A ring valve, which is a split piece divided into two in the cylinder direction, is fitted to the thin shaft portion in the inner hole of the heating cylinder while forming a resin flow path between the thin shaft portion and the thin shaft portion of the screw head. Check valve for thermosetting resin.