JPH04115620U - Injection molding machine nozzle drip prevention device - Google Patents

Abstract

(57) [Summary] [Objective] To provide a nozzle drip prevention device for an injection molding machine that can prevent the phenomenon of nasal drip from a molten resin nozzle. [Structure] A resin material is supplied and plasticized into a heating cylinder 4 that is provided to move forward and backward with respect to a mold 10, and the plasticized resin material is passed through a screw 3 in the heating cylinder 4.
Therefore, in an injection molding machine that injects from an open nozzle 2 into a mold 10, the nozzle 2 is moved forward and backward, and in a direction intersecting the axis of the nozzle 2, with respect to the nozzle 2 at a nozzle retracted position spaced apart from the mold 10 by a predetermined distance. A nozzle hole closing member 23 that is movably provided and can be brought into close contact with the nozzle 2 is provided at the front of the nozzle 2.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention relates to a nozzle drip prevention device for an injection molding machine.

0002

[Conventional technology]

Conventionally, as shown in Fig. 4, a hopper 1 was installed at the root end and an injection nozzle (hereinafter simply referred to as A screw (referred to as a nozzle) 2 is installed inside the nozzle so that it can rotate freely and move back and forth in the axial direction. A heating cylinder 4, each equipped with a heating cylinder 3, is provided on the main body 5 so as to be able to move forward and backward. A fixed plate 6 and an end plate 7 are provided at a distance in front of the nozzle 2. In between, a movable platen 9 is supported by tie rods 8 and movable by a mold clamping cylinder. A hopper 1 is placed in a mold 10 which is attached to the movable platen 9 and the fixed platen 6. An injection process in which the resin supplied into the heating cylinder 4 is injected from the nozzle 2 to perform molding. A molding machine is known. This injection molding machine aims to uniformly melt the resin and produces high quality In order to obtain injection molded products, a nozzle with a built-in shut-off valve mechanism is installed in the injection device. The resin is plasticized while applying pressure (back pressure) inside the heating cylinder 4. There is a method. The shutoff valve mechanism includes a lever that rotates around a fulcrum. - by rotating it via a rod that reciprocates with a hydraulic cylinder etc. The needle valve is moved in its axial direction to open and close the hole at the tip of the nozzle. and Injection molding machines for thermosetting resins have a shutoff valve in the nozzle. If a mechanism is provided, resin may accumulate in this nozzle, remain, and harden. Therefore, we cannot adopt the above-mentioned shut-off valve mechanism, and instead use an open nozzle. We are hiring. In addition, in the figure, 3a is an injection cylinder.

0003

[Problem that the idea aims to solve]

However, in the injection molding machine for thermosetting resin, as mentioned above, the open nozzle This injection molding machine always has a nozzle during one cycle of the process. There is a sliding backward movement, and due to the stability of measuring the amount of resin material, it is difficult to apply the spine to the screw. Since pressure is also required, resin may drip (leak) from the nozzle when the nozzle retreats. It is easy to cause In particular, in a thermosetting parting injection molding machine, the inside of the heating cylinder 4 is In order to avoid resin accumulation, a metering operation is performed just before injection (at this time, the nozzle Zulu is retreating. ), the nasal drip phenomenon is more likely to occur.

0004 The present invention was developed in view of the above circumstances, and is designed to prevent nasal drip from the molten resin nozzle. Our aim is to provide an injection molding machine nozzle droop prevention device that can prevent target

[0005]

[Means to solve the problem]

The present invention has the following configuration to achieve the above object. That is, gold The resin material is supplied and plasticized into a heating cylinder that can move forward and backward relative to the mold. Then, the plasticized resin material is introduced into a screw provided in the heating cylinder. Molding is performed by injecting into the mold from the open nozzle at the tip of the heating cylinder. In an injection molding machine, a nozzle in a retracted position separated from the mold by a predetermined distance. at the tip of the nozzle, movable forward and backward in the axial direction of the nozzle, and in the axial direction of the nozzle. A nozzle that is movable in a direction crossing the nozzle and that can be brought into close contact with the nozzle. The structure includes a hole closing member.

[0006]

[Effect]

According to the above configuration, when performing injection molding, the nozzle in the retracted position is Then, the nozzle hole closing member approaches the nozzle tip and closes the nozzle hole. In this state, the resin material is supplied to the inside of the heating cylinder and plasticized. When the heating is completed, the nozzle hole blocking member is retracted from the nozzle, and then the heating cylinder is turned off. The nozzle moves forward and touches the mold in the closed state. Next, the screen The mold moves forward, and the nozzle injects molten resin material into a cavity within the mold. child The resin material is processed with the nozzle hole closed by the nozzle hole closing member as shown in the figure. Since it is plasticized in the heat cylinder, the wood is melted and transferred to the nozzle side. Even if the nozzle is an open nozzle, the greasy material leaks from the open nozzle. The so-called nasal drip phenomenon is reliably prevented.

[0007]

【Example】

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. Please note that this implementation In the example, the same parts as in the conventional example are given the same reference numerals, and detailed explanation thereof will be omitted. In FIG. 3, 11 is a main body of an injection molding machine for thermosetting resin, and on this main body 11, A base 12 is attached to the base 12 with a plurality of bolts. The base 12 has heating The support member 14 to which the cylinder 4 is connected is connected to the front and rear (left side in FIG. 3) via the guide member 14. right) and is movably supported by the frame attached to the base 12 and the support member 14. By driving the feed cylinder 13, the heating cylinder 4 approaches and moves away from the fixed plate 6. It is made to be.

[0008] A hook-shaped bracket 15 is attached to the end surface of the main body 11 on the fixed platen 6 side. A pair of guide tubes 16, 16 are provided on the support plate 15a of the bracket 15 as shown in FIG. As shown, they are spaced apart from each other, pass through the support plate 15a, and are fixedly attached vertically. ing. Additionally, a vertical drive cylinder (air cylinder) is mounted on the support plate 15a of the bracket 15. A cylinder) 18 is located between the pair of guide cylinders 16, 16, and A stone rod 18a passes upward through the connecting plate 17 and is attached in a hanging manner. . Rods 19, 19 are vertically slidable in the pair of guide tubes 16, 16, respectively. It has been inserted. The upper ends of these rods 19, 19 are supported above the support plate 15a. They are connected by a vertically movable plate 20 provided parallel to the plate 15a. a pair of rods The lower ends of 19 and 19 are connected by a connecting plate 17. The lower surface of this vertically moving plate 20 A mounting member 21 is fixed to the mounting member 21, and the vertical drive cylinder is attached to the mounting member 21. Eighteen piston rods 18a are attached. Therefore, the vertical drive cylinder 1 The vertical movement plate 20 is configured to move up and down by the expansion and contraction operation of 8.

[0009] The vertical movement plate 20 includes a longitudinal drive cylinder (air cylinder) 23 and a heating cylinder. 4, and its piston rod is positioned on the side of the nozzle 2. installed. The tip of the piston rod of the longitudinal drive cylinder 23 (nozzle hole A spherical recess 24 that matches the tip end surface of the nozzle 2 is formed at the center of the end surface of the closing member). has been completed. Additionally, there is a hook-shaped structure on the upper surface of the piston rod of the longitudinal drive cylinder 23. A claw 22 is attached. The tip of this claw 22 is directed downward. on the other hand , the position below the retraction limit of the nozzle 2 is at the lower limit position of the vertical drive cylinder 18. Attachment having a rotary tool 25 whose rotation axis coincides with the axis of the longitudinal drive cylinder 23. The resin removal tool is attached to a fixed part of the bracket 15 or the main body 11, etc. Ru. The tip of this rotary tool 25 is the tip of the piston rod of the longitudinal drive cylinder 23. The convex blade portion 26 is formed into a spherical surface with approximately the same curvature as the concave portion 24 of the blade. In addition , 27 in FIGS. 1 and 3 is a rib for reinforcing the bracket 15, and in FIG. , 3b is a rotation drive device for a screw provided in the heating cylinder 4.

0010 However, when performing injection molding, the mold is in a closed or clamped state. When the nozzle is in the retracted position with a predetermined distance from the mold, it is in a contracted state. When the vertical drive cylinder 18 is extended, the axis of the front and rear drive cylinder 23 is heated. It is located on the same axis as the axis of the cylinder 4. After this, the longitudinal drive cylinder 23 When the piston rod is extended, the recess 24 on the end surface of the piston rod is brought into close contact with the tip of the nozzle 2. to close the nozzle hole. Next, the screw 3 inside the heating cylinder 4 rotates and A resin material is supplied into the heat cylinder 4, and this resin material is heated while being kneaded and melted. Molten wood transferred to the nozzle 2 side of the cylinder 4 and transferred to the tip side of the screw 3 The screw 3 is pushed back by the pressure of the oil, and the retreat distance of the pushed back screw 3 When the molten resin is measured and the screw 3 reaches the set position, the screw 3 stops rotating. Here, the longitudinal drive cylinder 23 and the vertical drive cylinder 18 is sequentially contracted, and the axis of the longitudinal drive cylinder 23 is aligned with the axis of the rotary tool 25. position, and the piston rod (nozzle hole closing member) of the longitudinal drive cylinder 23 is the nozzle. 2 is in a retracted position from the front of heating cylinder 4 to a position that does not interfere with the forward movement of heating cylinder 4. . Next, the feed cylinder 13 is extended, the heating cylinder 4 moves forward, and the mold is closed. The nozzle touches the injection resin inlet of the mold. After this, injection cylinder 3 a is extended, the screw 3 moves forward, and the nozzle 2 pours the melt into the cavity in the mold. Molten resin is injected.

[0011] Next, while the molded product injection molded in the mold is being cooled and solidified, the feed series is The cylinder 13 contracts and the heating cylinder 4 moves away from the stationary plate 6, bringing the nozzle to the retracted position. is reached and stopped. In the above, the front and rear drive cylinder 23 is contracted and the nozzle is 2, the residual pressure of the molten resin in the heating cylinder 4 causes the nozzle to move away from the tip of the nozzle 2. A small amount of the molten resin may come out and adhere to the outside of the nozzle 2. When the vertical drive cylinder 18 descends, the oil is attached to the front and rear drive cylinder 23. It is scraped off by the claw 22. In addition, the axis of the front and rear drive cylinder 23 is a rotary tool. 25, the front and rear cylinders 23 extend and rotate. When the concave surface of the concave portion 24 of the front and rear cylinders 23 is brought into contact with the rotary tool 25, the front The resin attached to the recess 24 of the piston rod of the rear drive cylinder 23 is a rotary tool. 25, it is easily removed.

0012 According to this embodiment, when the nozzle 2 is in the retracted position, the front and rear shafts are attached to the tip of the nozzle 2. Close the recess 24 of the piston rod (nozzle hole closing member) of the cylinder 23 to open the nozzle. With the holes closed, a resin material is supplied into the heating cylinder 4, and the resin material is heated. Since it can be transferred to the nozzle side while being kneaded and melted, nozzle 2 is shut off. Although it is an open nozzle without a valve mechanism, the melt from the nozzle 2 during plasticization is There is no leakage of molten resin, and the phenomenon of nasal drip can be reliably prevented.

[0013]

[Effect of the idea]

According to the present invention, the resin is placed inside the heating cylinder that is movable forward and backward with respect to the mold. A material is supplied and plasticized, and the plasticized resin material is placed in the heating cylinder. The mold is removed from the open nozzle at the tip of the heating cylinder using a screw. In an injection molding machine that performs molding by injecting into the mold, the At the tip of the nozzle in the nozzle retreat position, there is a is provided so as to be movable in a direction crossing the axis of the nozzle, and close to the nozzle. Since a nozzle hole closing member that can be touched is provided, the nozzle can be closed in the retracted position of the nozzle. The nozzle hole closing member can be brought into close contact with the tip of the nozzle. The resin material is supplied into the heating cylinder while the cylinder is closed by the closing member. The material can be transferred to the nozzle side while being kneaded and melted. To reliably prevent the phenomenon of nasal drip from this nozzle, even though it is a flat nozzle. It is particularly suitable as a nozzle drip prevention device for injection molding machines for thermosetting resins. Ru.

[Brief explanation of drawings]

FIG. 1 is a side view of essential parts showing an embodiment of the present invention.

FIG. 2 is a rear view of essential parts showing an embodiment of the present invention.

FIG. 3 is a side view of an injection molding machine showing an embodiment of the present invention.

FIG. 4 is a schematic side view of a conventional injection molding machine.

[Explanation of symbols]

1 Hopper 2 Injection nozzle (open nozzle) 3 Screw 4 Heating cylinder 10 Mold 18 Upper and lower cylinder (air cylinder) 22 Claw 23 Front and rear cylinder (air cylinder) (nozzle hole closing member) 24 Recess 25 Rotary tool

Claims (1)

[Scope of utility model registration request] 1. A resin material is supplied and plasticized into a heating cylinder provided to move forward and backward with respect to a mold, and the plasticized resin material is transferred by a screw provided in the heating cylinder. In an injection molding machine that performs molding by injecting into a mold from an open nozzle at the tip of the heating cylinder, the nozzle is moved forward and backward in the axial direction relative to the nozzle at a retracted position spaced apart from the mold by a predetermined distance. A nozzle nasal drip prevention device for an injection molding machine, comprising a nozzle hole closing member that is freely movable in a direction intersecting the axis of the nozzle and that can be brought into close contact with the nozzle.