JP3343006B2 - Melt injection equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a melt injection apparatus, and more particularly, to a melt injection apparatus for injecting pellets such as plastic into molten plastic (hereinafter referred to as "melt").

[0002]

2. Description of the Related Art A conventional melt injection device of a plastic injection molding machine uses a screw mechanism as shown in FIG. In this mechanism, plastic pellets 51 (hereinafter, pellets) stored in a hopper 50 are supplied into a cylinder 52. The supplied pellets are screw 53
The melt is generated by the frictional heat generated by the rotation of the cylinder and the inner surface of the cylinder and the heat from the heater 54 on the outer surface of the cylinder to generate a melt, and the melt is transferred to the tip of the cylinder.

As shown in FIG. 6, the screw 53 retreats in the direction A due to the pressure of the melt supplied to the tip of the cylinder due to the rotation of the screw, and a predetermined amount of melt 55 is accumulated at the tip of the cylinder. Stop B
By extruding in the direction, the melt is injected into an external mold (not shown).

[0004]

In the above-described conventional screw-type injection device, the function of melting the pellets to generate a melt and the function of injecting the melt are performed using the same cylinder 52. . In order to melt the pellets by friction heat or the like, a predetermined area of the rotating surface of the screw 53 and the inner wall surface of the cylinder 52 facing each other is required. Therefore, when the diameter of the cylinder 52 is reduced, it is necessary to increase the overall length, and when reducing the overall length, it is necessary to increase the diameter. On the other hand, when the melt is injected by the screw 53, a predetermined pressure is applied per unit area. Therefore, when the diameter of the cylinder 52 is large, a large force is required to inject the melt. For this reason, increasing the diameter instead of shortening the overall length of the cylinder 52 is limited.

[0005] For this reason, the screw diameter cannot be increased due to the relationship between the high pressure during melt injection and the outflow viscosity resistance, and a surface area for supplying a necessary amount of heat until the room temperature pellet is melted is generally required. The screw will need 15-20 times longer than its diameter,
There was a drawback that the device became longer.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art and to provide a melt injection device which can be shortened.

[0007]

To achieve the above object, a melt injection apparatus according to the present invention has an injection chamber having an injection hole for injecting a melt to the outside, and is housed in the injection chamber. An injection piston movable in the injection chamber for injecting the melt from the injection hole, and communicating with the injection chamber via a passage provided independently of the injection chamber and through which the melt is transferred. Melting chamber to be, rotatably disposed in the melting chamber, a melting rotator that melts the pellets contained between the peripheral body and the inner wall of the melting chamber to produce a melt, A melt extruding member which is fitted as closely as possible to the peripheral body of the rotating body for melting and is arranged so as to be movable in the rotation axis direction of the rotating body for melting. I do.

Preferably, the melting chamber has a conical conical portion in a lower portion, and the melting rotating body has a conical conical portion in a lower portion. A space sandwiched between the conical portion and the conical portion of the melting rotary member is formed to be narrower downward.

Further, a screw is provided at the bottom of the melting rotary member.

[0010] Further, there is provided pressing means for pressing the pellets contained between the melting chamber and the rotating body for melting downward.

[0012] A preheater is provided inside the peripheral body of the rotating body for melting.

Further, a preheater is provided outside a passage communicating the injection chamber and the welding chamber.

[0013] In the melt injection apparatus according to the present invention, the injection chamber is provided independently of the melting chamber and communicates with the melting chamber through a passage through which the melt is transferred. Since it has only the function of generating, there is no problem even if the structure has a large diameter and a short overall length. The function of injecting the melt is performed by an injection chamber provided independently of the injection chamber.

The pellets housed in the space formed by the melting rotator and the melting chamber are melted by the frictional heat generated by the rotation of the melting rotator to produce a melt. The melt mainly adheres to the peripheral body of the rotating body for melting. By pressing the melt extruding member downward in the direction of the rotation axis, the melt adhered to the peripheral body of the rotating body for melting is scraped off from the peripheral body and transferred to the injection chamber via the passage.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a melt injection device according to the present invention will be described below with reference to the drawings.

First, a first embodiment of the present invention will be described with reference to FIG. In FIG. 1, an injection chamber 3 having an injection hole 2 for injecting the melt 1 to the outside is provided at the bottom of the melt injection device, and the melt 1 is injected from the injection hole 2 into the injection chamber. The injection piston 4 is provided so as to be movable within the injection chamber 3.

Above the injection chamber 3, a cylindrical melting chamber 5 independent of the injection chamber 3 is provided. The melting chamber 5 is provided at the bottom through a passage 6 through which the melt 1 is transferred. It communicates with the injection chamber 3.

The melting chamber 5 has an upper large cylindrical portion and a lower small cylindrical portion. The large cylindrical portion and the small cylindrical portion are connected by a conical large conical portion 5a. Is a conical small conical part 5b
Connected by Small cylindrical part and small conical part 5b
A heater (preheater) 9 for melting the pellets remaining mixed in the melt 1 is wound around the outer periphery of the melt 1.

In the melting chamber 5, a cylindrical rotating body 7 for melting is rotatably arranged. The melting rotator 7 is supported so as to rotate around a rotation axis 8.
The rotating shaft 8 is driven to rotate by rotating means such as a motor (not shown). The rotating body 7 for fusion is disposed so that the direction of the rotation axis is the direction of gravity.

A conical portion 7a is formed below the rotating body 7 for melting. Conical part 7a and large conical part 5a
The space sandwiched between is narrowed downward. A pellet 10 is stored in a space formed by the rotating body 7 for melting and the chamber 5 for melting. Rotating body for melting 7
Although no special irregularities such as flights are formed on the peripheral body of, appropriate irregularities may be formed in order to apply a large frictional force to the pellet 10.

A melt extruding member 11 is fitted to the peripheral body of the rotating body 7 for melting so as to be slidable in the direction of the rotation axis 8 of the rotating body for melting as closely as possible. The melt extruding member 11 can press the upper flange portion in the direction of the rotating shaft 8.

Next, the operation of this embodiment will be described.

The pellets 10 accommodated in the space formed by the rotating body 7 for melting and the chamber 5 for melting are melted by frictional heat generated by the rotation of the rotating body 7 for melting and melted.
Is generated, and the melt mainly adheres to the peripheral body of the rotating body 7 for melting. By pressing the upper flange portion of the melt extruding member 11 in the direction of the rotating shaft 8, the melting rotary member 7 is formed.
The melt 1 attached to the peripheral body is scraped off from the peripheral body and the melt 1 is transferred to a space sandwiched between the conical portion 7a and the large conical portion 5a. Since the space between the conical portion 7a and the large conical portion 5a is formed narrower downward,
The melt 1 receives a higher pressure as it moves downward, and gas such as air mixed in the melt 1 is released. further,
The melt 1 is heated by the heater 9, and the pellets 10 remaining mixed in the melt 1 are dissolved. Finally, the melt 1 is transferred to the injection chamber 3 through the passage 6. The melt 1 transferred to the injection chamber 3 is injected from the injection hole 2 by moving the injection piston 4 in the direction C in the injection chamber 3.

As described above, according to the configuration of this embodiment, the melting chamber 5 and the injection chamber 3 are provided independently and communicated with each other through the passage 6, so that the melting chamber 5 and the injection chamber 3 are connected to each other. The melting chamber and the injection function can be shared and assigned to the melting chamber 3, respectively. As a result, the diameter of the melting chamber 5 can be increased and the overall length can be shortened. Will be possible.

Further, since the melting function and the injection function are shared, it is possible to provide a melt-injection apparatus capable of exchanging materials in a short time without causing useless materials when switching the materials.

Further, a melting rotator 7 is rotatably provided in the melting chamber 5, and the melt extruding member 11 is slidable in the direction of the rotation shaft 8 as densely as possible on the peripheral body of the rotator 7. Since the melt is pushed outside, the melt push-out member 11 is pressed in the direction of the rotating shaft 8 to scrape off the melt 1 attached to the peripheral body of the rotating body 7 for melting, and transfer the melt 1 to the injection chamber 3 via the passage 6. It becomes possible to do. As a result, the melt injection device can be formed with a simple configuration. It is possible to provide a melt-injection apparatus capable of exchanging materials in a short time without causing useless materials at the time of material switching.

Next, a second embodiment of the present invention will be described with reference to FIG. In the present embodiment, a screw 20 is provided at the bottom end of the rotating body 7 for melting.

By providing the screw 20, the melt 1 can be kneaded more reliably in the space sandwiched between the conical portion 7a and the large conical portion 5a. Can be transported within.

Next, a third embodiment of the present invention will be described with reference to FIG. In the present embodiment, a cylindrical pressing ring 21 for pressing the pellets 10 accommodated between the melting chamber 5 and the rotating body 7 downward from the upper surface is provided. The pressing ring 21 is arranged with a slight gap between the outer surface of the peripheral body of the melt extruding member 11 and the inner surface of the partial melting chamber 5.

By pressing the pressing ring 21 downward by an actuator (not shown), the pellet 10 can be effectively supplied to the peripheral body of the rotating body 7 for melting. Also, instead of pressing the pressing ring 21 with an actuator, the pressing ring 21 is simply pressed into the pellet 1.
The pressing force can be generated by placing the pellet pressing ring 12 under its own weight on the upper surface.

Next, a fourth embodiment of the present invention will be described with reference to FIG. In the present embodiment, a heater (preheater) 22 is wound inside the peripheral body of the rotating body 7 for melting.

By heating the pellets 10 from the inside of the rotator 7 by the heater 22, the pellets 1 accommodated between the melting chamber 5 and the rotator 7 are melted.
0 can be shortened.

In the embodiment of the present invention described above, the heater 9 may be divided into several parts, or another heater may be provided outside the melting chamber 5 or outside the injection chamber 3. . The preheater for preheating the pellets is not limited to the heater type, but may be a hot air type, for example. Further, the melting chamber 5 may be provided with a pellet discharge hole or the like for material switching to switch the material.

[0034]

As described above, according to the structure of the present invention, the melting chamber and the injection chamber are independently provided and communicated with each other by the passage. It becomes possible to share the melting function and the injection function respectively, and as a result,
The diameter of the melting chamber can be made large and the total length can be made short, which makes it possible to shorten the length of the melt injection device. It is possible to provide a melt-injection apparatus capable of exchanging materials in a short time without causing useless materials at the time of material switching.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing the overall configuration of a first embodiment of a melt injection device according to the present invention.

FIG. 2 is a longitudinal sectional view showing the overall configuration of a second embodiment of the melt injection device according to the present invention.

FIG. 3 is a longitudinal sectional view showing the entire configuration of a third embodiment of a melt injection device according to the present invention.

FIG. 4 is a longitudinal sectional view showing the entire configuration of a fourth embodiment of a melt injection device according to the present invention.

FIG. 5 is a cross-sectional view showing the overall configuration of a conventional melt injection device.

FIG. 6 is a sectional view for explaining the operation of a conventional melt injection device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Melt 2 Injection hole 3 Injection chamber 4 Injection piston 5 Melting chamber 5a Large cone part 5b Small cone part 6 Passage 7 Melting rotating body 7a Conical part 8 Rotating shaft 9 Heater (preheater) 10 Pellet 11 Melt pushing member Reference Signs List 20 screw 21 pressing ring 22 heater (preheater)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-316823 (JP, A) JP-A-9-29797 (JP, A) JP-A-9-29796 (JP, A) 82768 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B29C 45 / 53,45 / 54,45 / 74 B29B 7/30-7/72

Claims (6)

(57) [Claims] An injection chamber having an injection hole for injecting a melt, and an injection chamber movable in the injection chamber for injecting a melt contained in the injection chamber from the injection hole. A piston, a melting chamber that is provided independently of the injection chamber and communicates with the injection chamber through a passage through which a melt is transferred, and is rotatably disposed in the melting chamber, and has a peripheral body portion and A rotating body for melting which melts the pellets contained between the inner wall of the chamber for melting and generates a melt; and a rotation of the rotating body for melting which is fitted as closely as possible to the peripheral body of the rotating body for melting. A melt extruding member disposed so as to be movable in the axial direction. 2. The melting chamber has a conical conical portion in a lower portion, and the melting rotary body has a conical conical portion in a lower portion. 2. The melt injection device according to claim 1, wherein a space sandwiched between the conical portion of the melting rotary body is formed to be narrower downward. 3. 3. The melt injection device according to claim 1, wherein a screw is provided at a bottom portion of the melting rotary body. 4. The melt-injection apparatus according to claim 1, further comprising pressing means for pressing the pellets contained between the melting chamber and the rotating body for melting downward. 5. The melt injection device according to claim 1, wherein a preheater is provided inside a peripheral body of the rotating body for melting. 6. The melt injection apparatus according to claim 1, wherein a preheater is provided outside a passage connecting the injection chamber and the welding chamber.