JPH0737851Y2 - Injection molding machine feed device - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a feed device of an injection molding machine that automates the dropping of raw materials.

[0002]

2. Description of the Related Art An injection molding machine is of a type provided with a feed device of an injection molding machine for supplying or dropping a raw material by a feed screw. This type of machine supplies a desired amount of raw material by driving the feed screw. Drop from the hopper through the feed cylinder to the raw material drop port. The raw material used in such an injection molding machine is generally formed into spherical or polyhedral pellets having a diameter of about 3 mm to 5 mm, and chips or fine powder are generated during the pellet manufacturing process.

Particularly, fine powder of raw material (hereinafter referred to as fine powder) easily adheres to the wall surface near the raw material dropping port and the valley of the main screw, and the fine powder adhered is separated by vibration generated during the operation of the injection molding machine, so-called burning. This may cause a defect, or fine powder may enter between the main screw crest and the heating cylinder, causing an extremely loud squeal in the operating injection molding machine.

In order to eliminate the above-mentioned inconvenience, as shown in FIGS. 5 and 6, the bag filter 18 is provided immediately before the raw material dropping port 17.
Therefore, only the fine powder is collected during the supply of the raw material. However, with the passage of time, the bag filter 18 will be clogged with fine powder, and it will take time and effort to replace and clean the bag filter 18.

Therefore, after the pellet and the fine powder are separated by using a sieve in advance, only the pelletized raw material is supplied to the injection molding machine. In addition, in FIG. 5 and FIG.
Reference numeral 19 is a feed cylinder, and 20 is a feed screw.

[0006]

In other words, the work of separating the fine powder and the pellets is carried out independently before the raw material is supplied to the raw material of the injection molding machine, and the work is omitted to eliminate the above-mentioned inconvenience. I can't. This makes it difficult to simplify the molding work and improve workability.

Therefore, the present invention has an object to provide a feed device of an injection molding machine for separating fine powder and pellets before the raw material is fed from the feed cylinder to the main screw by the feed screw.

[0008]

In order to achieve the above object, the present invention provides through holes having a diameter smaller than the pellet diameter at a plurality of locations from the bottom of the feed cylinder of the feed cylinder toward the outside of the feed cylinder. It is equipped with the configuration.

Further, the through hole is formed in a cross-sectional shape that tapers from the bottom side of the raw material supply path toward the outside of the feed cylinder.

[0010]

Since the present invention is configured as described above, the fine powder smaller than the pellet diameter is discharged to the outside of the feed cylinder through the through hole, and only the raw material from which the fine powder has been removed is fed along the raw material supply path by the feed screw. Supplied to the main screw.

When the through-hole has a cross-sectional shape that expands in a taper shape from the bottom side of the raw material supply passage toward the outside of the feed cylinder, the fine powder inserted through the opening of the through-hole on the raw material supply passage side has the same shape. Is reliably discharged to the outside of the feed cylinder.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. In FIG. 1 and FIG. 2, 1 indicates a main part of a feed device of an injection molding machine, 2 indicates a feed cylinder, and 3 indicates a feed screw. The rotation speed of the feed screw 3 and the rotation speed of the main screw (not shown) can be independently set according to the molding conditions.

The feed screw 3 is for supplying the pellet-shaped raw material stored in the hopper 4 to the main screw, and the raw material passes through the raw material supply path 5 of the feed cylinder 2, that is, the inner hole by the operation of the feed screw 3. Then, it is guided from the raw material dropping port 6 to the heating cylinder 7 and the main screw. The raw material is granulated into spherical pellets in this embodiment, and the pellet spherical diameter is set within the range of 3 mm to 5 mm.

A plurality of through holes 8 are formed at the bottom of the raw material supply passage 5, and the through holes 8 are arranged along the axis of the feed screw 3. The through hole 8 is formed with a diameter smaller than the diameter of the pellet. Further, the cross-sectional shape of the through hole 8 is formed into a trapezoid, and the upper base diameter of this trapezoid is set smaller than the pellet diameter, and moreover, it is tapered from the upper bottom side to the outside of the feed cylinder 2 (lower bottom side). Has been expanded to.

In this embodiment, the through hole 8 has an upper bottom diameter of 2 mm.
The bottom diameter of the through hole 8 is set to 6 mm. The distance between the upper bottom and the lower bottom is set to be larger than the maximum pellet spherical diameter (5 mm in this embodiment-see FIG. 3). Thus, while the raw material supply path 5 is being conveyed by the feed screw 3 toward the raw material dropping port 6, fine powder having a diameter smaller than 2 mm is discharged from the through hole 8 to the outside of the feed cylinder 2. The raw material discharged from the through holes 8 is accumulated and collected in the fine powder collecting box indicated by 9.

Further, in FIG. 1, 10 and 10 are feed screws 3
Bearings, 11 is a flange, and 12 is a bolt. In this embodiment, the through hole 8 is formed in the screen indicated by 13 in FIGS.
Is detachably attached to the raw material supply path 5 of the feed cylinder 2 by the bolts 14 shown in FIG. Further, in FIG. 2, reference numeral 15 indicates a mountain of the feed screw 3, and 16 indicates a valley of the feed screw 3.

Next, the operation will be described. When the injection process is completed, the plasticizing / calculating process of the raw material is started prior to the next injection. At the same time that the main screw starts rotating, the feed screw 3 starts rotating based on a preset number of rotations. Along with this, the raw material for the next shot is fed by the feed screw 3 to the raw material supply path 5
Is conveyed from the hopper 4 toward the raw material dropping port 6.

At this time, fine powder smaller than the diameter of the through hole 8 is discharged to the outside of the feed cylinder 2 through the through hole 8, so that only the pelletized raw material having a diameter larger than the diameter of the through hole 8 is fed. Is supplied to the main screw from the raw material dropping port 6 along the raw material supply path 5.

At this time, depending on the shape of the chip of the pellet or the fine powder, it may be locked by the opening of the upper bottom of the through hole 8 as shown in FIG. To be inserted into the through hole 8. Since the cross-sectional shape of the through hole 8 is trapezoidal as described above, the raw material inserted into the through hole 8 is discharged to the outside of the feed cylinder 2 as it is, and is deposited / collected in the fine powder collecting box.

Then, the raw material is transferred to the front by the rotating main screw while being plasticized and melted by the heating by the heating cylinder 7 and its own shearing heat generation. When a predetermined amount of molten raw material is stored in the front by the main screw, the measuring step is completed.

When the molded product which has been cooled on the mold clamping side is taken out, the mold is clamped again and the injection of the measured molten raw material is started.

In this embodiment, the case where the raw material is granulated into spherical pellets has been described, but the present invention is not limited to this, and a pellet-shaped raw material granulated into a polygon such as a prism or a cylinder may be used. Absent. In this case, the cross-sectional shape and diameter of the through hole 8 depend on the shape of the pellet, and are determined according to the vertical cross-sectional shape or the horizontal cross-sectional shape of the pellet.

[0023]

[Effect of the Invention] Since the present invention is configured as described above, even if fine powder is mixed in the raw material conveyed through the raw material supply path by the feed screw, only the fine powder passes through the through hole to the outside from the feed cylinder. Since it is discharged, only the pellet-shaped raw material can be supplied to the main screw. This makes it unnecessary to separate the fine powder and pellets of the raw material as a single operation before supplying the raw material to the injection molding machine,
The molding work can be simplified and workability can be easily improved.

Further, when the through hole has a cross-sectional shape that expands in a taper shape from the bottom side of the raw material supply path toward the outside of the feed cylinder, the fine powder that has passed through the opening of the through hole on the raw material supply path side depends on its shape. It is reliably discharged to the outside of the feed cylinder.

[Brief description of drawings]

FIG. 1 is a block diagram showing a main configuration of an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a main part of the feed cylinder of FIG.

3 is a cross-sectional view showing a through hole of FIG.

FIG. 4 is a cross-sectional view showing a state in which a raw material is locked in an opening of a through hole in FIG.

FIG. 5 is a front view showing a conventional example.

FIG. 6 is a front view showing a conventional example different from FIG.

[Explanation of symbols]

 1 Feed device of injection molding machine 2 Feed cylinder 3 Feed screw 8 Through hole 5 Raw material supply path

Claims (2)

[Scope of utility model registration request] 1. A feed device of an injection molding machine provided with a feed screw for feeding a pellet-shaped raw material from a feed cylinder to a main screw of an injection molding machine, wherein a feed hole of said feed cylinder has a through hole having a diameter smaller than a pellet diameter. A feed device for an injection molding machine, characterized in that the feed device is arranged at a plurality of positions from the bottom to the outside of the feed cylinder. 2. The feed of the injection molding machine according to claim 1, wherein the through hole is formed in a cross-sectional shape that tapers from the bottom side of the raw material supply path toward the outside of the feed cylinder. apparatus.