JPS601168B2 - material feeding device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a material supply device used in injection molding machines, extruders, etc. used for molding plastic materials, etc. The present invention provides a material supply device that can feed a material into a molding section by being fed into a supply screw section.

As machine equipment that manufactures products by extrusion, molding, etc. using plastic materials such as synthetic resin materials or rubber materials,
Injection molding machines, extrusion machines, etc. are generally known, and this type of mechanical equipment includes a barrel having a cylindrical hollow part and a material supply port facing the cylindrical hollow part from the outside in the flea direction, and a barrel for supplying the material. A material supply device is used that includes a material extrusion screw shaft that is inserted into the barrel and has a screw for force-feeding the material in all directions, and rotates within the barrel.

The structure and problems of a conventional example of this type of material supply device will be described below. As shown in FIGS. 1 to 5, in the general structure of this type of material supply device, the barrel 10 is
The hollow part 1 has a hollow part 11 having a cylindrical inner peripheral surface and a material supply port 13 facing the hollow part 11 from the outside in the flea direction.
The material supply screw shaft 2 inserted into the barrel 10 has an outer diameter slightly smaller than the diameter of the inner circumferential surface 12 of the hollow part, and when attached to the barrel 10', the material supply screw shaft 2 is inserted into the material supply row 3 in A screw thread 21 and a thread groove 22 are attached that start from a position slightly retreating toward the
The material bagged in the material supply row 3 is drawn into the barrel and then moved axially forward (downward in the figure).

In the injection molding machine, the material extrusion screw shaft 20 is
It may also include a structure that can move forward in the axial direction (downward in the figure) to extrude material. In the conventional example of the material supply device shown in FIGS. 1 to 3, which is mainly used in the molding process using ribbon-like or string-like materials, as shown in FIG. A material supply groove 30 is provided in the cylindrical inner circumferential surface 12 of the hollow portion 11 . The cross-sectional shape of the material supply row 3 in the direction perpendicular to the axis is such that one surface of the supply port 13 approaches the tangential direction to the outer periphery of the extrusion screw, as shown by the two-dot chain line in FIGS. 2a and 2b. Shapes are also used. In order to show the shape of the material supply groove 30, an arrow A- is shown in FIG.
Sections perpendicular to the axis at positions indicated by A', B-B' and C-C' are shown in Figures 2a, b, and c, and from the centerline of the barrel outward in the climbing direction. Figure 3 shows a developed view of the inner surface of the barrel. Figure 2a,
b, c show a situation in which the material supply groove 30 gradually decreases the depth in the flea direction along the rotation direction of the screw shaft 20,
The developed view in FIG. 3a shows a situation in which the depth of the material supply groove 30 gradually decreases along the circumferential direction, using a large number of contour lines connecting points of equal depth, and furthermore, Figure a shows the positions A-A', B-B' and C-0 of each cross section in Fig. 2, and Figure b shows the grooves at both the positions of the arrows A-A' and B-B'. The cross-sectional shape is shown to show that the barrel inner surface groove 30 gradually decreases in depth from the material supply row 3 along the direction of rotation of the screw. FIG. 3c shows a cross section in the rut direction indicated by the arrow X-X' in FIG. , indicating equal depth "front end 15
The figure shows a situation in which the depth gradually decreases after . FIGS. 4 and 5 show conventional examples of material supply devices mainly used for molding using powder or pellet-like materials. In this example, as shown in both figures, , the width dimension is approximately equal to the diameter dimension of the extrusion screw,
When the material supply port 13 having a circular or square cross-sectional shape is provided in a direction substantially perpendicular to the axial direction and a material supply groove is provided on the inner surface of the barrel, the arrows A-
Figure 5a shows the shape of the cross section perpendicular to the axial direction at the positions marked A', B-B' and C-C';
, b and c, as shown by two-dot chain lines, are provided with slight recesses primarily along the rotational direction of the screw shaft and the forward direction when the screw shaft moves.

In the above-mentioned conventional technology, "per unit rotation of the screw shaft, the amount of material fed from the material supply port into the space formed by the inner surface of the barrel, the threads of the screw shaft, and the thread thread groove surface is always a constant amount. This may cause variations in the biting amount, or the material once bitten into the screw groove cannot move forward in all directions as the screw shaft rotates, and returns to the material supply port again. In order to avoid overflowing from the supply port, or the material returning to the material supply port may accumulate in the supply port and form lumps called dumplings, stable and efficient continuous It is difficult to supply materials accurately, and the thermal history of the materials for each individual product is not uniform, resulting in problems such as variations in product quality and the occurrence of defective products.

The present invention solves the drawbacks of the conventional material supply devices described above, and provides a material supply device that efficiently and stably continuously supplies materials and maintains uniform thermal history of the materials near the supply port. It is something to do.

The present invention has a material supply port on the inner surface of the barrel that is connected to the material supply port and extends along the rotational direction of the screw shaft, and also extends along the direction of travel of the material in the direction of the screw, and is substantially orthogonal to the inclination of the screw shaft thread. A groove-shaped recess formed in the direction of the material is provided so that the material inserted into the material supply port is reliably guided into the barrel and then forced into the screw shaft. It is.

That is, a material introduction path is formed at a location where the groove on the inner surface of the barrel connects to the material supply port, and then a material introduction path is formed that extends in a direction substantially perpendicular to the direction of inclination of the screw shaft thread. This ensures the introduction of the material and the biting of the material into the screw shaft groove. The configuration of the present invention will be explained below with reference to FIGS. 6 to 12.

In the longitudinal cross-sectional view of FIG. 6, a concave groove 301 that is connected to the material supply row 3 and provided on the inner surface of the barrel extends circumferentially along the rotational direction of the screw shaft and extends along the direction in which the material travels. It extends in the axial direction to the front of the material abutment end 15. The situation in which this barrel inner groove 30 extends along the circumferential direction and the axial direction is shown by the arrows A-A' in FIG.
, B-B', C-〇 and D-〇 showing the cross-sectional shapes at the positions indicated by 〇, Fig. 7 a, b, c, and d, and Fig. 8 showing the inner surface of the barrel excluding the screw shaft. It can be understood by the diagram. That is, as shown in FIG. 7, as the cross-sectional position advances in the order of A-A', B-B', C-C', and D-D' along the traveling direction of the rattan-oriented material, The barrel inner surface groove 30 has changed its position in the circumferential direction in the counterclockwise direction (rotation direction of the screw shaft), and in FIG. The situation is shown in which the robot is moving forward in all directions.

In FIG. 8, a portion indicated by a two-dot chain line shows the extension of the groove 30 on the inner surface of the barrel half (the side not including the material supply row 3) that has been removed in cross section. FIG. 9 is a developed view of the inner surface of the barrel viewed radially outward from the center of the barrel to show the shape of the inner cavity of the barrel in the embodiments of FIGS. 6 to 8. FIG. The line marked with 00 in the figure indicates the position corresponding to the edge of the material supply port 13, marked with the symbol X in FIG. 9th
In Figure a, a large number of straight lines and arcuate curves drawn in parallel with each other are depth contour lines that connect parts of the barrel inner surface groove 30 that have the same depth. Figure 9 b, c and d
Each figure is indicated by the arrows B-B' and C-C on the same figure a.
It shows the cross-sectional shape of the barrel inner surface groove at the positions marked with ' and D-. The barrel inner surface groove 30 is
The situation in which the material is stretched in the vicinity of the material supply port 13 along the rotational direction of the screw shaft, and then in both the circumferential direction and the axial direction can be understood from each figure in FIG.

The three grooves on the inner surface of the barrel, which are shown extending diagonally in FIG. The material bite portion 32 is formed by gradually decreasing the amount. 10 and 11 respectively show other embodiments of the barrel inner surface groove, and are shown in a developed view similar to FIG. Well, it extends simultaneously in the direction of rotation of the screw shaft and in the direction of the ball, and as shown in figures b, c, and d of each example, the arrows B-B', C-〇, and arrows shown in figure a respectively There are differences in the cross-sectional shapes at the position D-〇, and the cross-sectional shapes of these concave foundations are appropriately selected depending on the characteristics of the material used. Figure 12 shows the processing of the inner surface of the barrel, particularly the processing of the groove 30, after dividing the barrel into two and processing the inner surface of each member. This shows the situation in which the combination is completed.

The material combining device of the present invention has the above-mentioned structural requirements, thereby providing the following effects.

Connected to the material supply port on the inner peripheral surface of the barrel, it extends in the direction of rotation of the screw shaft, and also extends toward the direction in which the material travels along the shaft, and is approximately perpendicular to the direction of inclination of the thread of the screw. By having a concave groove formed in the direction, the material inserted into the material supply port is reliably sucked into the concave groove of the screw shaft without causing overflow or retention phenomena at the material supply port. , then moved through the concave groove by being pushed by the screw thread and pushed into the thread groove, ensuring the supply of material.As a result, not only the forming process is carried out smoothly without any stagnation, but also individual The thermal history of the materials for each product is maintained uniformly, resulting in highly accurate quality.

[Brief explanation of the drawing]

FIG. 1 shows the structure of a material supplying device according to the prior art. FIG. Arrow A-A in Figure 1
Figure 3a is a cross-sectional view perpendicular to the axis at the positions indicated by ', B-B' and C-○, in the example of Figures 1 and 2. The exploded view of the inside of the barrel looking toward the direction, Figure 3b, shows the arrow A- on Figure 3a.
A cross-sectional view at the positions indicated by A' and B-B',
FIG. 3c is a sectional view at the position indicated by the arrow C-○ on FIG. 3a, FIG. 4 is a longitudinal sectional view showing another example of the prior art, and FIG. 4 Arrows A-A', B-B on Figure 4
6 is a cross-sectional view perpendicular to the axis at the positions indicated by ' and C-C', and FIG. The vertical cross-sectional view at the position shown in FIG. 7 is shown by the arrows A-A', B-B',
The sectional view in the direction perpendicular to the axis at the positions indicated by C-C' and D-○, FIG. Figure 9 shows
In the embodiment according to the present invention, the inner surface of the barrel is shown in a developed view a when viewed from the center line toward the outside in the radial direction, and on the same developed view,
The cross-sectional views at the positions marked with arrows B-B', C-C', and D-○, and FIGS. 10 and 11, correspond to the embodiments of the present invention shown in FIGS. A developed view and a partial sectional view illustrating the shape of the inner groove of the barrel in different embodiments,
FIG. 12 is a sectional view taken in a direction perpendicular to the rattan, showing the structure of the barrel that allows processing of the inner surface of the barrel according to the present invention. 10... Barrel, 11... Cylindrical hollow part, 12
...Inner circumferential surface of hollow part "13...Material supply port, 14...Rear end of material supply port" 15...Front end of material supply port, 20...Material extrusion screw core, 21...
...Screw shaft thread 22...Screw shaft thread record, 30...・0 barrel inner groove, 31... Material introduction path, 32...
...Material digging part. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 9 Figure 8 Figure 10 Figure 11 Figure 12

Claims (1)

[Claims] 1. A barrel 10 having a cylindrical hollow part 11 and a material supply port 13 facing the cylindrical hollow part 11 from the outside in the radial direction;
In a material supply device comprising a material extrusion screw shaft 20 having a thread 21 and a thread groove 22 for pumping the material and rotating within the barrel hollow part 11, the material is A barrel inner surface recess is connected to the supply port 13 and extends in the rotational direction of the screw shaft 20 and in the axial material extrusion direction, and is formed in a direction substantially perpendicular to the inclination direction of the thread 21. A material supply device characterized by having a groove 30.