JPH09174623A - Elector device of vertical injection molder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a positioner for exclusive use by giving an ejector pin a positioning function. SOLUTION: When a turntable 2 stops, a hydraulic cylinder 17 operates immediately and inserts the top of an ejector pin 19 into a positioning hole 10a. As a result, the turntable 2 is placed in a prescribed position precisely. As the lower part 10b of the positioning hole 10a is tapered toward the bottom and the upper end 19a of the ejector pin 19 is tapered to the tip part, the ejector pin 19 is inserted correctly in the positioning hole 10a. When a melded product within a lower die 1 solidifies moderately, the hydraulic cylinder 17 operates again and pushes the ejector pin 19 into the lower die 1 on the turntable 2, extruding the molded product.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ejector device for a vertical injection molding machine using a turntable.

[0002]

2. Description of the Related Art As a vertical injection molding machine, as shown in FIG. 4, a turntable 2 having a pair of lower molds 1 and 1 is provided.
The tie bar (center shaft) 3 of the book is horizontally rotated to position it at a predetermined position by a positioning device (not shown), and the upper die 5 attached to the movable plate 4 is clamped by a hydraulic cylinder or the like. It is lowered by (not shown) to clamp the mold, and the resin is injected into the cavities of the molds 1 and 5, and the turntable 2 is rotated to move it from directly under the upper mold 5 to another position. It is known that a molded product in the lower mold 1 is taken out by an ejector device (not shown). The movable platen 4 is supported by three tie bars 3, 6 and 6, and the turntable 2 is rotatably supported by a fixed platen (fixed member) 7.

[0003]

In the above-mentioned conventional vertical injection molding machine, the positioning device for accurately stopping the turntable 2 at a predetermined position and the ejector device for taking out a molded product from the lower mold 1 are dedicated. However, there is a problem that the entire structure becomes complicated because they are provided separately.

[0004]

In order to solve the above problems, the invention according to claim 1 is such that a turntable having at least a pair of lower molds is located below an upper mold which is moved up and down by a mold clamping device. In a vertical injection molding machine supported by a fixed member and rotatably provided around a central axis, a positioning hole is formed vertically through the turntable, and a driving hole is formed below the turntable. An ejector pin is provided, which is raised by a device to insert the upper portion into the positioning hole, positions the turntable at a predetermined position, and is further raised to push the molded product from the lower mold.

It is desirable that the lower part of the positioning hole is tapered downward and the upper end of the ejector pin is tapered.

[0006]

1 to 3 show an embodiment of an ejector device of a vertical injection molding machine according to the present invention. The same members as those in FIG. 4 are designated by the same reference numerals, and detailed description thereof will be omitted.

Reference numeral 10 is a bush. Push 10
2 are provided on the turntable 2 in a point symmetry with respect to the central axis 3 at intervals of 180 degrees, and a circular positioning hole 10a penetrating vertically is formed in the turntable 2. The lower part of the positioning hole 10a has a downwardly widened tapered shape. The bush 10 is detachably fixed to the turntable 2 by a C-shaped retaining ring 11.

A stopper 12 is fixed to the lower surface of the peripheral portion of the turntable 2 with a bolt 13. Stopper 1
2 is symmetrical with respect to a straight line orthogonal to a straight line connecting the centers of the two bushes 10, 10.

On the rotating surface of the stopper 12, two cushioning members 14, 14 are fixedly provided to a fixture 15. The two cushioning members 14, 14 are for abutting the stopper 12 to stop the turntable 2 in a cushioning manner, and are arranged symmetrically with respect to a straight line connecting the centers of the bushes 10, 10. The rotation stop angle of the turntable 2 by the stopper 12 and the cushioning members 14, 14 is
Due to the cushioning function of the cushioning member 14, it becomes approximately 180 degrees.

Reference numeral 17 is a hydraulic cylinder (driving device).
It is. The hydraulic cylinder 17 is provided vertically below the bush 10 (the lower bush in FIG. 1) at a rotational position apart from the upper die 5 (FIG. 4) and is fixed to a tubular mounting tool 18. An ejector pin 19 having a circular cross section is vertically inserted into a hole 18a of the mounting tool 18, and is screwed to a piston rod 17a of a hydraulic cylinder 17 and fixed with a screw 20. The ejector pin 19 is the piston rod 1
It is adjustable up and down with respect to 7a.

The ejector pin 19 has a tapered upper end 19a, and has an outer diameter equal to the inner diameter of the positioning hole 10a (strictly, slightly smaller) and can be inserted into the positioning hole 10a. It is said that. The hydraulic cylinder 17 is configured to operate in two stages. The first operation inserts the upper portion of the ejector pin 19 into the positioning hole 10a, and the next operation causes the ejector pin 19 to rotate.
It sticks out above. The hydraulic cylinder 17 is provided with a proximity switch 22 that detects the end of the first operation of the hydraulic cylinder 17 and a proximity switch 23 that detects the end of the next operation. A bush 24 is fitted into the upper end of the hole 18a of the fixture 18 and fixed by a screw 25.

Reference numeral 27 is a hydraulic motor (actuator) for alternately turning the turntable 2 in the opposite direction,
Reference numeral 28 is a guide member for guiding the turntable 2.

Next, the operation of the ejector device of the vertical injection molding machine according to the present invention having the above structure will be described. The turntable 2 is rotated clockwise from the state shown in FIG. 1 by the hydraulic motor 27, and the stopper 12 is brought into contact with the buffer member 14 on the left side in FIG. 1 to stop. By this rotation of the turntable 2, the two lower molds 1 and 1 are exchanged with each other.

When the turntable 2 stops, the hydraulic cylinder 17 immediately operates to insert the upper portion of the ejector pin 19 into the positioning hole 10a. As a result, the turntable 2 is accurately positioned at a predetermined position. In this case, since the lower portion 10b of the positioning hole 10a is tapered downward and the upper end 19a of the ejector pin 19 is tapered, the positioning member 10a is buffered by the buffering action of the buffering member 14. The ejector pin 19 can be accurately inserted into the positioning hole 10a even if the center of the ejector pin is slightly deviated from the central axis of the ejector pin 19.

In the above state, the upper die 5 is clamped to the upper lower die 1 in FIG. 1 and the resin is injected into those cavities. Further, when the molded product in the lower mold 1 on the lower side in FIG. 1 is appropriately solidified, the hydraulic cylinder 17 is actuated again and the ejector pin 19 is pushed up into the lower mold 1 on the turntable 2 to move the molded product. Push out.

When the injection of the resin and the extrusion of the molded product are completed in this way, the hydraulic cylinder 17 contracts and the ejector pin 19 is pulled out downward from the positioning hole 10a.
The hydraulic motor 27 operates in the opposite direction to rotate the turntable 2 counterclockwise. Thereafter, similarly to the above, the ejector pin 19 is raised by the operation of the hydraulic cylinder 17 to position the turntable 2, and the molded product is pushed out.
The present invention can also be applied to an injection molding machine in which the turntable 2 is rotated in one direction to a predetermined angle.

[0017]

As described above, in the ejector device of the vertical injection molding machine according to the present invention, the turntable having at least a pair of lower molds is located below the upper mold which is moved up and down by the mold clamping device. In the vertical injection molding machine supported by a fixed member and rotatably provided about a central axis, a positioning hole is vertically formed through the turntable, and below the turntable, It is lifted by the driving device and the upper part is inserted into the positioning hole,
After the turntable is positioned at a predetermined position, the ejector pin is further raised to push out the molded product from the lower mold, and in addition to the function of extruding the molded product,
Since it also has the positioning function of the turntable, it is possible to omit a dedicated positioning device, and therefore the overall structure can be simplified and the cost can be reduced.

When the lower portion of the positioning hole is tapered downward and the upper end of the ejector pin is tapered, the action of the cushioning member causes a large variation in the stop position of the turntable. However, there is an advantage that it does not cause trouble.

[Brief description of the drawings]

FIG. 1 shows an embodiment of an ejector device of a vertical injection molding machine according to the present invention, and is a plan view in which a part of a turntable is cut away.

FIG. 2 is a sectional view taken along the line (II-II) of FIG.

FIG. 3 is a sectional view taken along the line (III-III) of FIG. 1;

FIG. 4 is a schematic sectional view of a vertical injection molding machine.

[Explanation of symbols]

 1 Lower Mold 2 Turntable Gun Table 3 Tie Bar (Center Shaft) 5 Upper Mold 7 Fixing Plate (Fixing Member) 10 Bushing 10a Positioning Hole 10b Lower 17 Hydraulic Cylinder (Drive) 19 Ejector Pin 19a Upper End

Claims (3)

[Claims] 1. A turntable having at least a pair of lower molds is provided below an upper mold, which is moved up and down by a mold clamping device, and is supported by a fixing member so as to be rotatable about a central axis. In the vertical injection molding machine, a positioning hole is vertically formed through the turntable, and a lower part of the turntable is lifted by a driving device and an upper part is inserted into the positioning hole, so that the turntable is predetermined. An ejector device for a vertical injection molding machine, comprising an ejector pin which is positioned at a position and further raised to push out a molded product from a lower mold. 2. The ejector device for a vertical injection molding machine according to claim 1, wherein the lower portion of the positioning hole is tapered downward. 3. The ejector device for a vertical injection molding machine according to claim 1, wherein an upper end of the ejector pin has a tapered taper shape.