JPH0650175Y2 - Mold for molding plastic containers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a mold for molding a plastic container.

(Prior Art) In a plastic container 1 used for a garbage basket or the like, as shown in FIG. 7, a large number of mesh holes 3 are formed in the upper and lower middle portions of a container body 2 having a bottomed rectangular tube over the entire circumference. At the same time, there is a container body 2 provided with folding ribs 4 for reinforcement or the like on the outer periphery of the upper end opening. Conventionally, as a mold for molding the container 1 having the mesh holes 3 of this kind, there are a mold having a mesh hole forming portion in a male mold, a mold having a mesh hole forming portion in a female mold, and the like.

(Problems to be solved by the invention) With a mold having a mesh hole forming part in a male mold, it is structurally difficult to divide the male mold into a plurality of parts and expand and contract the structure. Therefore, there is a drawback that the mesh holes 3 of the container 1 are collapsed by the mesh hole forming portion at the time of die-cutting and the finished state is deteriorated.

On the other hand, when the mesh hole forming portion is provided on the female mold side, the female mold itself can be easily expanded and contracted, so that there is an advantage that the container 1 in which the mesh holes 3 are not collapsed can be molded.

However, when molding the container 1 in which the folding ribs 4 are provided on the outer circumference of the opening end of the container body 2 in the circumferential direction, a mold that can be expanded and contracted is hooked on the folding ribs 4 in the conventional structure, and thus die cutting is impossible. And cannot be molded. Therefore, conventionally, when molding the container 1 having the folding ribs 4, it was necessary to provide the mesh hole molding portion on the male side.

In view of the above points, the present invention provides a metal mold for molding a plastic container capable of easily and cleanly molding a plastic container having mesh holes and folding ribs.

(Means for Solving the Problem) The present invention relates to a plastic container molding die for molding a plastic container 1 having a male mold 15 and a female mold 20 and having a mesh hole 3 and a folding rib 4. The mold 20 is a fixed mold 22 having a bottom molding part 22A of the container 1, and a mesh hole molding part that can be inserted into and removed from the fixed mold 22 and can be expanded and contracted in the radial direction.
Radially divided multiple sliding molds with 23
And the folded rib forming part 25 that is superposed on the sliding mold 24.
And a floating mold 26 which is movable in the mold axis direction, and holds the contracted posture of the sliding mold 24 in a molding state in which the female mold 20 and the male mold 15 are matched. A sliding lock pin 37 for restraining the sliding outward in the radial direction is provided so as to penetrate the floating mold 26 in the mold axial direction, and the mesh hole molding is performed in a state where the lock of the sliding lock pin 37 is released. A guide portion 26A for slidingly guiding the sliding die 24 in the radial direction for releasing the portion 23 is provided in the floating die 26 at a portion overlapping with the sliding die 24, and the mesh hole forming portion 23 is released. It is characterized in that it is provided with means 35 for releasing the folded rib forming portion 25 of the floating die 26 in a molded state through the movement of the floating die 26 in the axial direction of the die.

(Operation) When the container 1 is taken out after molding, the lock of the slide lock pin 37, which holds the sliding outward of the sliding die 24 in the radial direction and holds the reduced posture of the die 24, is released. And a plurality of sliding dies 24 of the female die 20 are expanded in the radial direction to form the mesh hole forming portion 23 in the container 1
When the sliding die 24 is pulled out from the mesh holes 3 of the above, the sliding die 24 is released by being guided by the guide portion 26A formed in the floating die 24 in the overlapping portion thereof. Next, when removing the folded rib forming portion 25 of the floating mold 26 from the folded rib 4 of the container 1,
The mold is released by moving in the direction of the mold axis. Therefore, the sliding type 24 that can be expanded and contracted and the floating type that is divided from this
By providing 26, even the container 1 having the folding ribs 4 can be molded without breaking the mesh holes 3.

(Embodiment) An embodiment of the present invention will be described in detail below with reference to the drawings.

In FIG. 3, reference numeral 5 denotes an injection molding machine, which includes a fixed die plate 6, a movable die plate 7, a main guide shaft 8, a mold clamping cylinder 9, and the like, and between the fixed die plate 6 and the movable die plate 7. Is provided with a plastic container molding die 10. 11 is a screw type injection device for melting and filling a plastic material into the molding machine 5, such as a hopper 12,
The screw unit 13 and the injection cylinder 14 are provided.

The mold 10 is configured as shown in FIGS. 1 and 2. That is, in FIGS. 1 and 2, reference numeral 15 is a movable-side male die, and the molding surface is formed smoothly according to the shape of the inner surface of the container 1. This male die 15 is movably mounted by a bolt 16. It is attached to plate 17. Movable mounting plate 17
Is mounted on the main guide shaft 8 together with the movable die plate 7,
Further, a stopper bolt 18 which is inserted into the movable die plate 7 so as to be engageable with the movable mounting plate 17 is screwed. The stopper bolt 18 has a movable mounting plate.
A spring 19 for urging the movable die plate 7 and the movable die plate 7 in the separating direction.
Has been overfitted.

A fixed-side female mold 20 has a nozzle gate 22A attached to the fixed die plate 6 through a fixed mounting plate 21 and a bottom molding portion 22A of the container, and the fixed mold 22.
A plurality of sliding dies that can be freely inserted into and removed from, and expandable and contractible in the radial direction, and that have a mesh hole forming portion 23 and are divided in the radial direction.
24, and a folded rib forming portion that is superposed on the sliding die 24
It comprises a floating die 26 having 25 and movable in the die axial direction, and a movable die 28 having a folded rib forming portion 27. Fixed type 22
A tapered fitting concave portion 29 and a cutout portion 30 are formed in the. The sliding die 24 is arranged in each of the notches 30 of the fixed die 22, and fitting projections 31 are provided so as to expand and contract in the radial direction by being fitted into and removed from the fitting recesses 29. A sliding guide pin 32 fixed to the fixed die 22 is inserted into the sliding die 24 so that the sliding die 24 expands and contracts. The sliding range of the sliding mold 24 is restricted by a stopper bolt 33 screwed to the fixed mold 22, and is urged by a spring 34 in the expanding direction. A stopper bolt 35 screwed into the fixed die 22 is inserted into the floating die 26, and the sliding die 24 is slid in the radial direction on the floating die 26 in the overlapping portion with the sliding die 24. Guide portion 26A is formed, and the stopper bolt 35 is fixed to the fixed die 22 when the sliding die 24 is fully expanded.
And the floating type 26 are regulated. The fixed die 22, the floating die 26, and the movable die 28 are inserted and supported by the main guide shaft 8, and the movable die 28 can be ejected by a knockout pin. Sliding lock pins 37 are attached to the movable die plate 7 so as to correspond to the tapered recesses 36 of the respective sliding dies 24. The sliding lock pins 37 are attached to the movable mounting plate 17, the floating die 26,
A tapered portion 38 at the tip of the sliding die 24 penetrates the movable die 28 and is removably fitted into the tapered recessed portion 36 of the sliding die 24 to lock the sliding die 24.

In the above-mentioned structure, when molding, as shown in FIG.
After the mold 10 is clamped, the injection device 11 fills the molding space in the mold 10 with the plastic material through the nozzle gate 22A.

When the molding is completed, the mold clamping cylinder 9 is contracted, and the movable die plate 7 is moved along the main guide shaft 8 in the direction indicated by the arrow a. When the movable die plate 7 moves until the head of the stopper bolt 18 contacts the movable die plate 7, the taper portion 38 of the slide lock pin 37 causes the taper recessed portion 36 of the slide die 24 as shown in FIG. And unlock the sliding type 24. When the movable die plate 7 is further moved in the direction indicated by the arrow a, as shown in FIG.
28 moves integrally with the movable die plate 7, and within the range where the head of the stopper bolt 35 abuts on the floating die 26, the sliding die 24 and the floating die 26 are pushed in the direction indicated by the arrow a by the spring 34.
The distance between the fixed mold 22 and the floating mold 26 increases. At this time, as the distance increases, each sliding die 24 slides into the sliding guide pin 32.
When the sliding molds 24 slide outward in the radial direction along the direction of arrow b, they are guided by the guide portion 26A of the floating mold 26 in which the sliding lock pin 37 is inserted. The mesh hole forming portion 23 does not come out from the mesh hole 3 of the container 1 in the radial direction and does not collapse the mesh hole 3. When the head of the stopper bolt 35 comes into contact with the floating mold 26, the floating mold 26 does not move, so that the folded rib forming portion 25 of the floating mold 26 is released from the folded rib 4 of the container 1. That is, the folded rib forming portion 25 is released by the relative movement of the floating die 26 in the direction of the die axis, and the stopper bolt 35 is formed in the folded rib forming portion.
It is said to be 25 releasing means. Then the movable die plate 7
Move in the direction of arrow a, then knockout pin 39
Since it abuts on the movable die 28, as shown in FIG.
The container 1 is removed from the container. Then, the container 1 may be removed from the movable mold 28. Therefore, in this way, even though the container 1 has the folding ribs 4, the sliding die 24 is inserted from the mesh holes 3 of the container 1.
The mesh hole forming part 23 can be removed, and the container 1 with a clean finish can be formed.

Further, by using the floating type 26 and the sliding type 24 with different types of die heights (lengths in the die axial direction), the mesh 3
The portion occupied by can be made large, medium or small by the container 1.

When the mold clamping cylinder 9 is extended during mold clamping, the mold 10 can be clamped by the reverse operation.

(Effect of the Invention) As described in detail above, according to the present invention, even in the container 1 having the folding ribs 4, the folding ribs 4 are not broken or the mesh 3 is not broken, and the mesh 3 The occupying portion can be made large, medium or small according to the container 1, and the container 1 can be easily and cleanly molded.

[Brief description of drawings]

The drawings show one embodiment of the present invention. Fig. 1 is a sectional view of a mold, Fig. 2 is a view taken along the line II-II of Fig. 1, Fig. 3 is an overall elevational view, and Figs. FIG. 6 is a sectional view showing the operation, and FIG. 7 is a sectional view of the container. 1 ... Plastic container. 3 ... mesh holes, 4 ... folded ribs,
15 ... Male type, 20 ... Female type, 22 ... Fixed type, 23 ... Mesh hole forming section,
24 ... Sliding type, 25 ... Folded rib forming part, 26 ... Floating type, 28 ...
Movable type.

Claims (1)

[Scope of utility model registration request] 1. A mold for molding a plastic container, which comprises a male mold (15) and a female mold (20) and molds a plastic container (1) having a mesh hole (3) and a folding rib (4), The female mold (20) is a bottom molding part (22A) of the container (1).
(22) having a groove, and a plurality of slides which can be inserted into and removed from the fixed die (22) and can be expanded and contracted in the radial direction and which have a mesh hole forming portion (23) and which are divided in the radial direction. Mold (24)
And a floating type (26) that is superposed on the sliding type (24) and has a folded rib forming part (25) and is movable in the axial direction of the type.
And, in the molding state in which the female mold (20) and the male mold (15) are matched with each other, the sliding mold (24) is held in the contracted posture and slid outward in the radial direction thereof. A sliding lock pin (37) for restraining movement is provided through the floating mold (26) in the axial direction of the mold, and the mesh hole forming part (in the state where the lock of the sliding lock pin (37) is released ( A guide part (26A) for slidingly guiding the sliding mold (24) in the radial direction to release the mold 23) is provided in the floating mold (26) at the overlapping portion with the sliding mold (24).
Furthermore, the folded rib forming part (25) of the floating mold (26) is moved to the floating mold (26) while the mesh hole forming part (23) is released.
A mold for molding a plastic container, comprising a means (35) for releasing the mold through movement of the mold in the axial direction.