JPS588527Y2 - Multiple molding mold - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a multiple molding mold equipped with a hot runner mechanism.

A multi-layer mold that uses a hot runner mechanism can keep the resin in the hot runner mechanism in a molten state at all times, excluding the resin in the cavity, and feed it directly into the cavity in the next molding operation, reducing wastage of molding material. This has the effect that the molded product inside the cavity can be directly separated from the resin inside the hot runner mechanism.

However, in conventional multiple molding molds, a cavity plate that moves relative to both core plates is interposed between a movable core plate that can reciprocate with respect to a fixed core plate, and the fixed core plate is attached to this cavity plate. A penetrating hot runner bush is protruded.

Therefore, when the mold is closed, the nozzle of the injection molding machine is brought into contact with the nozzle contact surface of the hot runner bushing to press-fit the resin, but when the mold is opened after the resin is press-fitted, the cavity plate and the movable core are separated from the fixed core plate. As the plate retreats, the hot runner bushing fixed to the cavity plate also moves together, creating a distance equal to the stroke between the nozzle contact surface and the nozzle.

Therefore, there is a problem in that the resin flows down from the nozzle and adheres to the fixed core plate.

This invention was developed based on the above circumstances, and its purpose is to slide the hot runner bush fixed to the fixed core plate into the fitting hole of the hot runner block between the cavity plates. The hot runner bushing and the nozzle are in contact with each other both during mold closing and mold opening to prevent resin leakage, and the shutter sleeve is slidably fitted to the hot runner bushing to close the mold. An object of the present invention is to provide a multi-layer mold that can prevent resin leakage from the resin discharge port regardless of the size of the mold opening stroke by blocking the resin discharge port of the hot runner bushing with a shutter sleeve when the mold is opened. It is something to do.

Hereinafter, this invention will be explained based on one embodiment shown in the drawings.

In the figure, 1 is a fixed core plate, and 2 is a movable core plate.
A cavity plate 3 that is movable relative to 2 is interposed.

The fixed core plate 1 and cavity plate 3 and the movable core plate 2 and cavity plate 3 are connected by connecting rods 4, 4, respectively.

Further, the fixed core plate 1 and the movable core plate 2 are each provided with a plurality of cores 5, and on both sides of the cavity plate 3 facing these cores 5... has multiple cavities 6...
・ is provided.

Further, a base end portion of a hot runner bush 7 is fixed to the center of the fixed core plate 1, and a nozzle contact surface 8 located on the outer surface of the fixed core plate 1 is attached to this end surface.
is formed.

This nozzle contact surface 8 is adapted to come into contact with a nozzle 9 of an injection molding machine (not shown).

Furthermore, the hot runner bush 7 has a small diameter portion 7a on the base end side.
The tip side is formed into a sliding part 7b with a large diameter part, and one end communicates with the nozzle contact surface 8 at its axial center, and the other end branches off and penetrates in the radial direction, and a resin discharge port is formed on the side thereof. 10a
, 10a is bored.

The hot runner bush 7 passes through the stripper plate 11 and is inserted into a through hole 12 formed in the cavity plate 3.

Further, a through hole 13 is bored in the middle of the through hole 12 and perpendicular to the through hole 12, and a hot runner block 14 in which a heating element 14a is embedded is installed inside the through hole 13. has been done.

This hot runner block 14 is provided with a fitting hole 15 that tightly fits into the sliding portion 7b of the hot runner bushing 7, and is perpendicular to the fitting hole 15 to form the respective cavities 6... A communication hole 16.16 communicating with... is bored.

Further, a shutter sleeve 17 is provided in the through hole 12 of the cavity plate 3 and is fitted into the hot runner bush 7 so as to be slidable in the axial direction.

The shutter sleeve 17 has an inner diameter that closely fits the sliding portion 7b of the hot runner bushing 7, and has an inner diameter at one end that engages with the stepped portion 7C of the hot runner bushing 7. A collar 17a is formed.

Further, a fixing ring 18 is fixed to the small portion 7a of the hot runner bush 7, and a coiled spring 19 is interposed in a compressed state between the fixing ring 18 and the inner flange 17a of the shutter sleeve 17. There is.

The restoring force of the spring 19 presses the shutter sleeve 17 against the hot runner block 14.

However, in the multiple molding mold configured in this way, the resin discharge ports 10a, 10a of the flow path 10 of the hot runner bush 7 and the communicating holes 16, 16 of the hot runner block 14 face each other during mold clamping. When the mold is opened, the resin discharge ports 10a, 10a of the flow path 10 of the hot bush 7 are connected to the communication hole 1 by the stroke thereof.
Resin discharge ports 10a, 10a spaced apart from each other are closed by the inner wall of the shutter sleeve 17, and the communication hole 16.16 is closed by the outer wall of the hot runner bush 7.

In other words, it is designed to function as a sharai.

Next, the operation of the multiple molding die configured as described above will be explained.

First, as shown in FIG. 2, in the mold clamping state, the resin discharge port 10 a of the flow path 10 of the hot runner bush 7
, 10a and the communication hole 16 of the hot runner block 14
．． 16 is in communication.

In this state, when the nozzle 9 of the injection molding machine is brought into contact with the nozzle contact surface 8 and the heated and melted resin a is injected, the resin a is transferred from the flow path 10 to the resin discharge ports 10a, 10a-+the communication hole 16.
．． 16 and is press-fitted into each cavity 6 . . . to obtain a molded product 6 .

Next, when opening the mold, move the movable core plate 2 in the direction of the arrow, the movable core plate 2 will be separated from the cavity plate 3, and the movable core plate 2 will be separated from the cavity plate 3.
is separated from the fixed core plate 2.

Therefore, as shown in Fig. 3, molded product b... is a stripper play).
It will be released from the mold.

At this time, the hot runner bush 7 is fixed to the fixed core plate 1, but since the shutter sleeve 17 is pressed against the cavity plate 3 by the spring 19, the hot runner bush 7 is fixed to the fixed core plate 1. It slides inside the shutter sleeve 17 along with the movement.

Therefore, the resin discharge ports 10a, 10a of the flow path 10 are cut off by the inner wall of the shutter sleeve 17, and the communication hole 16.16 is cut off by the outer wall of the hot runner bush 7, so that the resin in the flow path 10 and the flow hole 16.16 is cut off. a is maintained in a heated and molten state.

Furthermore, at this time, due to the mold opening, the stepped portion 7C of the hot runner bushing 7 comes into contact with the inner flange 17a of the shutter sleeve 17, and the mold opening progresses further and the shutter sleeve 17
Even if the cavity plate 3 is separated, the shutter sleeve 17 maintains the fitted state with the hot runner bushing 7 by the restoring force of the spring 19.

Therefore, the resin discharge port 10 of the hot runner bush 7
a and 10a are held in a closed state by the shutter sleeve 17, and the resin a does not leak to the outside.

In addition, even in the mold open state, the hot runner bushing 7 fixed to the fixed core plate 1 is in a stopped state, and the nozzle contact surface 8 and the nozzle 9 are always kept in pressure contact, and the resin is A does not flow down.

Furthermore, the resin a remaining in the flow passage 10 and the communicating holes 16, 16 is press-fitted into the cavity 6 during the next molding, so that there is no waste of the resin a, which is economical.

As explained above, this invention enables the hot runner bush fixed to the fixed core plate to slide into the fitting hole of the hot runner block in the cavity plate, and also allows the nozzle contact surface of the hot runner bush to be attached to the fixed core plate. Because it is provided on the outside surface of the mold clamp, the nozzle of the injection molding machine can be kept in contact with the nozzle contact surface of the hot runner bushing at all times when the mold is opened, and the resin can be prevented from flowing down from the nozzle. can.

Further, the resin in the hot runner bush and the hot runner block can be used for the next molding process, which is economical since no resin is wasted.

Furthermore, a shutter sleeve is slidably fitted to the hot runner bushing, and when the mold is opened, the shutter sleeve shuts off the regreasing outlet of the hot runner bushing, so regardless of the size of the mold opening stroke, the resin This has the effect of being able to prevent resin leakage from the discharge port.

Another advantage is that the state of bonding between the nozzle contact surface and the nozzle can be easily confirmed from the outside.

[Brief explanation of the drawing]

The drawings show one embodiment of this invention, in which Fig. 1 is a side view of a multi-layer mold, Fig. 2 is a longitudinal sectional front view taken along line III in Fig. 1, and Fig. 3 is a state in which the mold is opened. It is a front view with a part notched away. 1... Fixed core plate, 2... Movable core plate, 3... Cavity plate, 7
...Hot runner bush, 8...Nozzle contact surface, 9...Nozzle, 10 a...
... Resin discharge port, 14 ... Hot runner block, 15 ... Fitting hole, 17 ... Shutter sleeve, 19 ... Spring, 7b ...・
...Sliding part, 12...Through hole.

Claims (1)

[Scope of utility model registration request] A fixed core plate, a hot runner bush that is fixed to the fixed core plate, has a nozzle contact surface at its base end that contacts a nozzle of an injection molding machine, and has a resin discharge port at a sliding part in the middle, and this hot runner. a cavity plate having a through hole that fits into the bushing and is capable of reciprocating with respect to the fixed core plate; and a cavity plate that is provided within the cavity plate and slidably fits into the sliding portion of the hot runner bushing. A hot runner block is provided with a fitting hole that communicates with the resin discharge port when the mold is clamped and is interrupted by the outer peripheral surface of the sliding part of the hot runner bush when the mold is opened, and a hot runner block that has a fitting hole in the sliding part of the hot runner bush. A shutter sleeve is fitted to be able to slide freely in the axial direction, and a shutter sleeve is also fitted to the hot runner bush and is compressed when the mold is closed, retracting the shutter sleeve from the resin discharge port and restoring when the mold is opened. 1. A multi-layer molding die, comprising: a spring that uses force to cause the shutter sleeve to face the resin discharge port and to shut off the resin discharge port.