JPS5931393Y2 - Sprue lock mechanism close to side core - Google Patents

Description

[Detailed description of the invention] The present invention relates to a square mold for plastic molding, and relates to a sprue lock mechanism for automatically pulling out a sprue formed by solidifying molten plastic in a molten plastic injection channel. .

Figure 1 shows an example of a mold commonly used in the past.
The structure is such that the fixed mold plate 3 and the side cores 2a, 2b are sandwiched between the fixed side mounting plate 1 and the movable mold plate 12 and pressed.

When pressed in the direction of arrow A, the pair of side cores 2a, 2
b contact the slopes of the locking blocks 4, 4, approach each other, and come into close contact at the abutting surfaces 5.

Inclined bars 6 and 6 serve as guides to separate the pair of side cores 2a and 2bk from each other when the mold is opened in the direction of arrow B.

In order to inject molten plastic into the cavity (not shown) formed in the side cores 2a, 2b and the fixed mold plate 3, the sprue bush 7 passes through the fixed side mounting plate 1 button and the fixed mold plate 3. It is provided.

After injecting molten plastic into the sprue bushing hole 8 to mold the product, the plastic solidified in the sprue bushing 7 becomes the sprue 9, and in order to pull it out from the sprue bushing, the above hole 8 widens in the mold opening direction. A tab is attached.

1F is a butting flock for reinforcement.

In order to automatically pull out the sprue 9 solidified within the hole 8 of the bushing during the mold opening operation, a chip-like structure is generally used.

(1) As long as conditions such as the shape of the product to be formed permit, the sprue bushing 7 has its center line aligned with the side cores 2a and 2.
It is provided to match the abutment surface 5 of b.

(11) Sprue locks 10, 1 (n) are provided at the contact portions between the sprue 9 and the side cores 2a, 2b, which are buttoned and protrude from the sprue 9 into the side cores 2a, 2b.

Specifically, recesses are formed in the side cores 2a and 2b, the button is pressed, and molten plastic is injected and solidified to form the sprue locks 10 and 11.

According to the configurations (i) and (ii) above, (a) when the side cores 2a y2b are opened in the direction of arrow B, the side cores 2b, 2b are sprue-locked,
Move in the 1-shaped listening direction (arrow B) with i oi sandwiched in,
Pull out sprue 9 from inside sprue bush T in the direction of arrow B'J.

(b) Along with the above operation, a pair of side blocks 2a
, 2M; t Guided by the incline bar 6.6, it is separated to the left and right, and released by the sprue lock 10.10 that was inserted.

FIG. 2 is an external view of the sprue 9 integrally formed with a sprue lock, and FIG. 3 is a plan view of the sprue 9.

13 is a product made by plastic molding.

Actually, the actions (a) and (b) above proceed simultaneously, and the sprue is pulled out and the sprue lock is released.

However, depending on the shape of the product to be plastic molded, it may not be possible to provide the sprue lock 10 on the abutment surface 5 of the side core as described above.

For example, when molding a tubular product with a recess near the center as shown in Figure 4, align the abutting surfaces 5' of the side cores 2c and 2d with the most recessed part of the recess 14 as shown in Figure 5. If not, side core 2c, 2d'r arrow C,
Cannot pull out in direction D.

If the abutment surface 5' is set to be aligned with the most concave portion of the recess 14 as shown in this figure, the sprue 9' and sprue lock 10' cannot be provided on this abutment surface.

The reason for this is that when attempting to provide the sprue 9' on the abutment surface 5' as shown by the reference line, the sprue γ is located at the recess 14 of the product.
ni: Because it has a penetrating shape.

If the sprue cannot be provided on the abutment surface of the side core due to the above-mentioned circumstances, the method of setting the sprue position according to the prior art is as follows.

a) A method in which the sprue lock is separated from the side core and provided in the longitudinal direction of the side core.

If this method is used, the entire mold becomes large and is uneconomical.

b) A method of installing it in a location other than the abutment surface, close to the side core.

If this method is used, the sprue cannot be automatically pulled out due to the sprue lock.

The present invention was developed in view of the above circumstances, and the sprue is provided at right angles to the longitudinal direction of the side core so as not to make the entire mold thicker. Moreover, the sprue is automatically pulled out as the mold is opened. The purpose of this invention is to provide a sprue lock mechanism that is in close contact with the side core and can automatically separate the sprue lock from the side core as the mold opens.

In order to achieve the above object, the present invention provides a sprue lock at a position in contact with the side core at or near the contact area between the sprue and the side core, and a side surface of the sprue lock that extends in the opening direction of the mold. By attaching a shaped taper, when the mold is opened, the side core engages with the sprue lock to open the mold, and the sprue is pulled out through the sprue lock.

Next, an embodiment of the present invention will be described with reference to FIG.

This example is a mold made for molding a product with a missing shape.

That is, it has a rectangular tubular shape as a whole as shown in FIG. 7, has an opening 15 near the center of the top surface, and a bar 16 is provided slightly inside the opening 15. Similar to the example shown in FIG. 5, this mold is made for plastic injection molding of a product whose shape makes it impossible to extract the side core unless a side core abutting surface is provided in contact with the bar 16.

The fixed side mounting plate 1', side block 4', inclined bar 6.6', sprue bush 7', sprue 9t and movable die plate 12' are shown with the same drawing reference numbers as in FIG. It is a member that is the same as or similar to a component of a mold in the prior art.

Side core 17a. The four gaps E, F, G, and H formed between the mold plate 17b and the fixed mold plate 18 are spaces for injecting and injecting molten plastic, and are shown in cross sections e and f+ in FIG. 7, respectively. This is the mold part that forms the part corresponding to g r h.

The sprue bush 7' of this embodiment is provided in close contact with the surface of the side core 17a on the fixed mold plate 18 side.

A sprue lock 19 according to the present invention is provided at a position where the sprue 9' formed in the hole of the sprue bush 7' contacts the upper surface of the side core 17H.

This sprue lock 19''f: A cutting block 20 is provided between the space to be formed and the gap E to block the sprue lock 19 and the gap E.

A runner (indicated by reference line 21) communicates between the lower end of the sprue 9' and the gap E.

The above sprue 9', sprue lock 19 and runner 21
The three-dimensional relationship is as shown in FIG. 8, where the molten plastic injected from above the sprue 9' in the direction of the arrow J fills the space corresponding to the sprue lock 19 and flows inside the runner 21 in the direction of the arrow. and flows into the space forming the product body 22.

A side surface 19a of the sprue lock 19 is provided with a taper that extends in the mold opening direction.

Since the mold opening direction (arrow B) of this embodiment is downward in this figure, the side surface 19a of the sprue lock 19 is tapered in the downward opening direction.

Since this embodiment is constructed as described above, molten plastic is injected in the state shown in FIG. 6, and the gap E,
The holes in F, G, H, Z and sprue bushings 7' are filled with molten plastic, and after the molten plastic solidifies, moving the movable mold plate 12' in the mold opening direction (arrow B) will remove the missing parts. It works like this.

Inside, without moving the movable mold plate 12', attach the fixed side mounting plate 1'.
and a fixed mold plate 18 and a cutting block 20 fixed thereto.
, Inclined bars 6', 6', etc. upward (arrow B//
), it has the same effect as a vacancy.

When the movable mold plate 12' descends in the mold opening direction (arrow B),
The side cores 17a, 17b are lowered together with the movable mold plate 12', and at this time the inclined bar 6' is lowered.

6' and descend while separating from each other in the left-right direction (arrows C and D).

(a) Along with the above movement, the side core 17a separates from the sprue bush 7'.

At this time, since the sprue lock 19 is engaged with the side core 17a by the tapered portion 19a on the side surface, it descends together with the side core 17a.

Since this sprue lock 19 is integrally formed with the sprue 9', as the sprue lock 19 lowers, the sprue 9'
' is pulled out from the sprue bush 7'.

(b) Simultaneously with the above action, the side core 17a is guided by the inclined bar 6' and moved to the left (in the direction of arrow C).
The engagement with a is released within a short period of time.

Therefore, the action of the side core 17a pulling out the sprue 9' from the pushbutton 7' via the sprue lock 19 is as follows.
1) Finish pulling out the sprue 9' from inside the sprue pusher 7)
It does not continue, but disappears immediately after the sprue 9' is peeled off from the inner surface of the sprue bush 7'.

As mentioned above, when the sprue 9' is peeled off from the inner surface of the sprue bushing 7', the sprue 9' is connected to the molded product 22 via the runner 21 (see Figure 8), so the molded product is removed as the mold opens. It is taken out together with.

As explained above, in the case where a sprue is provided closely to the side core of a mold, a sprue lock is provided at a position in contact with the side core at or near the contact area between the sprue and the side core, and the sprue lock is By adding a taper to the side of the mold that expands in the opening direction of the mold,
When the mold is opened, the side core pulls out the sprue through the sprue lock and peels it off in the "direction," and immediately after that, the sprue lock automatically separates from the side core.
Dogs are contributing to the automation of mold opening operations in plastic injection molding.

Furthermore, according to the present invention, the sprues can be provided perpendicularly to the longitudinal direction of the side cores, so the entire mold is compact and economical.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a mold commonly used in the past, Figure 2
The figure is a perspective view of the sprue area made by the above mold,
Fig. 3 is a plan view of the same, Fig. 4 is a perspective view showing an example of a product to be plastic molded, Fig. 5 is a sectional view showing a part of a mold for molding the above product, and Fig. 6 is a book Sectional view of a mold equipped with a sprue lock mechanism according to an embodiment of the invention, No. 7
The figure is a partially cutaway perspective view of a plastic molded product made with the above mold, and FIG. 8 is a perspective view of the same molded product with a sprue, a sprue lock, and a runner integrally formed therein. 1, 1'--Fixed side mounting plate, 2 a t 2 b
r 2 Cr2d, 17a, 17b... side core,
3, 18... Fixed mold plate, 4, 4'... Locking lock, 5, 5'... Abutment surface, 6, 6'... Inclined bar, ? , 7'... Sprubutush 8...
・Sprubutsu hole, 9°9'...Sprue, 10.
DESCRIPTION OF SYMBOLS 10', 19... Sprue lock, 19a... Side surface of sprue lock with chihara attached, 11... Abutment block, 12, 12'... Movable template, 13... Product, 1
4... recess, 15... opening, 16... bar, 2
0...Eating block, 21...Runner, 22...
Product body.

Claims (1)

[Scope of utility model registration request] For molds in which a sprue is provided closely to the side core, a sprue lock is provided at the contact area between the sprue and the side core, or at a position in contact with the side core in the vicinity, and a sprue lock is provided on the side of the sprue lock. A sprue lock mechanism in close contact with a side core, characterized in that the side core pulls out the sprue via the sprue lock when the mold is opened by adding a taper that spreads in the opening direction.