JPH10175221A - Mold opening restriction device for resin molding - Google Patents

Abstract

(57) [Summary] [Problem] To provide a durable, stable regulating force for a long period of time without abrasion, to minimize the generation of dirt, and to assure metal by being installed outside the mold. A mold opening restriction device capable of restricting the opening of a mold and capable of arbitrarily controlling the opening of the mold. SOLUTION: A fulcrum part 2, a cam 3 provided on the fulcrum part so as to be swingable and having a key part 7, a cam inoperative part 9, and a cam operating part 8, a post 5 engaging with the key part, a recording cam A cam follower 4 which engages with the operating portion;
And a cam follower 4 are installed on the outer peripheral side surface of the separate template 12, and the template and the post 5 provided with the fulcrum 2 are provided.
The opening of the template provided with is controlled by a cam mechanism.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold opening regulating device for regulating the opening of a mold in a resin molding machine such as an injection molding machine.

[0002]

2. Description of the Related Art Heretofore, when a mold is opened in injection molding or the like, the opening of the mold plate is regulated by using mold regulating parts so that the operation of the mold opening is performed in order and accurately. As a conventional mold regulating component, for example, a tapered bolt penetrating the inside of a resin cylindrical bush is tightened into a movable mold plate, and the resin cylindrical bush is positioned in a hole formed in a fixed mold plate, There is known a method in which a resin cylindrical bush is compressed by tightening a taper bolt to adjust a frictional force with an inner wall of a hole, thereby adjusting a pulling force at the time of opening the mold.

[0003]

However, the above-mentioned conventional mold regulating parts regulate only the frictional force between the resin cylindrical bush and the inner surface of the cylindrical hole of the fixed mold plate. There was a problem that wear was severe and stable regulation force could not be maintained for a long time. In addition, it was difficult to obtain a certain regulating force because of the inner surface roughness of the hole of the fixed mold plate. Furthermore, since the above-mentioned mold regulating component is installed inside the mold, there has been a problem that the resin that has become worn and powdered may become dirty and adhere to the product.
In addition, since the conventional mold restricting parts are for restricting the opening by giving a resistance force from the beginning of the mold opening by a frictional force of a resin cylindrical bush or the like between the molds, for example, it is free to an arbitrary interval. However, it is impossible to control the opening freely, for example, by regulating only a specific section.

An object of the present invention is to solve the above-mentioned drawbacks of the conventional mold opening restricting device. Instead of using a conventional resin cylindrical bush, there is no wear, durability and long-term stability. The regulating force is obtained, the generation of dirt due to the mold can be minimized, and the mold opening can be reliably controlled by installing outside the mold, and the regulation of the opening can be arbitrarily controlled. It is an object to obtain a simple mold opening restriction device.

[0005]

According to the present invention, there is provided a resin molding die opening restricting device for solving the above-mentioned problems, which is provided at a fulcrum, swingably provided at the fulcrum, a key portion, a cam inoperative portion, and A cam having a cam operating portion, a post engaging with the key portion, and a cam follower engaging with the cam operating portion, wherein the fulcrum portion, the post and the cam follower are respectively installed on the outer peripheral side of a separate template, The opening of the template provided with the fulcrum and the template provided with the post is controlled by the cam and the cam follower.

The key portion can be formed in an arbitrary shape in accordance with the opening of the mold. For example, the key portion can be formed as a lock groove in which the post fits, or as a stepped step wall. The positional relationship can be selected at any position according to the mold opening. For example, if the key portion and the post are provided in a completely engaged state with the post being closed, the fulcrum will be initially set at the start of mold opening. The provided template and the template provided with the post are completely integrated and do not open therebetween, and when the cam follower reaches the cam operating portion, the engagement between the key portion and the post is released, and the fulcrum is supported. An opening between the template provided with the part and the template provided with the post can be started.

In addition, by providing a predetermined amount of clearance between the post and the key portion in a state where the mold is closed, the post can be displaced, so that the fulcrum portion is provided at the start of opening of the mold. The template and the post provided with the fulcrum are provided while the gap between the plate and the template provided with the post is opened by the clearance, and the cam follower passes through the inactive portion of the cam. The template is displaced integrally in that state, the cam follower is engaged with the cam operating portion to release the engagement between the post and the key portion, and the template provided with the fulcrum portion and the post are provided. The opened template can be controlled to open further.

The number of the key portion, the cam operating portion and the cam non-operating portion is not necessarily limited to one, and it is possible to provide a plurality of each according to a desired mold opening state. Can control.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. In the present embodiment, a case will be described in which the present invention is applied to a mold apparatus 10 having a mold main part 11 shown in FIG. 3 for injection-molding a cap 30 with a pull ring as shown in FIG.

[0010] The mold opening restriction device of the present invention comprises a mold device 1.
0, that is, mold plates 12a-1 for opening and closing the mold.
It is attached to the outer peripheral surface of a mold plate made of 2n, and includes a fulcrum 2, a cam 3, a cam follower 4, and a post 5, as shown in FIG. The fulcrum 2 is fixed to a specific template on the movable side, and the base end of the cam is pivotally attached to the fulcrum 2 so as to be swingable.

Although not shown, the cam 3 is appropriately biased by a spring or the like so as to maintain the horizontal state shown in FIG. The cam 3 controls opening of the mold according to the shape thereof, and the shape can be arbitrarily formed in accordance with the shape of the injection molded product. In the present embodiment, there is provided a lock groove 7 as a key portion with which the post 5 provided on the outer peripheral portion of the specific template is engaged. In this embodiment, the lock groove is larger than the diameter of the post 5 in the present embodiment. It is formed so as to have a predetermined clearance in the displacement direction of the template when fitted. Therefore, even when the post 5 is fitted in the lock groove, the template provided with the fulcrum 2 by the clearance can be displaced without load, and the post is engaged with the key wall surface of the lock groove to lock the post. Thus, the template having the fulcrum 2 and the template having the post 5 are integrally displaced.

The cam 3 has a convex surface 8 as a cam operating portion at a predetermined position as shown in the figure. When the cam follower 4 engages with the convex surface 8, the cam swings counterclockwise in FIG. As a result, the post 5 is disengaged from the lock groove 7 as shown in FIG. 2D, and the template having the fulcrum portion 2 is again in a no-load state, and the template having the post 5 and the fulcrum The templates having the portions 2 are in a relationship where they can be freely displaced from each other. Further, the template having the cam follower 4 is on the fixed side with respect to the parting line, and the cam follower 4 can be freely displaced with respect to the cam 3 when the mold is opened. An inactive portion 9 is formed between the lock groove 7 and the convex surface 8 of the cam, and the engagement between the post 5 and the lock groove can be maintained while the cam follower 4 passes through the inactive portion 9. .

Next, a description will be given of a case where the mold opening restricting device according to the present embodiment having the above-described structure is applied to the injection molding mold device shown in FIG. FIG. 3 shows a cross section of the mold main part 11 in the mold apparatus. Conventionally, in the injection molding of the cap 30 with a pull ring shown in FIG. 4, the gate portion is first pulled out when the mold is removed after molding. Since there is no backup of the copy, there is a disadvantage that the score 33 is easily cut. On the other hand, if the cooling core and the inner mold of the pouring cylinder are pulled out first, when the molded product is separated from the fixed mold, the pouring cylinder does not have a backup of the inner mold of the pouring cylinder. The holding force of the outer cylinder outer mold decreases, and the movable mold cannot hold the molded article due to the pulling of the molded article of the fixed mold and the movable mold, so that the disadvantage that the molded article remains in the fixed mold occurs.

In the present embodiment, in order to eliminate such a drawback, the cooling die is first pulled out, and then the inner cylinder 14 is withdrawn a distance s enough to maintain the support of the discharging cylinder 34. By pulling out the gate portion 20 in the state, the occurrence of score breakage is prevented, and the inner mold 14 is locked to the mold 15 until the movable mold and the fixed mold are completely separated from each other. By opening the mold with maintaining the movable mold and the fixed mold, it is possible to increase the holding force of the molded article by the movable mold when the movable mold and the fixed mold are separated.
The mold opening is controlled by the mold opening restriction device.

That is, in this embodiment, in the mold shown in FIG. 3, the fulcrum portion 2 is provided on the mold plate 12k for operating the inner mold 14 and the post 12 is provided on the mold plate 12i for operating the outer mold 15. 5 and a template 12g for operating the fixed mold
The cam follower 4 is provided. In the cam 3, the lock groove 7 is formed in such a size that the post 5 can still be displaced by the distance s with the post 5 fitted in the lock groove, and the convex surface is completely fixed type and movable type. Are formed in such a positional relationship that the cam follower 4 comes into contact with the cam follower after a predetermined distance from the cam follower. In FIG. 3, reference numeral 18 denotes an outer skirt wall type, and 19 denotes an inner skirt wall type.

The mold opening in the mold device formed as described above will be described with reference to the process charts of FIGS. The mold opening is shown in FIGS. 5 (a) to 5 (e) to FIGS.
It is performed in the order of (d). FIG. 5A shows a state immediately after the end of the injection molding and the opening of the mold, and FIG. 1 shows an outer peripheral portion of the mold apparatus in this state. In this state, the post 5 is fitted in the lock groove 7, but the post 5 and the engaging wall of the lock groove are in a non-locked state with a clearance, and the cam follower is also in contact with the inoperative portion 9 so that the load is not applied. It is in. When the mold starts to open, first the cooling core 13
Moves a predetermined distance away from the top wall 31 of the cap (FIG. 5).
(B)) Then, a cam 3 is provided between the template 12k and the template 12j.
When the post 5 is opened by the gap between the lock groove 7 and the post 5, that is, by the distance s, the post 5 is engaged with the engagement wall of the lock groove and is locked (FIGS. 5C and 2B). . Accordingly, the inner end of the ejection tube die 14 is stopped at a position where the tip is located between the outer periphery of the pull ring and the inner periphery of the ejection tube to support the ejection tube, and is locked in this state.

Further, between the template 12g and the template 12h,
That is, when the cam follower 4 is opened from the parting line as shown in FIGS. 5D to 5E, the cam follower 4 engages with the convex surface 8 and starts pushing up the cam (FIG. 2C). At this point, the movable mold and the fixed mold are separated from the parting line (FIG. 5 (d)), and the molded article is completely separated from the fixed mold as shown in FIG. 5 (e). Up to this point, the mold is opened while the movable mold is locked by the cam. Therefore, when the fixed mold and the movable mold are separated from each other, the dispensing cylinder is backed up by the dispensing cylinder inner mold, so that it is not deformed inward. It is possible to reliably hold and separate the cap on the movable side mold, overcoming the tension with the side mold (FIGS. 5D to 5E).

When the opening of the mold advances and the cam follower 4 completely pushes up the cam, the post 5 locked in the lock groove 7 of the cam is released as shown in FIG. 2D. As a result, the space between the mold plates 12j and 12k starts to open again, the inner mold 14 is completely pulled out of the pull ring, and the support of the ejector cylinder 14 is released (FIG. 6A). Therefore, the inside of the dispensing cylinder is easily deformed, and the dispensing cylinder outer mold 15 can be easily removed. In this state, the stripper 17 supports the cap and is displaced toward the fixed mold so that the molded cap is easily removed from the movable mold (FIG. 6).
(B)-(c)). When the stripper returns with the cap completely removed, the cap is completely released and discharged from the mold apparatus (FIG. 6).
(D)). Thereafter, when the mold is clamped, it returns to the original state shown in FIG.

The embodiment of the present invention has been described above.
The present invention is applicable not only to injection molding but also to a mold opening restriction device in compression molding or the like. The specific configuration is not limited to the above embodiment, and various design changes can be made within the scope of the technical idea. For example, in the above embodiment, the key portion is formed in the lock groove. However, a stepped wall may be formed in the cam side edge portion in a stepped manner so that the post engages. The key portion of the cam is not limited to one, and a plurality of key portions can be provided at predetermined intervals so that the mold opening can be gradually locked in accordance with the shape of the molded product. It is. In that case, a plurality of cam operating portions may be provided in accordance with the key portion. It goes without saying that the mold is not limited to the above-mentioned pull-tab cap molding, but can be applied to molds for various molded products.

[0020]

As described above, the mold opening restricting device of the present invention has less wear than conventional devices using a synthetic resin bush, and is durable and stable for a long period of time. You can gain power. In addition, since it is provided on the outer peripheral surface of the mold plate, even if it is worn, abrasion powder does not adhere to the molded product, and the molded product can be taken out satisfactorily without fear of soiling the molded product. Further, since the opening of the mold plate can be completely regulated by the lock mechanism, it is possible to prevent an excessive tension from being generated in the molded product when the mold is opened, and it is possible to effectively prevent the molded product from being damaged.

Further, in the present invention, the opening of the mold is regulated by the lock mechanism which is opened and closed by a cam provided on the outer peripheral surface of the mold plate. Can be regulated. Therefore, by changing the cam shape, for example, a certain template is freely opened up to a certain point in the mold opening process, locked and regulated after a certain point, or the regulation and release are repeated.
The mold opening can always be performed under optimum conditions according to the shape of the molded product.

[Brief description of the drawings]

FIG. 1 is a front view of a mold apparatus to which a resin mold opening restriction device according to an embodiment of the present invention is applied.

2 (a) to 2 (d) are explanatory views of the operation of the resin molding die opening restricting device according to the embodiment. FIG.

FIG. 3 is a sectional view of a main part of a mold of the mold apparatus shown in FIG. 1;

FIG. 4 is a cross-sectional view of a cap with a pull tab injection-molded by the mold.

5 (a) to 5 (e) are views for explaining a mold opening process in a main part of the mold of the mold apparatus shown in FIG.

6 (a) to 6 (d) are views for explaining a mold opening process in a main part of the mold of the mold apparatus continued from FIG.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 mold opening restricting device 2 fulcrum 3 cam 4 cam follower 5 post 7 lock groove (key portion) 8 convex surface (cam operating portion) 9 non-operating portion 10 mold device 12 (12a-
12n) Template 13 Cooling core 14 Injection cylinder inner mold 17 Stripper 30 Cap with pull ring 31 Top wall 32 Pull ring 33 Score

Claims (5)

[Claims] 1. A resin mold opening restriction device, comprising:
A fulcrum portion, a cam having a key portion, a cam inoperative portion, and a cam operating portion provided swingably at the fulcrum portion, a post engaging with the key portion, and a cam follower engaging with the cam operating portion. The fulcrum, the post, and the cam follower are respectively installed on the outer peripheral side surface of the separate template, and the opening of the template provided with the fulcrum and the template provided with the post is controlled by the cam and the cam follower. A device for restricting mold opening for resin molding, characterized in that: 2. The resin mold opening restriction device according to claim 1, wherein the key portion comprises a lock groove into which the post fits. 3. The resin mold opening restriction device according to claim 1, wherein the key portion is formed of a stepped step wall. 4. A mold plate having a predetermined clearance between the post and the key portion in a state in which the mold is closed, the post being displaceable, the template provided with the fulcrum portion, and the post being provided. In the meantime, the template is opened by the clearance at first, the cam follower is displaced integrally while the cam follower passes through the inoperative portion of the cam, and the cam follower engages with the cam operating portion to engage with the post. 4. The resin mold opening restriction according to claim 1, wherein the fulcrum, the post, and the cam follower are provided on the template in a positional relationship such that the engagement with the key is released and further opened. apparatus. 5. The resin mold opening restriction device according to claim 1, wherein a plurality of said key portions and a plurality of cam operation portions are provided.