JPH05205B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an injection mold device for molding synthetic resin screw caps, and more specifically, its purpose is to significantly reduce the cost required for the mold device. It is something to do.

Mold equipment for injection molding is known to be extremely expensive, but mold equipment for screw cap molding in particular requires rotation of one of the molds, the core, to release the molded product. It has to be driven, which makes the structure complex and expensive.

In addition, since screw caps are small in size, they are generally made in large numbers using one molding device, and the molding device is also manufactured in such a configuration, making the structure that much more complex. Furthermore, as is well known, this type of synthetic resin screw cap always has different shapes and dimensions depending on the type of bottle to be assembled and the type of contents stored in this bottle. Since the screw caps are different from each other, it is necessary to manufacture a special mold device for each screw cap, and the cost required for the mold device is enormous.

Furthermore, even if the mold equipment is for molding small molded products such as screw caps, the overall size of the equipment will never be small due to its relationship with the injection molding machine, and this will result in a large number of molds being used. Storing and storing the equipment required a huge amount of space and a lot of effort.

The present invention was devised to solve the above-mentioned drawbacks and problems in the conventional example, and in this type of injection molding mold device, it is necessary to follow the difference in shape of the screw cap to be molded. What does not happen is mainly the cavity and core,
Focusing on the fact that the combinations of various plates and various pins that cause each plate to perform predetermined operations are common regardless of the shape of the screw cap to be molded, we developed a mold device. It is divided into a part consisting of various plates and pins, and a part having a cavity and core that form the mold space for the molded product, and the two parts can be used in an appropriate combination. It is.

An embodiment of the present invention will be described below with reference to the drawings.

The mold device for injection molding of synthetic resin screw caps according to the present invention is constructed by stacking various plates in order, and includes a plate body 1 in which a plurality of assembly cavities 21 having the same shape and dimensions are formed, and It is composed of a mold body 22 for molding a screw cap that is fitted and assembled into the mounting cavity 21, and the mold body 22 includes a cavity 23 that is assembled to the cavity plate 4 of the plate body 1, and a mold body 22 that is assembled into the cavity 21. A core metal 24 having a mold surface portion at its tip that combines with the cavity 23 to form a mold cavity, at least one stripper bush 25, which is fixedly assembled to the core metal 24 and receives rotational force. and an outer cylinder 28 for rotatably assembling and fixing the core metal 24 to the core plate 6 of the plate body 1. are screwed together with screws of the same pitch as the screws of the molded screw cap.

In the illustrated embodiment, the plate body 1 immovably assembles and fixes the nozzle touch 9 against which the nozzle of the injection machine is pressed, and forms part of the assembly of the mold device according to the invention to the injection molding machine. Top plate 2 and runner plate 3 forming a runner
, a cavity plate 4 to which the cavity 23 of the mold body 22 is assembled and fixed, a stripper plate 5 to which the stripper bush 25 of the mold body 22 is assembled and fixed, and an outer cylinder 28 of the mold body 22. The core plate 6 is assembled and fixed, a core retainer plate 7, and a back plate 8, which is the other part to be assembled into the injection molding machine of the apparatus of the present invention, are stacked one on top of the other in this order.

The configuration of the above-mentioned plate body 1 is almost the same as the combination of various plates in a conventional mold device, and the assembly of various pins is also the same as in the conventional mold device.

That is, a guide pin 15 is attached to the core retainer plate 7 and back plate 8 which are fixed to each other, and the cavity plate 4, stripper plate 5 and core plate 6 are connected by this guide pin 15. , accurately guides the movement direction and posture during mold opening and mold closing operations (hereinafter simply referred to as opening/closing operations).

Limiting pin 14 fixed to top plate 2
is for setting the mold opening limit of the cavity plate 4, and the runner strip pin 13 fixed to the runner plate 3 uses the mold opening movement of the cavity plate 4 to open the runner plate 3.
The mold is opened and moved.

The stripper plate stop pin 12 fixed to the core plate 6 sets the separation movement limit of the stripper plate 5 from the core plate 6, and the runner plate stop pin 11 fixed to the runner plate 3 It sets the separation movement limit of the runner plate 3 from the top plate 2, and
When the mold is opened, the runner pin 10 fixed to the
This is to ensure that the runner R adheres to the runner plate 3 side.

In this way, the plate body 1 has exactly the same structure as the combination structure of various plates and pins in conventional mold equipment, and although not shown, it has ejector pins, tie bars, etc. Needless to say, there are.

However, the plate body 1 in the mold apparatus according to the present invention has a plurality of assemblies of the same shape and size across the cavity plate 4, stripper plate 5, core plate 6, and core retainer plate 7. A void space 21 is formed.

Since each assembly space 21 is a part where the mold body 22 is assembled and fixed, the formation position thereof is set so as to be located approximately at the same distance from the nozzle touch 9 as shown in FIG. .

The number of assembly cavities 21 is not particularly limited, and in the embodiment shown in FIG. 1, four are formed, which is an embodiment of a four-cavity mold device.

The mold body 22 inserted and assembled into each assembly cavity 21 is a part for directly molding the molded product S, which is a screw cap, and in the illustrated embodiment, a cavity 23 forming one mold surface. , a core mandrel 24 having a threaded surface, which is the other mold surface, formed on the tip end thereof, first and second stripper bushes 25 and 26, and the rotational force from the outside is transferred to the core mandrel 24. The transmission gear 30 that transmits the information to the core metal 2
4 and an outer cylinder 28 which is rotatably assembled and fixed to the plate body 1.

In the mold body 22 having such a structure, the cavity 23 is independently assembled and fixed to the assembly step 4' of the cavity plate 4 through its assembly flange, and is also attached to the first strip. The part bush 25 is also individually assembled and fixed to the mounting step 5' of the stripper plate 5 by its mounting flange.

The parts other than the cavity 23 and the first stripper bush 25 are assembled and handled as one body, as shown in FIG.

That is, the transmission gear 30 is fixed immovably to the core metal 24 which has a screw-shaped end portion as its main body, and the core metal 24 itself has a cylindrical outer tube 28. A second stripper bush 26 is fixed to the tip of the outer cylinder 28.

Then, this assembly is assembled and fixed to the assembly step 6' of the core plate 6 by an assembly flange attached to the outer cylinder 28.

In the case of the illustrated embodiment, a lead screw 27 is formed on the inner circumferential surface of the outer cylinder 28 with a pitch equal to the thread groove formed in the molded product S. A lead screw body 29, which is screwed into the lead screw 27, is immovably assembled and fixed to the metal 24.

That is, when the core mandrel 24 and the outer cylinder 28 are relatively rotationally displaced, the lead screw 27, that is, the screw pitch of the molded product S, is displaced in the mold opening direction, which is the axial direction of the core mandrel 24. .

In addition, the cooling mechanism for the molded product S, that is, the cooling passage 34 formed in the cavity 23, and the cooling pipe body 32 and cooling passage 33 formed in the core metal 24, are provided when the mold body 22 is assembled with the plate body 1. By being assembled into the mounting space 21, it forms a passage and is connected to a cooling fluid supply device (not shown).

Furthermore, various means can be considered as means for transmitting rotational force to the transmission gear 30, and the configuration is not limited. In the case of the illustrated embodiment, the plate body 1 is A rotating gear 16 that is rotationally driven by opening and closing operations is attached, and this rotating gear 16 is meshed with a transmission gear 30, thereby rotationally driving the transmission gear 30, that is, the core metal 24.

Note that a reservoir 19 formed in the back plate 8 as a part of the assembly space 21 allows the cooling fluid to
It provides a part of the passage leading from the supply passage 18 into the cooling tube 32, and also provides a space for the retreating movement of the core metal 24.

Since the mold device according to the present invention has the above-described configuration, first, as shown in FIG. The combination is inserted into the assembly space 21 of the combination of the core plate 6, core retainer plate 7, and back plate 8 of the plate body 1 in the opened state, and the outer cylinder 28 is inserted. The assembly flange portion is fixed to the assembly step portion 6' of the core plate 6 with bolts or the like.

Similarly, the first stripper bush 25 is attached to the stripper plate 5 and the cavity 23
By assembling and fixing these to the cavity plate 4, the mold body 22 is assembled and fixed to the plate body.

Further, the molding operation of the mold device according to the present invention is exactly the same as the molding operation of the conventional mold device, and to briefly explain this, when the mold opening operation of the plate body 1 starts, this mold opening operation starts. Yotsute core core metal 2
4 rotates, it moves to the right in FIG. 7 due to the action of the lead screw 27 and the lead screw body 29, and comes out of the molded product S. I'm moving to get out.

When the core metal 24 is rotating, the molded product S
However, the second stripper bush 26 holds the molded product S immovably so that it does not rotate together with the core metal 24.

When the mold opening operation of the back plate 8 (movement to the right in FIG. 7) progresses and the core metal 24 reaches the position where it is completely removed from the molded product S, the ejector pin (not shown) This action prevents the stripper plate 5 from moving together with the back plate 8 in the mold opening direction, so that the stripper plate 5 is moved leftward relative to the core plate 6. This causes the first stripper bush 2 to move.
5 passes the molded product S to the second stripper bush 2.
6, detachment of the molded article S is achieved.

In this manner, the mold device according to the present invention uses a large number of mold bodies 22, each of which has a standardized shape and size of the part assembled to the plate body 1, assembled to a single plate body 1. Therefore, when molding the molded product S as a new screw cap, only the mold body 22 needs to be newly manufactured, and the cost required for manufacturing the plate body 1 portion can be reduced.

Furthermore, when changing the molded product S to be molded, only the compact and lightweight mold body 22 needs to be handled, making the mold exchange operation simple and safe.

Furthermore, since the assembly of each mold body 22 to the plate body 1 is achieved individually, it is possible to freely set combinations of different molded products S to be cut in large numbers, and Therefore, it is possible to mold only the required molded product S in an accurate quantity according to the request.

Furthermore, since each mold body 22 is much smaller in size than the entire mold apparatus, it does not require a large space for handling or storing it.

Since the pitch of the threaded grooves molded into the molded product S is set by the lead screw 27 of each mold body 22, the molded products S with different threaded groove pitches can be molded together with a single mold device. I can do it.

As is clear from the above description, the injection molding mold apparatus according to the present invention can significantly reduce costs in terms of mold manufacturing, handling, maintenance and management of the mold, and It exhibits many excellent effects, such as being able to mold a precise number of products without waste, and also being able to mold products with different structures in free combinations.

[Brief explanation of the drawing]

FIG. 1 is a side view of the mold apparatus according to the present invention as seen from the injection machine side. FIG. 2 is a longitudinal sectional view of the device of the present invention, excluding the rotating gear. FIG. 3 is a longitudinal sectional view showing the rotating gear of the device of the present invention. Fourth
The figure is a longitudinal sectional view of only the plate body of the device of the present invention. FIG. 5 is a front view of only the mold body of the device of the present invention. FIG. 6 is a partially exploded view for explaining the assembly of the device of the present invention. FIG. 7 is a longitudinal cross-sectional view showing the main part of the present invention in a mold-closed state and a mold-opened state, respectively, in half section. Explanation of symbols: 1... Plate body, 2... Top plate, 3... Runner plate, 4... Cavity plate, 5... Stripper plate,
6... Core plate, 8... Back plate, 1
6... Rotating gear, 21... Assembly space, 22...
Mold body, 23... Cavity, 24... Core core metal,
25...First stripper bush, 28...
Outer cylinder, 30...transmission gear, S...molded product, R...
runner.

Claims (1)

[Claims] 1. A plate body made up of various plates stacked one on top of the other and having a plurality of assembly cavities of the same shape and size formed therein, and a mold body for molding a screw cap to be fitted and assembled into the assembly cavities. The mold body is composed of a cavity assembled to the cavity plate of the plate body, a core mandrel having a mold surface portion at its tip that combines with the cavity to form a mold cavity; at least one stripper bush; a transmission gear that is fixedly assembled to the core metal and receives rotational force; and an outer cylinder that rotatably assembles and fixes the core metal to the core plate of the plate body. An injection mold device comprising: the outer cylinder and the core metal are screwed together with screws having the same pitch as the screws of the screw cap to be molded.