JPH034500Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a three-plate molding die that allows the molded product to be easily changed by replacing the nested mold, and is particularly applicable to changes in the molded product. This invention relates to a molding die that allows the gate position and runner lock position to be easily changed.

(Prior art) In this type of conventional three-plate molding mold,
The runner lock pin is fixedly disposed at one location at or near the extension of the gate of one nested mold, and is adapted to lock the runner branch.

(Problems to be solved by the invention) However, the above molding die has the following problems.

In other words, when molding various molded products, the nested mold is replaced each time, but the gate position of the nested mold cavity can be changed depending on the shape of the molded product, for example by adopting a side gate. It is normal for these to differ in various ways. Even in this case, the runner must always pass through the lock pin position in order to obtain the lock function of the lock pin. However, if the lock pin is fixedly provided at one location as in the prior art, the runner that reaches the gate via the lock pin becomes long depending on the gate position. Therefore, there are problems in that not only are the runner branches wastefully ejected, but the gate position is far from the runner lock pin, making it difficult to cut the gate and making it difficult to remove the runner branches.

Therefore, in the past, it was not possible to significantly change the gate position. In other words, with conventional products, the gate position and runner lock pin position are almost limited, making it difficult to mold products with different gate positions, such as direct gate molded products and side gate molded products. There was a problem that there was little freedom in mold design.

Therefore, this invention was devised to solve the above problems, and its purpose is to be able to deal with nested molds with various gate positions, and to greatly improve the degree of freedom in mold design. To provide molding molds.

(Summary of the invention) The present invention has the following configuration in order to solve the above problems.

That is, the molded product cavity is formed by a nested mold inserted into a movable mold base and a fixed mold plate.
In a plate-type molding die, a runner stripper plate is provided which can be freely moved into and separated from a fixed mold base by a predetermined stroke, and the fixed mold plate which can be moved by a predetermined stroke from and separated from the runner stripper plate, A plurality of runner lock pins are erected at appropriate intervals on the fixed mold base portion corresponding to the back surface of the fixed nesting mold inserted into the fixed mold plate, and the runner lock pins are provided on the runner stripper plate. A through hole into which the lock pin slides is provided, the length of the runner lock pin is set to such a size that the tip does not protrude from the surface of the runner stripper plate when the mold is closed, and the runner stripper is inserted into the back of the fixed insert mold. A runner groove connecting a sprue hole provided in the plate and an appropriately selected runner lock pin from among the runner lock pins, and a runner hole communicating the runner groove and the molded product cavity are formed. do.

(Function) In the present invention, a plurality of runner lock pins are provided corresponding to the fixed nesting type, so a runner hole is provided on the back side of the fixed nesting type to communicate the sprue hole and the cavity, and the runner hole is used as a gate. By simply providing a runner groove that connects to an appropriate runner lock pin near the position, a runner suitable for various fixed insert molds with different gate positions can be formed.

(Embodiment) A preferred embodiment embodying the present invention will be described in detail below with reference to the accompanying drawings.

In FIG. 1, 10 is a fixed type, and 11 is a movable type. The fixed mold 10 includes a fixed base 13 fixed to a fixed platen 12, a runner stripper plate 15 connected to the fixed base 13 by a limit bolt 14 so as to be separable by a predetermined stroke, and a runner stripper plate 15 that can be separated by a predetermined stroke. A fixed mold plate 17 is connected to the par plate 15 by a restriction pin 16 so as to be able to move into and out of a predetermined stroke. The fixed mold plate 17 is urged away from the runner stripper plate 15 by a spring 18.

Further, a fixed insert mold 20 is detachably fixed to the fitting hole 19 of the fixed mold plate 17 by suitable fixing means.

The movable mold 11 includes a movable base 22 fixed to a movable platen 21 that is moved toward and away from the fixed mold 10 by an appropriate hydraulic cylinder (not shown).
Further, the stroke of the movable base 22 is limited by a limiting pin 34.

A movable nesting mold 24 is removably fixed to the fitting hole 23 of the movable mold base 22 by suitable fixing means.

The fixed nesting mold 20 and the movable nesting mold 24 define a predetermined cavity 25 when the molds are clamped.

Reference numeral 26 denotes a projecting pin, which projects the molded product attached to the movable nesting mold 24 by a known mechanism.

A nozzle 27 passes through a nozzle entry hole 28 provided at the center of the stationary platen 12 and stationary base 13 and touches the runner stripper plate 15. 29 is a sprue hole provided in the runner stripper plate 15.

On the fixed base 13, twenty runner lock pins 30 having undercut portions at their tips are erected at appropriate intervals around the nozzle entry hole 28, as shown in FIG. The runner lock pin 30 slides into a through hole 31 formed in the runner stripper plate 15 so that it can move forward and backward. Further, its length is set so that the tip does not protrude from the surface of the runner stripper plate 15 when the mold is closed (FIG. 2).

A runner hole 32 that communicates the sprue hole 29 and the cavity 25 is provided on the back surface of the fixed insert mold 20. Also, a runner groove 3 connecting the runner hole 32 and two runner lock pins 30 in the vicinity thereof.
3 is engraved.

In this invention, which runner lock pin 3
Whether 0 is used or not is appropriately selected depending on the gate position of the fixed nested mold 20. In this case, one or two runner lock pins 30 closest to the gate position will be used, but a fixed insert with a runner groove 33 extending from the runner hole 32 in the direction of the predetermined runner lock pin 30 will be used. child type 2
All you have to do is prepare 0.

Next, the forming operation will be explained.

When the mold is closed and the molten resin is injected from the nozzle 27, the molten resin flows through the sprue hole 29 and the runner hole 32.
It is injected into the cavity 25 through.

When the mold is opened after cooling, since the fixed mold plate 17 is biased by the spring 18, the space between the fixed mold plate 17 and the runner stripper plate 15 is first opened. Runner branch has runner lock pin 30
Since it is held by the undercut portion of the molded product, it is cut from the molded product at the gate portion and remains on the runner stripper plate 15 side.

When the mold is further opened, the fixing plate 17 is fixed to the limiting pin 1.
6, the space between the movable mold base 22 and the fixed mold plate 17 is now opened, and the molded product is attached to the movable nesting mold 24 and exposed. Here, the ejecting pin 26 is ejected and the molded product is taken out.

The runner branch is regulated by the restriction pin 34, the restriction pin 16, and the restriction bolt 14, and the space between the runner stripper plate 16 and the fixed base 13 is opened, so that the runner stripper plate 15
The runner lock pin 30 is pushed and dropped from the tip of the runner lock pin 30.

In the above embodiment, an example of a nested type of direct gate is shown, but the present invention can be similarly applied to a case where a nested type of side gate is used. In this case, a runner hole is drilled from the back of the stationary insert mold, a runner groove is carved to connect the runner hole and the sprue hole, and a runner groove is also formed on an appropriate runner lock pin near the runner hole. Just extend it.

(Effect of the invention) As described above, in the present invention, multiple runner lock pins are provided, so it is only necessary to extend the runner groove on the nearby runner lock pin depending on the position of the gate of the fixed nesting type. Using the mold base, various nested molds with different gate positions can be used interchangeably. Moreover, since it is only necessary to select the most suitable runner lock pin according to the gate position, there is no problem with the gate becoming difficult to cut or preventing the runner from leaving the gate. In addition, the degree of freedom in mold design increases, and many molded products can be molded by replacing nested molds in the same mold, which reduces molding costs, mold costs, and management costs. The benefits are enormous.

[Brief explanation of the drawing]

The figures show preferred embodiments of the present invention. Figure 1 is a sectional view of the mold when it is opened, Figure 2 is a sectional view of the mold when it is closed and resin is injected, and Figure 3 is a runner stripper plate. shows a front view. 10... Fixed type, 11... Movable type, 12... Fixed plate, 13... Fixed type base, 14... Limiting bolt, 15... Runner stripper plate, 1
6... Limiting pin, 17... Fixed template, 18... Spring, 19... Fitting hole, 20... Fixed nesting mold, 21... Movable plate, 22... Movable base, 2
3... Fitting hole, 24... Movable nesting mold, 25... Cavity, 26... Projection pin, 27... Nozzle,
28... Entry hole, 29... Sprue hole, 30... Runner lock pin, 31... Through hole, 32... Runner hole, 33... Runner groove, 34... Limiting pin.

Claims (1)

[Scope of Claim for Utility Model Registration] In a three-plate molding mold in which a molded product cavity is formed by a nested mold inserted into a movable mold base and a fixed mold plate, a predetermined stroke with respect to the fixed mold base A runner stripper plate that can be freely moved toward and away from the runner stripper plate, and the fixed mold plate that can be moved toward and away from the runner stripper plate by a predetermined stroke are provided, and the fixed mold plate corresponds to the back surface of the fixed insert mold inserted into the fixed mold plate. A plurality of runner lock pins are erected on the fixed base part at appropriate intervals, a through hole is provided in the runner stripper plate into which the runner lock pins slide, and a length of the runner lock pins is provided. is set to such a size that its tip does not protrude from the surface of the runner stripper plate when the mold is closed, and the sprue hole provided in the runner stripper plate and the runner lock pin are placed on the back of the fixed nesting mold as appropriate. A molding die characterized in that a runner groove connecting selected runner lock pins and a runner hole communicating the runner groove with a molded product cavity are formed.