KR20060024119A - Runer core pin for filling balance - Google Patents

Abstract

The present invention relates to a core filler for balanced filling of plastic injection molding molds for cold runners and hot runners, the object of which is each auxiliary runner by a runner core pin for guiding the flow of molten resin. Balanced filling of the molten resin supplied to the side, to provide a runner core pin for the plastic injection molding balanced filling that can prevent the defect of the product formed in a plurality of cavities in advance.

According to the present invention, the fixed side plate is mounted on the upper fixed side mounting plate, and the movable side plate is mounted on the lower movable side mounting plate, and the molten resin supplied through the sprue and vertical runner passes through the horizontal main runner. Ordinary plastic injection molds (for hot runners and cold runners), which are divided into two main runners extending to the left and right sides to reach both ends of the horizontal main runner and supply molten resin to a plurality of symmetrically installed cavity sides. In),

It is installed to slide in the longitudinal direction of the horizontal main runner, and configured as a slider-type core pin in which the curved end portion is inserted / removed to the center of both ends of the horizontal main runner in accordance with the opening and closing of the mold,

In addition, a balanced filling of plastic injection molding configured to form a fixed core pin having a curved end portion fixed to a central portion of both ends of the horizontal main runner so that evenly splitting of the molten resin supplied to the auxiliary runners formed on the left and right sides occurs. The technical gist of the runner core pin for the core is made.

Injection Mold, Angular Pin, Slider, Core Pin, Cold Runner, Hot Runner, Runner Manifold Plate

Description

Runner core pin for filling balance             

Figure 1a is a cross-sectional view of the closed state of the injection mold for cold runner to which the present invention is applied

Figure 1b is an exemplary cross-sectional view of the open state of the injection mold for cold runner to which the present invention is applied

2 is an enlarged view illustrating main parts of FIG. 1A;

Figure 3 is a perspective view showing the configuration of a plurality of cavity and runner in the injection mold for cold runner to which the present invention is applied

Figure 4 is a cross-sectional view of the injection mold for hot runner to which another embodiment of the present invention is applied

Figure 5 is a perspective view showing the configuration of a plurality of cavities and runners formed by the runner manifold plate of the injection mold for hot runner to which the present invention is applied

Figure 6 is a schematic diagram showing the flow of the molten resin at the branch point of the runner according to the present invention in comparison with the conventional

<Description of the symbols for the main parts of the drawings>

(11), (11-1): fixed side mounting plate (12), (12-1): fixed side plate

(13): movable side mounting plate (14), (14-1): movable side plate

(15,15-1): Upper eject plate (16,16-1): High eject plate

(17): space block (18), (18-1): eject pin

(19): Spuru (20,20-1): Vertical runner

(21,21-1): Horizontal main runner (22,22-1): Auxiliary runner

(22a): gate 25, (25-1): cavity

30: angular pin 35: slider

(35a): Inclined through hole (36), (36-1): Runner core pin

37: Stopper 40: Runner Manifold Edition

(41): hot bush (A, A-1): branch point

(P): Flow velocity of molten resin at inner corner of branch point

(P '): Flow velocity of molten resin at outer corner of branch point

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to runner core pins for cold runners and hot runners for balanced filling of plastic injection molds, and more particularly to run through runners having branches for injection molding a plurality of molded articles. The present invention relates to a runner core pin for balanced filling in plastic injection molding that allows the molten resin to be balanced in a plurality of cavities.

Usually, a mold used when manufacturing a molded article of a synthetic resin material is injected with a high temperature molten resin into a cavity configured inside thereof through a sprue and a runner configured on one side, thereby desired. It is a method of molding a molded product.

At this time, the runner refers to the length from the sprue to the gate inlet of the cavity forming the molded article, and is generally controlled only by the temperature of the mold and ejected together with the molded article. In addition to the temperature of the mold, the heat is applied separately so that the molten resin is always maintained at a constant temperature so that only the molded article in the cavity is classified as a hot runner.

In the general cold runner mold, a fixed side plate is formed at a lower end of the fixed side mounting plate, and a movable side plate which is in close contact with the fixed side plate to form a cavity of a molded article is installed on the lower side of the movable side mounting plate. The upper and lower sides of the movable side mounting plate are fixed with an eject pin for performing an ejection process for dropping molded products and runners after an injection process and a cooling process. The projected plate is spaced apart from the movable side plate by a space block (see FIG. 1).

In addition, the hot runner mold is typically installed to further include a hot manifold and a hot bush around the molten resin in the runner to maintain a constant temperature (see FIG. 4). )

In the mold having the above-described configuration, in particular, a mold forming a plurality of cavities, the molten resin introduced by the dead output by the external injection cylinder is introduced through the sprue and the vertical runner on one side, and then through the horizontal main runner. Molten resin is injected into each cavity through the auxiliary runners located left and right.

In general, the molten resin flowing in the runner is balanced by filling the molten resin that passes through the cross-sectional area in the runner due to the asymmetrical shearing speed and shear heating of the melt, which causes viscosity changes along the cross-sectional area and the longitudinal direction of the runner. This will not be done.

In particular, in the case described above, at the end point where the molten resin flowing in the horizontal main runner branches to the auxiliary runners located at the left and right sides, the molten resin flowing through the inner side P of the left and right branch points of the horizontal main runner is the outer part ( P ') is introduced at a higher speed than that of P') (see FIG. 6), which causes a change in viscosity of the molten resin branching to the left and right, so that a defective product is formed among the molded products in each cavity. There was a problem that occurred.

The present invention has been made to solve the above-mentioned conventional problems, the object of which is left in the horizontal main runner to perform a balanced supply into the plurality of cavities located on the left and right flow into the horizontal main runner The present invention provides a runner core pin for balanced filling of plastic injection molding, which is installed at an end of a branch.

The present invention to achieve the object as described above and to perform the problem for eliminating the conventional defects is fixed side plate is mounted on the fixed side mounting plate of the upper, movable side plate is mounted on the movable side mounting plate of the lower, The molten resin is supplied to the center of the fixed side plate through sprues and vertical runners, and the molten resin passes through the horizontal main runners to reach both ends of the horizontal main runners and extends the respective auxiliary runners extending left and right. In the plastic injection mold for cold runner to be supplied to the molten resin dividedly supplied through the symmetrically installed cavities,

An angular pin having a predetermined angle of inclination through the fixed side plate is installed at a lower end of the fixed side mounting plate; It is provided with an inclined through hole corresponding to accommodate the inclined angular pin, positioned between the fixed side plate and the movable side plate to be installed to slide in the longitudinal direction of the horizontal main runner on the movable side plate, runner on one side Constructing a slider having a core pin; According to the mold opening and closing, the curved front end of the runner core pin configured in the slider is inserted into and departed from the center of both ends of the horizontal main runner, so that the divided parts of the molten resin supplied to the auxiliary runners on the left and right sides are formed. It is done.

In addition, the fixed side plate is mounted on the upper fixed side mounting plate; A movable side plate is mounted on the movable side mounting plate at the bottom; A preheating device is provided in the section between the fixed side mounting plate and the fixed side mold plate, and molten resin is supplied through a sprue and a vertical runner at the center of the fixed side mounting plate, and the molten resin passes through a horizontal main runner. The runner manifold reaches both ends of the horizontal main runner and is supplied through a plurality of auxiliary runners extending to the left and right sides to supply molten resin to a plurality of cavity sides symmetrically formed by the fixed side plate and the movable side plate. In the plastic injection mold for hot runner having a fold plate,

A runner core pin formed at the center of both ends of the horizontal main runner formed on the runner manifold plate so as to protrude the curved front end thereof so as to have an even division of the molten resin supplied to the left and right auxiliary runners. It features.

In addition, the runner core pin is characterized in that the temperature can be adjusted.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Figures 1a and 1b is a cross-sectional illustration of the closed and open state of the injection mold for cold runner to which the present invention is applied, Figure 2 is an enlarged view of the main portion of Figure 1a, Figure 3 is a plurality of cavities applied to the injection mold for cold runner And showing a perspective view showing the configuration of the runner,

In constructing a common cold runner injection mold and a hot runner injection mold, the supply of molten resin is equally performed to a plurality of cavities 25 which are symmetrical with respect to the horizontal main runner 21. .

That is, the stationary side plate 12 is mounted on the upper fixed side mounting plate 11, and the movable side plate 14 is mounted on the lower movable side mounting plate 13, so that the stationary side plate 12 is closed. The molten resin is supplied to the center through the sprue 19 and the vertical runner 20, and the molten resin passes through the horizontal main runner 21 to reach both ends of the horizontal main runner 21, and to the left and right sides. In a conventional cold runner plastic injection mold, which is dividedly supplied through each of the auxiliary auxiliary runners 22 formed to be extended to supply molten resin to a plurality of symmetrically installed cavities 25,

An angular pin 30 is installed at the lower end of the fixed side mounting plate 11 to penetrate the fixed side plate 12 to form a predetermined slope.

In addition, the movable side plate 14 is installed to be slidable in the longitudinal direction of the horizontal main runner 21 on the movable side plate 14 so as to be located between the fixed side plate 12 and the movable side plate 14, the runner core pin on one side. The slider 35 provided with 36 is comprised.

At this time, the slider 35 has an inclined through hole 35a corresponding to the angular pin 30 at the same time as the mold is closed, and in accordance with the vertical movement of the angular pin 30 according to the opening and closing of the mold. An angular pin 30 inclined at a predetermined inclination angle is inserted and guided thereto so as to slide horizontally on the movable side plate 14.

In addition, a stopper 37 for limiting the movement of the slider 35 sliding in the horizontal direction is installed on one side of the movable side plate 14 by a separate fastening member.

The present invention is configured by the slide type runner core pin 36 is installed in the injection mold for cold runner as described above by the angular pin 30 is moved vertically accordingly while the mold is closed before supplying the molten resin The slider 35 moves horizontally on the movable side plate 14 so that the end of the core pin 36 fixed to the slider 35 in the closed state of the final mold is the branch point A of the horizontal main runner 21. ) Is inserted into the central portion of both ends.

Subsequently, the molten resin supplied to the horizontal main runner 21 through the sprue 19 and the vertical runner 20, ie, the sprue, reaches the branch point A, and the auxiliary runner 22 extended to the left and right sides. When the feed is divided into furnaces, according to the role of the runner core pin 36 to guide the flow of molten resin evenly to the left and right, the molten resin having the same flow rate and viscosity to the cavity 25 located on the left and right sides Will be supplied.

In addition, the mold constituting the plurality of cavities 25 as described above generally divides the molten resin into both ends of the horizontal main runner 21, that is, the auxiliary runner 22 extending from the branch point A to the left and right sides. After the supply, the molten resin is injected into the cavity 25 through the gate 22a formed in the auxiliary runner 22.

Therefore, although eight cavities are formed in FIG. 3 as an embodiment according to the present invention, in the present invention, application and effects may be generated in an injection mold in which at least four or more cavities are formed. .

After completion of the injection process as described above, after the cooling of the predetermined time, by the angular pin 30 is moved in the vertical direction and simultaneously with the opening action to perform the take-out process to drop the molded product from the mold. The slider 35 moves horizontally on the movable side plate 14, and is fixed to the stopper 37 by moving to the initial position.

That is, the runner core pin is repeatedly interlocked with the branch point A in the runner while the mold is opened and closed during the injection process so that the molten resin is equally filled in each cavity.

4 is a cross-sectional view illustrating a configuration of an injection mold for hot runners in which fixed core pins are installed according to another embodiment of the present invention, and FIG. 5 illustrates a plurality of cavities applied to an injection mold for hot runners according to another embodiment. And showing a perspective view showing the configuration of the runner,

According to the present invention, the runner manifold plate 40 is also used in a general hot runner injection mold having a runner manifold plate 40 having a separate preheating device in which the molten resin in the runner always maintains a constant temperature. The supply of molten resin is performed equally to the plurality of cavities 25-1 that are symmetrical left and right around the horizontal main runner 21-1 to be formed.

That is, the fixed side mold plate 12-1) is attached to the upper fixed side mounting plate 11-1), and the movable side plate 14-1 is attached to the lower movable side mounting plate 13-1). It is mounted, but between the fixed side mounting plate (11-1) and the fixed side plate (12-1) between the sprue (19-1) and the vertical runner of the central portion of the fixed side mounting plate (11-1) ( 20-1) is supplied to the molten resin, and the molten resin passes through the horizontal main runner 21-1, reaches both ends of the horizontal main runner 21-1, and extends to the left and right sides, respectively. It is divided and supplied through the runner 22-1 to supply molten resin to a plurality of cavities 25-1 formed symmetrically by the fixed side plate 12-1 and the movable side plate 14-1. In the plastic plastic injection mold for hot runner provided with a runner manifold plate 40 having a preheating device,

Separate fastening members 38 on both inner sides of the runner core pins 36-1, on which the curved front ends protrude to the centers of both ends of the horizontal main runner 21-1 formed by the runner manifold plate 40. Configure by installation.

In this way, the molten resin supplied to the horizontal main runner 21-1 formed by the runner manifold plate 40 reaches the branch point A-1 to the auxiliary runner 22-1 extending on the left and right sides. When dividedly supplied, according to the role of the runner core pins 36-1 that guide the flow of the molten resin to the left and right sides evenly, the cavity 25- located at the left and right sides having the same flow rate and viscosity To 1).

Accordingly, the present invention is not limited to the four cavities 25-1 shown in FIG. 5, which is illustrated as another embodiment, and a plurality of symmetrical left and right symmetries around the horizontal main runner 21-1. Of course, it can be applied to the injection mold for hot runner to form a cavity.

The preheating device inherent in the runner manifold plate 40 forming the runner inward is a well-known technology and detailed description thereof will be omitted.

Figure 6 shows a schematic view comparing the flow of the molten resin at a branch point according to the present invention,

As described above, the auxiliary runners 22, which are formed to extend left and right at both ends of the horizontal main runners 21 and 21-1 in order to supply molten resin to a plurality of cavities using a cold runner type and a hot runner type injection mold. 22-1) is to supply molten resin evenly.

As described above, this turns around the outer portion P ', that is, the outer corner, of the melted resin which is bent left and right at the branching points A and A-1 of the horizontal main runners 21 and 21-1. As the outgoing molten resin comes into contact with the leading curved portions of the runner core pins 36 and 36-1, the flow rate increases due to the increase in the shear rate and the frictional heat. In order to maintain the uniformity of the filling profile of the molten resin supplied to the auxiliary runner 22 formed in each branch by flowing evenly with the molten resin passing through the close corner (conner).

At this time, the curved shape of the front end portion of the runner core pins 36 and 36-1 and the proper distance inserted into the branch point A can be changed depending on the fluid characteristics of the molten resin.

In addition, the runner core pins 36 and 36-1 may control the temperature according to the fluid characteristics of the molten resin under the control of a thermostat (not shown) installed outside using electricity as an external force.

Reference numeral 41 is a hot bush.

The present invention is not limited to the above-described specific preferred embodiments, and various modifications can be made by any person having ordinary skill in the art without departing from the gist of the present invention claimed in the claims. Of course, such changes will fall within the scope of the claims.

As described above, when the molten resin is branched into the auxiliary runner divided into the left and the right through the horizontal main runner, the present invention provides a molten resin supplied to each auxiliary runner by a runner core pin for guiding the flow of the molten resin. By achieving a balanced charging of, there is an effect that can be prevented in advance a variety of molding failure of the product formed in a plurality of cavities.

Claims (3)

The fixed side plate 12 is mounted on the upper fixed side mounting plate 11, and the movable side plate 14 is mounted on the lower movable side mounting plate 13 to the center of the fixed side plate 12. The molten resin is supplied through the sprue 19 and the vertical runner 20, and the molten resin passes through the horizontal main runner 21 to reach both ends of the horizontal main runner 21 and extends left and right. In the cold runner plastic injection mold, which is dividedly supplied through each auxiliary runner 22 to supply molten resin to a plurality of cavities 25 formed symmetrically, The angular pin 30 is installed at the lower end of the fixed side mounting plate 11 to penetrate the fixed side plate 12 and have a predetermined inclination angle; An inclined through hole 35a corresponding to accommodate the inclined angular pin 30, and is located between the stationary side plate 12 and the movable side plate 14 on the movable side plate 14; It is installed to slide in the longitudinal direction of the horizontal main runner 21, and constitutes a slider 35 having a runner core pin 36 on one side; As the mold is opened and closed, curved ends of the runner core pins 36 formed on the slider 35 are inserted into and separated from the centers of both ends of the horizontal main runner 21, and are supplied to the auxiliary runners 22 on the left and right sides. Runner core pins for balanced filling of plastic injection molding, characterized in that equal division of the molten resin occurs. A fixed side plate 12-1 is mounted on the fixed side mounting plate 11-1 at the top; The movable side plate 14-1 is mounted on the movable side mounting plate 13-1 at the lower portion; A preheating device is provided in the section between the fixed side mounting plate 11-1 and the fixed side plate 12-1, and the sprue 19-1 at the center of the fixed side mounting plate 11-1 and The molten resin is supplied through the vertical runner 20-1, and the molten resin extends left and right through the horizontal main runner 21-1 and reaches both ends of the horizontal main runner 21-1. The molten resin is dividedly supplied through the auxiliary runners 22-1 to the plurality of cavities 25-1 formed symmetrically by the fixed side plate 12-1 and the movable side plate 14-1. In the plastic plastic injection mold for hot runner having a runner manifold plate 40 to be supplied, The runner core pins 36-1 are fixed to the centers of both ends of the horizontal main runner 21-1 formed in the runner manifold plate 40, and the curved runner core pins 36-1 are positioned to protrude. Runner core pins for balanced filling of plastic injection molding, characterized in that the equal division of the molten resin supplied to (22-1) occurs. The method according to claim 1 or 2, The runner core pin (36,36-1) is a plastic injection molding balance filling runner core pin, characterized in that the temperature control is possible.

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