KR20110021593A

KR20110021593A - Screw thread maker of injection mold

Info

Publication number: KR20110021593A
Application number: KR1020090079476A
Authority: KR
Inventors: 정종호
Original assignee: 창성정밀(주)
Priority date: 2009-08-26
Filing date: 2009-08-26
Publication date: 2011-03-04

Abstract

PURPOSE: A screw forming device of an injection mold is provided to simultaneously form a plurality extrudates with screw thread and to easily discharge by rotating a plurality of cores with a rotary unit. CONSTITUTION: A screw forming device of an injection mold comprises a plurality of rotary cores(31) and a rotary unit. A plurality of rotary cores is installed in the upper mold or the low mold to rotate. The rotary cores form screw threads on a molded product using forming projections(33). When the upper and lower molds are separated after finishing the molding, a driving unit of the rotary unit simultaneously rotates a plurality of rotary cores in order to separate a rotary core from a molded product.

Description

Screw molding machine for injection mold {screw thread maker of injection mold}

The present invention relates to a screw molding apparatus of an injection mold, and more particularly, having a rotation unit capable of rotating a core member for forming the screw thread so as to produce a plurality of injection-molded injection products in one mold. The present invention relates to a thread forming apparatus for an injection mold.

In general, a mold is a metallic mold made to produce large quantities of products of the same standard, and is widely used in electric and electronic products as well as daily necessities such as automobiles, aircraft, semiconductors, communication devices, and precision machines, to ultra-precision products. Used.

Among the molds, there are injection molds for producing a product by injecting a synthetic resin, and there are products in which the thread is formed in the fastening hole due to the characteristics of the product produced by the injection mold. By forming the thread on the outer peripheral surface of the injection molding is completed, the fastening hole of the product can be made to have a thread having a plurality of pitch on the inner peripheral surface.

By the way, in general injection molding, after the molten resin is solidified and the upper and lower molds are separated, the solidified product is pushed up with the take-off pin to take out the product. However, in the case of the injection-molded injection mold, the thread of the fastening hole Since the thread of the core is fastened, it cannot be separated through vertical mold separation. Therefore, there is a need for a rotary unit that can rotate the core to separate the core and the injection molded product.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object thereof is to provide an injection mold screw forming apparatus having a rotation unit capable of rotating a core to form an injection molded article including a thread.

Another object of the present invention is to provide a screw molding apparatus of an injection mold formed so that the rotary unit can rotate a plurality of cores so as to manufacture a plurality of molded articles having a thread in one mold.

In the injection molding screw forming apparatus according to the present invention, the upper mold or the lower mold in the injection mold including the upper and lower molds which are mutually combined or mold-separated, forming a predetermined cavity corresponding to the shape of the injection molding through the molding. Rotating core is rotatably installed in the mold, and the rotating core is formed in the outer peripheral surface to be inserted into the cavity when forming the upper and lower molds to form a thread in the molded product, the upper mold or the lower mold After the molding of the product is completed, when the upper and lower molds are separated, characterized in that it further comprises a rotary unit for rotating the rotary core so that the rotary core can be separated from the solidified molded product .

When the upper and lower molds are combined, a plurality of cavities are formed, and a plurality of rotatable cores inserted into each of the cavities are rotatably installed on the upper mold or the lower mold, and the rotation unit is the plurality of rotations. A driving part capable of rotating the core simultaneously, the driving part being driven by a sprocket coupled to each of the rotary cores, a driving sprocket rotatably installed on the upper mold or the lower mold, and rotating the driving sprocket. It is preferable to have a drive motor to make and a chain connecting the drive sprocket and the driven sprockets so as to transmit the rotational force of the drive sprocket to the plurality of driven sprockets.

The rotating core may further include a tapered portion whose outer diameter gradually increases as it extends along the direction away from the cavity from the end of the forming protrusion, and an inclined section corresponding to the tapered portion is formed in the upper mold or the lower mold. .

The screw molding apparatus of the injection mold according to the present invention has the advantage that it can be easily withdrawn after molding a plurality of injection molding products having a thread at the same time.

Hereinafter, with reference to the accompanying drawings will be described in more detail the screw molding apparatus of the injection mold according to the present invention.

1 shows an injection molding 1 molded by an injection mold 10 comprising a thread forming apparatus 30 according to the invention.

As shown, the injection-molded product 1 is molded using a synthetic resin, and has a fastening groove 2 having a predetermined depth drawn upward on a lower surface thereof and a thread 3 formed on an inner circumferential surface thereof.

The shape of the injection molded product 1 may be variously formed according to its purpose and use, and various types of injection molded products 1 having a fastening groove 2 having a thread 3 formed on one side thereof may be manufactured.

2 and 3, an injection mold 10 for molding the injection product 1 is shown.

The injection mold 10 of the present embodiment is combined with each other to form upper and lower molds 11 and 20 to form a cavity 12 for molding the injection molding 1, and the injection molding is installed on the lower mold 20 ( It includes a screw forming apparatus 30 for forming a fastening groove (2) of 1).

The lower mold 20 of the present embodiment is fixed in position, the upper mold 11 is raised or lowered in the vertical direction from the upper side of the lower mold 20 between the upper mold 11 and the lower mold 20 Molding and separation are achieved. Of course, the upper mold 11 is fixed and the lower mold 20 is movable may be made to form and separate the mold.

In addition, the lower mold 20 is rotatably supported by a rotating core 31 to be described later therein, the first and second lifts formed to be raised or lowered by an actuator (not shown) inside the lower mold 20. Steel sheets 21 and 22;

An installation space 23 for installing the rotary unit 40 to be described later is formed between the first and second lifting plates 21 and 22.

The screw forming apparatus 30 includes a rotating core 31 rotatably installed in the lower mold 20 and a rotating unit 40 for rotating the rotating core 31.

In the injection mold 10 of the present embodiment, a plurality of cavities 12 are formed by the combination of the upper and lower molds 11 and 20, and the fastening groove 2 is formed in the injection molding 1 formed in each cavity 12. ), A plurality of rotating cores 31 which can be inserted into the cavities 12 are rotatably installed on the first and second lifting plates 21 and 22.

The rotary core 31 includes an insertion portion 32 inserted into the cavity 12, a tapered portion 34 extending a predetermined length downward from the lower end of the insertion portion 32, and a tapered portion 34. The 1st extension part 35 extended below from the lower end of this, and the 2nd extension part 36 extended downward from the lower end of the 1st extension part 35 are provided.

The molding protrusion 33 is provided in the outer peripheral surface of the insertion part 32, This molding protrusion 33 corresponds to the screw thread 3 for forming in the injection molded object 1. As shown in FIG. The molten resin filled in the cavity 12 by the molding protrusion 33 is molded to form the thread 3, and by adjusting the pitch and size of the molding protrusion 33, the injection molding 1 is required. It can be molded to have a matching thread (3).

The tapered portion 34 extends downward from the lower end of the insertion portion 32, the outer diameter is formed to gradually widen as the extension is made downward.

The first extension portion 35 is formed to extend a predetermined length downward from the end of the tapered portion 34, the second extension portion 36 is connected to the lower end of the first extension portion 35, the second extension Since the outer diameter of the part 36 is relatively smaller than the outer diameter of the first extension part 35, the first and second extension parts 35 and 36 are connected to the connection portions of the first and second extension parts 35 and 36. The stepped portion is formed by the difference in outer diameter.

The second extension part 36 penetrates through the first elevating plate 21 and is supported such that the lower end thereof is rotatable to the second elevating plate 22.

A hollow 24 is formed in the first elevating plate 21 of the lower mold 20 so that the above-described rotary core 31 can be extended in a vertical direction. The hollow 24 has the tapered portion. And an inclination section 25 corresponding to 34 and first and second extension sections 26 and 27 corresponding to the first and second extension parts 35 and 36.

In particular, the inclined section 25 is formed to increase in diameter as the taper portion 34 is extended downward so that the taper portion 34 can be installed, the taper portion 34 and the inclined section 25 proceeds upwards in diameter Since it is formed to become smaller and smaller, the upper and lower molds of the insertion part 32 in the process of being inserted into the cavity 12 as the rotary core 31 ascends in accordance with the lifting of the first and second elevating plate (21, 22) The collision between 20 is prevented from occurring, and the lifting direction in which the insertion portion 32 is inserted into the cavity 12 is guided.

In addition, when the first and second lifting plates 21 and 22 are lifted by the step formed between the first and second extension parts 35 and 36, the rotary core 31 is lifted by the first and second lifts. It is possible to move up and down together with the steel sheets 21 and 22.

In addition, as described above, the installation space 23 is provided so that the rotation unit 40 may be installed between the first and second lifting plates 21 and 22, and the respective rotations may be performed through the installation space 23. Some sections of the second extension 36 of the cores 31 are all exposed.

The rotary unit 40 is for rotating each of the rotary cores 31, the bearing 41 is installed in the lower mold 20 to facilitate the rotation of the rotary core 31, and the It is provided with a drive unit 42 for transmitting a rotational force to each rotary core (31).

The bearing 41 is installed one each on the upper end of the second extension portion 36 and the upper side of the installation space 23, the rotary core 31 is easy to the lower mold 20 by the bearing 41. Since it can rotate so as to minimize the damage caused by the friction between the inner core of the rotary core 31 and the hollow 24.

The driving unit 42 is for rotating the plurality of rotating cores 31 at the same speed at the same time, and is rotatably driven by the driven sprocket 43 and the lower mold 20 coupled to the respective rotating cores 31. A drive sprocket 44 to be installed, a drive motor 45 for rotating the drive sprocket 44, and a chain 46 connecting the drive sprocket 44 and each driven sprocket 43 are included.

The driven sprocket 43 is installed to surround the outer circumferential surface of the second extension portion 36 passing through the installation space 23, and is coupled to allow the rotational force to be transmitted to the rotating core 31 through the driven sprocket 43. have.

In particular, since the driven sprocket 43 has a larger diameter than the second extension section 27, when the first and second lifting plates 21 and 22 descend, the lower surface of the first lifting plate 21 is the driven sprocket. As the driven sprocket 43 is pressed by the first elevating plate 21 in contact with the 43, the rotary core 31 is lowered.

Drive sprocket 44 is rotatably installed on one side of the installation space 23, each drive sprocket 44 and the driven sprocket 43 is connected so that the power transmission can be made by the chain 46 It is.

In addition, the driving motor 45 is installed on the first elevating plate 21 to apply the rotational force to the driving sprocket 44.

When the drive motor 45 rotates the drive sprocket 44 in one direction, the driven sprockets 43 rotate together with the drive sprocket 44 by the chain 46, thereby rotating the rotation core 31. Can be.

The rotational speed of the rotary core 31 should correspond to the descending speeds of the first and second elevating plates 21 and 22 falling after the molten resin solidified in the cavity 12 is solidified.

If the rotational speed of the rotary core 31 and the lowering speeds of the first and second elevating plates 21 and 22 do not match, the thread 3 formed in the injection molded product 1 is inserted into the insert 32 and the injection molded product ( 1) separation is not naturally separated by the rotation of the rotary core 31, but the rotary core 31 is forcibly lowered and separated, or the insert 32 is inserted into the fastening groove 2 of the injection molding 1. This is because the thread 3 in the injection molding 1 is broken by being rotated more than the length of the thread 3 formed at.

Therefore, since it is very important to maintain and adjust the speed of the rotating core 31 constantly, it is preferable to transmit power through the chain 46 so as to accurately transmit the rotational force of the driving motor 45.

In the present embodiment, four cavities 12 are formed in one mold, and four rotary cores 31 inserted into the cavities 12 are also provided. And the cavity 12 is formed so that the drive sprocket 44 and the driven sprockets can be arranged inline, on the other hand, a plurality of cavities 12 may be arranged in a variety of patterns, the chain 46 Additional idle sprockets can also be installed to facilitate connection.

In addition, in the present embodiment, since the forming directions of the threads 3 formed on the respective injection moldings 1 are all the same, the driving part 42 is different from the driving sprocket 44 so that the rotation direction of the rotating core 31 is the same. The driven sprocket 43 is formed so that it can be connected through the chain 46.

On the other hand, however, in the case of forming two kinds of injection moldings 1 which are different in the forming direction of the thread 3, the power transmission of the driving motor 45 may be formed to be coupled by a gear.

That is, a drive gear rotated by the drive motor 45 and a driven gear part engaged with the drive gear may be provided. The driven gear part may be alternately engaged with the first driven gear and the second driven gear. Can be formed.

The rotating core 31 is rotated by the combined driving gear and the driven gear part. Since the power is transmitted through the gear coupling, the rotation directions of the first and second driven gears are opposite to each other. As the rotation direction of the rotary core 31 is also reversed, the forming direction of the thread 3 can be formed in different directions from each other.

However, if the forming direction of the screw thread 3 formed in the injection molding 1 is the same as in this embodiment, in order to transmit power through gear coupling, the rotation direction of the driven gear installed in each rotary core 31 is The manufacturing cost can be excessively high because separate idle gears that interconnect driven gears must be installed to be identical. Therefore, as shown in this embodiment, when the forming directions of the threads 3 formed on the injection molding 1 are all the same, it is most preferable to transmit the rotational force through the chain coupling.

Referring to the process of injection molding through the injection mold (10) comprising a screw molding apparatus of the injection mold according to the present invention.

First, the upper mold 11 is lowered to form the upper and lower molds 11 and 20, and the first and second lifting plates 21 and 22 are lifted by the actuator to be inserted into the upper end of the hollow 24. The cavity 12 is formed by the insertion portion 32 of the rotating core 31.

After that, the molten resin supplied through the sprue bush 13 passes through the runner 14 and is filled in the cavity 12, and after a predetermined time, the molten resin solidifies.

When the molten resin solidifies, the first and second elevating plates 21 and 22 descend, and at this time, the driving sprocket 44 is rotated by the driving of the driving motor 45, and the rotational force is driven by the chain 46. As it is transmitted to each driven sprocket 43, each rotating core 31 is rotated. As the rotary core 31 rotates, the thread 3 formed on the injection molded product 1 and the forming protrusion 33 formed on the outer circumferential surface of the insertion part 32 are separated from each other.

Subsequently, the upper mold 11 is lifted and the upper and lower molds 11 and 20 are separated from each other, and the injection molded product 1 having completed molding is taken out from the upper mold 11 and then the upper mold 11 and the lower mold 20 ) Again to repeat the same process described above.

1 is a partially cut perspective view showing an injection molded through an injection mold having a screw molding apparatus for an injection mold according to the present invention;

2 is a cross-sectional view showing an injection mold including a screw molding apparatus for an injection mold according to the present invention;

3 is a partial perspective view showing the screw forming apparatus of FIG.

30; Screw forming equipment

31; Rotating core

40; Rotating Unit

42; Driving part

Claims

In the injection mold including the upper and lower molds which are mutually matched or mold-separated, and forming a plurality of cavities corresponding to the shape of the injection molding through the joining,

A plurality of rotating cores rotatably installed on the upper mold or the lower mold, and having a molding protrusion formed on an outer circumferential surface of the upper mold and the lower mold to be inserted into the cavities to form a thread in the molded product, respectively. ;

Rotating the plurality of rotary cores simultaneously so that the rotary core can be separated from the solidified molded product when the upper and lower molds are separated from each other after the molding of the product is completed and the molding of the product is completed. Rotating unit including a drive unit capable of making; screw injection molding machine comprising a.

The method of claim 1,

The drive unit includes a driven sprocket coupled to each of the rotary cores;

A drive sprocket rotatably installed on the upper mold or the lower mold;

A drive motor for rotating the drive sprocket;

And a chain for interconnecting the drive sprocket and the driven sprockets so as to transmit rotational force of the drive sprocket to the plurality of driven sprockets.

The method according to claim 1 or 2,

The rotating core is rotatably supported by a lifting plate which is installed on the upper mold or the lower mold so as to be lifted and lowered by an actuator, and the hollow formed in the upper mold or the lower mold so that the rotating core can be inserted into the cavity. There is,

The rotating core has a tapered portion having an outer diameter gradually increasing as it extends in a direction away from the cavity from the end of the insertion portion, and the hollow includes an inclined section corresponding to the tapered portion. Device.