KR19990020315U - Eject pin breakage structure of mold base - Google Patents

Abstract

The present invention discloses an eject pin break prevention structure of a mold base. In the conventional mold base break prevention structure of the eject pin, since the stroke of the eject pin is determined by the movement of the upper and lower plates, deformation and breakage of the eject pins are easily generated due to an error generated when the upper and lower plates are moved. According to the present invention, a bolt having an extension part is fastened to one side of the lower surface of the movable template, and the guide hole of the stopper is fitted to be mounted so that the stroke of the eject pin is restricted by selectively contacting the upper mill plate with the extension part of the bolt. At one end of the hole a head seating hole is formed to catch the head of the bolt and prevent it from coming off. Therefore, since the stroke of the eject pin is precisely regulated while the moving distance of the upper plate is regulated, the deformation and breakage of the eject pin are effectively prevented, thereby significantly improving productivity and workability.

Description

Eject pin breakage structure of mold base

The present invention relates to a mold base for injection molding, and more particularly, to an eject pin break prevention structure of a mold base to prevent deformation and breakage of an eject pin.

Injection molding is a method of manufacturing a product having a predetermined shape and dimension by injecting a molten molding material, for example, a thermoplastic resin, into a cavity of a mold base, and injection molding is generally performed automatically by an injection molding machine. The mold base required for injection molding is configured to be divided into a pair of fixed and movable templates.

Looking at one example of such an injection molding method, the injection molding machine is a heating cylinder for melting a molding material supplied from a hopper by heating, and a mold base for molding a molding material in a molten state by heating of the heating cylinder. Can be divided into The mold base is configured such that a pair of stationary and movable templates have cavities on their parting line. Here, the cavity is usually formed in the dividing surface of the stationary template, the stationary template is fixed to the heating cylinder, and the cavity is selectively opened and closed by the operation of the movable template. The movable template is actuated by the operation of the clamp mechanism, and the injection molding machine is equipped with an eject mechanism for removing the molded article in the molded state from the cavity of the mold base.

Therefore, when a predetermined time elapses after the molten molding material is injected into the cavity by heating the heating cylinder while the cavity is closed by the operation of the movable template, the cavity is opened by the operation of the movable template and ejected. The injection-molded article molded by the operation of the mechanism is pushed out of the cavity and then solidified to produce a desired article.

Injection molding, on the other hand, can produce a variety of different types of objects, such as panels, boards, boxes, and cylindrical containers, and electronics such as video cassette recorders (VCRs) and compact disc players (CDPs). It is used for manufacture of a cover. As an example of an electronic product, in the case of a video cassette recorder, a chassis and a front panel are manufactured by injection molding, and bosses, pins, holes, etc. are formed in the chassis and the front panel of the video cassette recorder.

As shown in FIG. 1, in the mold base 10, a fixed template 12 is assembled to one side of the fixed mounting plate 11, and a cavity 13 is formed on a divided surface of the fixed template 12. Is formed. In the mold base 10, a space block 15 and a movable template 16 are assembled to one side of the movable mounting plate 14, and a core mounting hole 17 is formed in a divided surface of the movable template 16. do. The core 18 is provided in the core mounting hole 17 of the movable template 16, and the core 18 is fitted to the cavity 13 of the stationary template 12 to form the desired injection molded product P. Is achieved.

In addition, upper and lower contact plates 19 and 20 are respectively mounted at the center of one surface of the movable template 16, and eject pins 21 are mounted at one side of the lower contact plate 20, and the other of the lower contact plate 20 is provided. A return pin 22 is attached to the side, and a spring 23 for imparting a predetermined elastic force is attached to the outer circumferential surface of the return pin 22.

In addition, the guide pin bush 24 is disposed and mounted on the fixing template 12, and the guide pin 25 is fitted to the core 18 in a corresponding relationship with the guide pin bush 24. Are mounted. The core 18 is fitted to the cavity 13 by fitting the guide pins 25 into the guide pin bushes 24 correspondingly to each other.

In the conventional mold base mounting structure of the eject pin, as shown in FIG. 2, the eject pin 30 is mounted upward on the upper surface of the lower mill plate 20 described in FIG. 1, and the eject pin 30 has a large diameter. At the end of the first rod 31, a second rod 32 having a small diameter is formed in series by a taper 33. As shown in FIG. Eject pin 30 is the catch of the fixed template 12 through the guide hole 35 of the movable template 16 and the guide hole 36 of the core 18 in accordance with the movement of the upper and lower contact plates (19, 20). It is mounted so that it is selectively sunk toward the vertices 13. Here, the guide hole 36 of the core 18 is formed such that the diameter thereof catches the first rod 31 of the eject pin 30. As the eject pin 30 protrudes into the cavity 13 as described above, the injection molded product P of the cavity 13 is pushed out.

However, as described above, the ejection pin breakage prevention structure of the mold base has the upper and lower tight plates (stroke) of the eject pins 30 determined by the movement of the upper and lower tight plates 19 and 20. There was a problem that deformation and breakage of the eject pin 30 are easily generated due to an error generated when the 19 and 20 are moved. In other words, when the upper and lower plates 19 and 20 are moved beyond the prescribed distance toward the fixed template 12, the stroke of the eject pin 30 becomes relatively large and the second rod of the eject pin 30 ( 32 is in contact with the guide hole 36 of the core 36, and at this time the load is applied to the eject pin 30 will be broken in case of deformation or severe cases of the eject pin 30.

Therefore, there is a problem in that productivity is remarkably lowered due to deformation and breakage of the eject pin 30. In addition, in order to replace the eject pin 30 with a new one, the upper and lower contact plates 19 and 20 of the mold base 10 need to be dismantled, and thus workability is remarkably degraded, such as unnecessary work time.

The present invention is devised to solve the conventional problems as described above, the object of the present invention is the eject pin of the mold base to precisely regulate the stroke of the eject pin by a simple configuration and structure to prevent deformation and breakage To provide a breakage prevention structure.

1 is a cross-sectional view showing a general mold base,

2 is a cross-sectional view showing an eject pin installation structure of a conventional mold base;

3 is a cross-sectional view showing an eject pin break prevention structure of a mold base according to the present invention;

4 is a cross-sectional view showing an operating state of FIG. 3;

Figure 5 is a cross-sectional view showing an embodiment of the eject pin break prevention structure of the mold base according to the present invention.

♣ Explanation of symbols for the main parts of the drawing ♣

10: mold base 11: fixed mounting plate

12: fixed template 13: cavity

14: operation mounting plate 16: operation template

17: core mounting hole 18: core

19: upper plate 20: lower plate

40: eject pin 51: bolt

55: stopper 56: guide hole

61: guide post 63: bolt

66: stopper 67: guide hole

A feature of the present invention for achieving the above object is a movable plate which is assembled to have a cavity on one side of the fixed mounting plate, and a core which is assembled to one side of the movable mounting plate and fitted to the cavity of the fixed plate. A mold base comprising a template, an upper and lower mill plate mounted at the center of one side of the movable template, and an eject pin mounted to one side of the lower mill plate to push out the injection molded product from the cavity, A bolt having an extension part is fastened to the end of the head, and the guide hole of the stopper is fitted to be mounted so that the extension of the bolt selectively contacts the upper mill plate to regulate the stroke of the eject pin. The ejection pin breakage prevention structure of the mold base in which the head seating hole is formed so as to prevent this.

Another feature of the present invention is a stationary template assembled to have a cavity on one side of the stationary mounting plate, a movable template on which a core assembled to one side of the movable installation plate and fitted into the cavity of the stationary template is installed, In a mold base having an upper and a lower plate mounted at the center of one side and an eject pin mounted at one side of the lower plate to push the injection molded product out of the cavity, the guide post is fastened to the upper side of the movable mounting plate by a bolt. The guide hole of the stopper is mounted on the outer circumferential surface of the guide post so that the through-holes of the upper and lower plates correspond to each other, and the contact hole of the stopper is selectively contacted with the movable template on the upper circumferential surface of the guide post to restrict the stroke of the eject pin. Eject pin breakage prevention structure of the mold base to be inserted and mounted.

Hereinafter, a preferred embodiment of the eject pin breakage preventing structure of the mold base according to the present invention will be described in detail with reference to the accompanying drawings.

3 to 4 are views for explaining the eject pin break prevention structure of the mold base according to the present invention, the basic configuration of the mold base described in Figure 1 will be described with the same reference numerals.

First, referring to FIG. 1 and FIG. 3, the mold base 10 has a fixed mounting plate 11 installed in a heating cylinder of the injection molding machine described above, and a fixed template 12 on one side of the fixed mounting plate 11. ) Is assembled by fastening, and the cavity 13 is formed on the divided surface of the stationary template 12.

In the mold base 10, the movable mounting plate 14 is attached to the clamping mechanism of the injection molding machine, and the space block 15 and the movable die plate 16 are assembled to one side of the movable mounting plate 14 by fastening, respectively. The core mounting hole 17 is formed in the divided surface of the movable template 16, and the core 18 is provided in the core mounting hole 17 of the movable template 16. As shown in FIG. The core 18 is fitted in a relationship corresponding to each other in the cavity 13 of the stationary template 12 to form the desired injection molded article P. At this time, the movable mounting plate 14 is moved by the clamp mechanism to open or close the cavity 13 of the stationary template 12. In this way, when the molding material in the molten state is injected from the heating cylinder into a shape in which the cavity 13 and the core 18 are fitted, a desired injection-molded article P is produced.

In addition, upper and lower contact plates 19 and 20 are mounted at the center of one surface of the movable template 16, and eject pins 40 are mounted at one side of the lower contact plate 20, and the eject pins 40 are ejected. The molded article P is pushed out of the cavity 13. At this time, the space in which the upper and lower plates 19 and 20 can move upward and downward is secured by the space block 15. A return pin 22 is mounted on the other side of the lower plate 20, and a spring 23 for imparting a predetermined elastic force is mounted on the outer circumferential surface of the return pin 22, and the return pin 22 is fixed and movable template ( When the 12 and 16 are closed, the upper and lower plates 19 and 20 are returned to their initial positions.

A plurality of guide pin bushes 24 are disposed and mounted on the fixing template 12, and a plurality of guide pins 25 are inserted into the core 18 so as to be fitted in a corresponding relationship with the guide pin bushes 24. Is mounted. The core 18 is fitted to the cavity 13 by fitting the guide pins 25 into the guide pin bushes 24 correspondingly to each other. That is, the guide pin bushes 24 and the guide pins 25 serve as guides for accurately fitting the fixed and movable templates 12 and 16, where the guide pin bushes 24 and the guide pins 25 are used. ) Are about four used.

As shown in FIGS. 3 and 4, the eject pin 40 is formed such that the second rod 42 having a smaller diameter is connected to the end of the first rod 41 having a larger diameter by the taper 43. The eject pin 40 catches the fixed template 12 through the guide hole 45 of the movable template 16 and the guide hole 46 of the core 18 as the upper and lower plates 19 and 20 move. It is mounted so that it is selectively sunk toward the vertices 13. Here, the guide hole 46 of the core 18 is formed such that its diameter is caught by the first rod 41 of the eject pin 40. That is, the first rod 42 of the eject pin 40 is inserted into the guide hole 46 of the core 18, and the second rod of the eject pin 40 is inserted into the guide hole 45 of the movable template 16. As the rod 43 is inserted and guided, the rod 43 is mounted so that the rod 43 can be settled.

On the other hand, the screw hole 50 is formed in one side of the lower surface of the movable template 16, and the bolt 51 is fastened to the screw hole 50 of the movable template 16. As shown in FIG. The bolt 51 has an extension portion 53 having a predetermined length on one side of the head 52, and a screw 54 fastened to the screw hole 50 is formed at the end of the extension portion 53.

In addition, the stopper 55 is formed in a substantially cylindrical shape so as to selectively contact the upper plate 19 with the extension part 53 of the bolt 51 to restrict the stroke of the eject pin 40. Guide hole 56 is formed in the center of 55 so as to be fitted to extension part 53 of bolt 51 and to be able to move freely in a vertical direction. The stopper 55 has a head seating hole 57 formed at one end of the guide hole 56 so as to be caught by the head 52 of the bolt 51 and prevented from being separated. Here, the head seating hole 57 of the stopper 55 is formed by counterboring.

5 shows an embodiment of the ejection pin breakage preventing structure of the mold base according to the present invention. A through hole 60 is formed in one side of the movable mounting plate 14, and the penetration of the movable mounting plate 14 is performed. The bolt 63 is fastened to the screw hole 62 of the guide post 61 through the hole 60, and the guide post 61 is erected perpendicularly to one side of the upper surface of the movable mounting plate 14. Is mounted. The through holes 64 and 65 of the upper and lower plates 19 and 20 are fitted to the outer circumferential surface of the guide post 61 so as to correspond to each other, and the upper and lower plates 19 and 20 are connected to the guide posts 61. It is mounted to move along the outer circumferential surface. In addition, the guide hole 67 of the stopper 66, which is manufactured in a substantially cylindrical shape, is selectively mounted on the outer circumferential surface of the guide post 61 so that the stroke of the eject pin 40 is regulated. , The stopper 66 is mounted to be freely movable in the vertical direction along the outer circumferential surface of the guide post 61. The stopper 66 fitted to the outer circumferential surface of the guide post 61 is formed to a length such that it is not detached from the guide post 61 in a state where the movable mounting plate 14 is completely moved to the initial position.

Referring to the operation state of the eject pin break prevention structure of the mold base according to the present invention as described above are as follows.

First, as shown in FIGS. 3 and 4, the molding material in the molten state is injected in the state in which the core 18 of the movable template 16 is fitted into the cavity 13 of the stationary template 12, thereby injecting an injection molded article ( After P) is molded, the upper and lower mill plates 19 and 20 are ejected when the movable mounting plate 14 is returned to the initial position by the operation of the clamp mechanism and the cavity 13 of the fixed mold 12 is opened. It is moved toward the stationary template 12 by the operation of the ejector mechanism of the molding machine, for example the eject rod.

The first and second rods 41 and 42 of the eject pin 40 move together with the guide holes 45 and the core 18 of the movable template 45 together with the movement of the upper and lower plates 19 and 20. It protrudes into the cavity 13 through the guide hole 46 and pushes the injection molded product P out. As the upper and lower plates 19 and 20 are moved in this manner, the upper plate 19 comes into contact with the stopper 55 and the moving distance 19 is regulated, so that the stroke of the eject pin 40, that is, the top dead center is accurately Regulated.

Therefore, since the eject pin 40 is effectively prevented from moving beyond the prescribed distance toward the fixed template 12 due to an error generated when the upper and lower tight plates 19 and 20 move, the deformation of the eject pin 40 is prevented. And breakage is prevented and productivity improves remarkably. In addition, workability is remarkably improved such that unnecessary work time is eliminated due to the replacement of the eject pin 40.

As shown in FIG. 5, when the guide hole 67 of the stopper 66 is fitted to the outer circumferential surface of the guide post 61, the stopper 66 is in the process of moving the upper and lower plates 19 and 20. Touches the movable installation plate 14 and regulates the moving distance 19 of the upper wheat plate 19 as described above, so that the stroke of the eject pin 40 is precisely regulated.

On the other hand, the above-described embodiment is merely to describe one preferred embodiment of the present invention, the scope of application of the present invention is not limited to such, and can be changed appropriately within the scope of the same idea. For example, the shape and structure of each component specifically shown in the embodiment of the present invention can be modified.

As described above, according to the structure of the eject pin break prevention structure of the mold base according to the present invention, since the stroke of the eject pin is precisely regulated while the movement distance of the upper mill is regulated, the deformation and the breakage of the eject pin are effectively prevented, thereby improving productivity Sex is significantly improved.

Claims (2)

A stationary template that is assembled to have a cavity on one side of the stationary mounting plate, a movable template on which a core assembled to one side of the movable installation plate and fitted to the cavity of the stationary template is installed, and mounted on the center of one side of the movable template In the mold base having an upper and lower mill plate and an eject pin mounted to one side of the lower mill plate to push the injection molded article from the cavity, A bolt 51 having an extension portion 53 at the end of the head 52 is fastened to one side of the lower surface of the movable template 16, A guide hole 56 of the stopper 55 is fitted into the extension portion 53 of the bolt 51 to selectively contact the upper mill plate 19 so that the stroke of the eject pin 40 is restricted. Eject pin breakage prevention structure of the mold base, characterized in that the head mounting hole (57) is formed at one end of the guide hole (56) is caught by the head (52) of the bolt (51) to prevent separation. A stationary template that is assembled to have a cavity on one side of the stationary mounting plate, a movable template on which a core assembled to one side of the movable installation plate and fitted to the cavity of the stationary template is installed, and mounted on the center of one side of the movable template In the mold base having an upper and lower mill plate and an eject pin mounted to one side of the lower mill plate to push the injection molded article from the cavity, A guide post 61 is mounted on one side of the upper surface of the movable mounting plate 14 to fasten the bolt 63. The through holes 64 and 65 of the upper and lower contact plates 19 and 20 are fitted to the outer circumferential surface of the guide post 61 in a corresponding relationship. The guide hole 67 of the stopper 66 is inserted and mounted on the outer circumferential surface of the guide post 61 so as to selectively contact the movable template 16 to restrict the stroke of the eject pin 40. Eject pin breakage prevention structure of mold base.