JPS62161456A - Device for preventing movement of insert of die for molding - Google Patents

Abstract

PURPOSE:To prevent the movement and dislodgment of an insert and to prevent the generation of a defective molding by forming the min. radius of the noncircular shape on an insert side equal to or slightly smaller than the max. radius of the noncircular shape on a die side. CONSTITUTION:A projecting part 7b is provided to a core 7a of a movable liner 7 facing the cavity and the outside circumference of the projecting part 7b is formed to an elliptical shape. The insert 21 for a bearing formed to an annular shape is fitted onto the part 7b. The inside hole 21a of the insert 21 is formed to the elliptical shape which is similar to the ellipse on the outside circumference of the part 7b and is larger in diameter than the same. The motor axis d1 of the ellipse on the insert side is formed equal to or slightly smaller than the major axis d2 of the ellipse on the die side. The insert 21 is, therefore, slightly elastically deformed when the insert 21 is turned. Then the part near the minor axis d1 of the insert 21 and the major axis d2 of the projecting part 7b face each other and the inside hole 21a of the insert 21 contacts the outside circumference of the part 7b at two points. The insert and the projecting part are thus securely held.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applied to a die casting machine, a plastic injection molding machine, etc., in which an insert inserted into a molding die and molded at the same time moves or fits during injection molding. This invention relates to an insert movement prevention device for a molding die that prevents it from falling off from a joint.

[Conventional technology]

Injection molding using a die casting machine, plastic injection molding machine, etc., involves injecting molten metal or molten resin into the cavity of a mold and solidifying it to obtain an injection molded product. An insert such as a shaped bearing is often fitted into a mold protrusion facing into the mold cavity and molded simultaneously with the injection molded product.

[Problem that the invention seeks to solve]

However, in injection molding where inserts are inserted and molded at the same time, the inserts may move due to machine vibrations or the flow of molten material injected into the mold cavity, or the inserts may be damaged by the inserts on the mold side. When the part is facing downward, the insert may fall into the cavity, resulting in defective molded products and hindering automation and rationalization.

[Means for solving problems]

In order to solve these problems, in the present invention, the inner periphery of the insert and the outer periphery of the mold protrusion into which this insert is fitted are each formed into a non-circular shape such as an ellipse, and the non-circular shape on the insert side The minimum radius was set to be the same as or slightly smaller than the maximum radius of the non-circular shape on the mold side.

[Effect]

When the insert and the mold convex part are fitted with the maximum radii of a non-circular shape such as an ellipse aligned, and the insert is rotated, the part near the minimum radius of the insert and the part with the same diameter as the minimum radius or even more ＼The maximum radius of the small diameter mold faces each other and fits snugly, and the insert does not move even when injection is performed.

〔Example〕

This example shows an example in which the non-circular shape is oval, and FIGS. 1 and 2 are a front view, an I-I cross-sectional view, and a ■-■ cross-sectional view of the mold convex portion in which the insert is fitted, respectively. shows,
Figure 1 is a diagram where the minor axes of the ellipse correspond to each other and are 2,
Fig. 2 is a diagram showing the case where the vicinity of the short axis of the elliptical shape of the insert is in contact with the major axis of the convex part of the mold, and Fig. 3 is a longitudinal cross-sectional view of the vicinity of the mold of a die-casting machine in which the present invention is implemented. . In the figure, the die-casting machine is equipped with a fixed platen 1 erected on the machine space, and a movable platen 2 supported so as to be able to move forward and backward in the direction of distance.A fixed mold 3 is attached to the fixed platen 1. ing.

Further, a movable mold 4 is attached to the movable platen 2 via a pair of upper and lower die bases 5, and these fixed molds 3
A fixed insert 6 and a movable insert 7 are fitted into the recessed holes of the movable mold 4 and the fixed insert 6, respectively. The fixed insert 6 and the movable insert 7 are formed with four parts 6a and a core 7a that is engaged with the four parts 6a.
A cavity 8 is formed between the two. Reference numeral 9 denotes a fixed sleeve having a tapered inner hole fitted into the sleeve hole of the fixed insert 6, into which a tapered cylindrical member 10 fitted into the movable insert 7 engages during mold clamping. The sprue 11 is formed by this insertion. 12 and 13 are launches and gates provided between the sprue 11 and the cavity 8. In addition, fixed platen 1
A cylindrical injection sleeve 14 with a pouring port 14a is fitted concentrically with the fixed sleeve 9 into the sleeve hole of the fixed mold 3, and an injection shilling plunger (not shown) is fitted into the inner hole. A chip 15 is fitted so as to be freely retractable. Then, by supplying the molten metal 16 from the pouring port 14& and moving the plunger tip 15 forward, the molten metal 16 is injected from the injection sleeve 14 into the cavity 8 through the sprue 11, runner 12, and gate 13, and is solidified. The structure is such that a cast product as an injection molded product can be obtained.

On the other hand, a support pin 18 integrated with a support plate 17 that moves forward and backward by an extrusion cylinder (not shown) is engaged in a bottle hole provided in the movable platen 2, and has a plurality of extrusion pins 19 at its tip. An extrusion plate 20 is fixed. The extrusion pin 19 passes through the hole in the movable mold 4 and the movable slider 7 and reaches the cavity 8. After retracting the movable platen 2 and opening the movable mold 4, the extrusion pin 19 is inserted into the extrusion cylinder. By advancing the extrusion bin 19, the cast product within the cavity 8 is extruded.

In the die casting machine configured in this way, an insert is inserted into the cavity 8. That is, the core 7a facing into the cavity B of the movable insert T is provided with a convex portion 7b, and the outer circumference of the convex portion 7b is formed in an elliptical shape.

A ring-shaped bearing insert 21 is fitted on the outer periphery of the protrusion 7b, and the inner hole 21m of the insert 21 is similar to the oval shape of the outer periphery of the protrusion 7b and is larger than this. It is formed into a large diameter ellipse, and the short axis of the insert-side oval shown as d1 in the figure is the same diameter as the long axis of the mold-side oval shown as d, or slightly smaller than this. It is formed. That is, insert 21
When the insert 21 is fitted and rotated from the state shown in FIG. 1 to the state shown in FIG. 2, the insert 21 is slightly elastically deformed and the short diameter d of the insert 21, the vicinity and the convex portion 7b.

The inner hole 21a of the insert 21 and the outer periphery of the convex portion 7b are configured to be in contact with each other at two locations and to be firmly held. Although both ellipses are illustrated with the difference between the major axis and the minor axis greatly exaggerated in order to facilitate understanding, they are actually ellipses that are close to perfect circles.

The injection operation of the die casting machine configured as above will be explained. In the mold open state with the movable platen 2 retracted, the insert 21 is fitted into the convex portion 7b of the mold core 7&. At this time, when the long axes of the insert side ellipse and the mold side ellipse are fitted so that they correspond to y, and then rotated by 90 degrees, the short axis d1 of the insert 21 and the long axis d of the convex part 7b, Since the insert 21 is formed to satisfy d, ≦d, the short diameter d of the insert 21 is slightly elastically deformed.

The long diameter d of the convex portion 7b is in contact with the protrusion 7b in the vicinity, and is strongly supported by contacting at two places. Then, when the movable platen 2 is moved forward, mold clamping is performed and the core 1a is engaged in the recessed part to form the cavity 8.
When the plunger tip 15 is advanced by supplying the molten metal 16 from the sprue 11 and the runner 12. It is injected through the gate 13 into the trans-technical body 8. When the movable platen 2 is moved back after waiting for the molten metal 16 in the cavity 8 to solidify and cool down, the movable mold 4 is moved back and the mold is opened, and the cast product in the cavity 8 is transferred to the movable nest T. The mold is opened on the side. Therefore, when the extrusion plate 20 is advanced by the extrusion cylinder, the extrusion pin 19 protrudes into the cavity 8, and the cast product is extruded from the cavity 8.

In such an injection operation, if the machine vibrates and the mold 3.4 vibrates before or during the injection of the molten metal 16, or if the molten metal 16 flows in the cavity 8 after being injected, the insert 21 moves on the convex part Tb or the convex part 7
However, in this device,
As mentioned above, the short axis d of the insert 21 is the long axis d of the convex portion 7b.

By making the same diameter smaller than that, the insert 21 is slightly elastically deformed and comes into line contact with the convex portion 7b at two locations, and is firmly held by the mutual frictional force.
The insert 21 will not move or fall off.

Although the present embodiment shows an example in which the insert 21 is formed into a ring shape, the shape of the insert 21 is not limited, and any shape may be used as long as the inner hole is non-circular. In other words, it may be oval, rice ball shape, or the like. Further, although this embodiment shows an example in which the present invention is applied to a horizontal clamping mold of a die-casting machine, it can be similarly implemented to a vertical clamping mold. It can also be implemented in the same way.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, in the molding die, the inner periphery of the insert and the outer periphery of the mold protrusion into which the insert is fitted are each formed into a non-circular shape such as an ellipse. By forming the minimum radius of the non-circular shape on the insert side to be the same as or slightly smaller than the maximum radius of the non-circular shape on the mold side, when the insert is fitted into the mold convex part and rotated, the insert The insert is elastically deformed and comes into contact with the mold convex part at two places, and is firmly held by the mold convex part, so even if the injected molten material flows in the cavity when the machine vibrates, the insert will not move. It does not fall off, does not produce defective molded products, improves product yield, and promotes automation and rationalization. This effect is particularly great when the insert is attached to a downwardly facing mold convex portion.

[Brief explanation of drawings]

Figures 1 to 3 show an embodiment of the insert movement prevention device for a molding die according to the present invention, and Figure 1 (-) shows an insert where the long sides of the ellipse correspond to each other. FIG. 3 is a front view of a fitted mold convex portion. Figure 1 (1,) is a 1-1 sectional view of Figure 1 (-), ? g2
Figure (a) is a front view of the mold protrusion in which the insert is fitted, showing the area where the short axis of the insert's oval shape and the long axis of the mold convex part are in contact with each other, and Figure 2 (h) is a front view of the mold protrusion in which the insert is fitted. FIG. 2(a) is a sectional view taken along line II-II, and FIG. 3 is a vertical sectional view of the vicinity of a mold of a die-casting machine in which the present invention is implemented. 3φ...Fixed mold, 4...Fixed mold, 6...
Fixed nest, 7... Movable nest, 7b *** Convex portion, 21... Insert, 21a... Inner diameter, d
l... Short diameter of the oval on the insert side, dl...
...Longer diameter of the oval on the mold side.

Claims (1)

[Claims] The inner periphery of the insert and the outer periphery of the convex part of the mold into which this insert is fitted are each formed into a non-circular shape, and the minimum radius of the non-circular part on the insert side is the same as or larger than the maximum radius of the non-circular part on the mold side. A molding die insert movement prevention device characterized by being formed slightly smaller.