SU755587A1 - Casting mould for making polymer articles - Google Patents

Description

The invention relates to the processing of plastics into products.

Known mold for casting, containing a movable part with a matrix and ejector system and a fixed Gating plate with a spring-loaded cutter [1].

However, in a known mold, the separation of the inlet sprue from the product occurs when the mold is removed.

Closest to the invention is an injection mold for the manufacture of polymer products, containing a fixed gating plate, a movable matrix plate, a guide column placed in the matrix plate, a spring-loaded cutter and a mechanism for moving it [2).

In the well-known injection mold, a spring-loaded cutter is mounted on a plate mounted on a runner plate.

The disadvantages of the well-known injection molding are that the landing surface of the slug plate is contaminated with excess molding material from the nozzle of the machine and the sprue of the mold, which leads to jamming of the plate or reduction of its progress, and as a result of this

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incomplete separation of the sprue from the part, as well as the difficulty of controlling the magnitude and accuracy of the cutter plate, which depends on the adjustment of the stroke and the accuracy of the nozzle of the injection molding machine, which also reduces the reliability of the separation of the sprues from the parts.

The aim of the invention is to improve the reliability of the mold.

This goal is achieved by the fact that the mold for the manufacture of polymer products, containing a fixed gating plate, a movable matrix plate, a guide column placed in the matrix plate, a spring-loaded cutter and a mechanism for moving it, is provided with an intermediate plate with a ¹⁵ column guide lock in , and the mechanism for moving the spring-loaded slam is made in the form of a pneumatic cylinder placed in the intermediate plate with an output and input channel 20, on the piston of which is fixed tsekatel, equipped with a spool device, made in the form of a sleeve fixed in the matrix plate with a transverse through-hole and installed coaxially

755587

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a column hub fixed in a sprue plate and made with an annular groove, and an additional column housed in a sprue plate and made with a transverse through-hole for communicating the pneumatic cylinder cavity with the atmosphere.

FIG. 1 shows a mold in the initial closed position, a longitudinal section; in fig. 2 - the same in the working position; in fig. 3 - the same, in the open position; in fig. 4 - clipping on an enlarged scale.

The injection molding mold contains a fixed gating plate 1, a movable plate 2 of dies rigidly connected to the base 3, an intermediate plate 4, placed on the base plate 5 with ejectors of 6 products. In the intermediate plate there is a pneumatic cylinder 7 with inlet a and outlet b channels, the piston of which is made in the form of a plate-disk 8 with a cutter 9 rigidly fixed on it, spring loaded 10 and provided with a cutting edge 11 on the side of the sprues. the plate of the matrix of the sleeve 12 with a transverse through hole and installed coaxially with the sleeve of the column 13, mounted in the gating plate and made with an annular groove ά. An additional column 14 with a transverse through-hole e is installed in the gating plate to communicate the cavity of the pneumatic cylinder with the atmosphere. In the intermediate plate is an intermediate latch 15 of the guide column 16 installed in the matrix plate. In the gating plate is fixed thrust 17. In the sleeve 18, fixed in the 'push 5 pushers, installed pusher 19 gating system.

The mold works as follows.

In the closed state, material is injected into the mold cavity. At this time, the cut-off device 9 is in the extreme right (initial) position, since the air inlet channel a is blocked by the column 13, together with the sleeve 12. In this case, the transverse opening of the sleeve 12 is aligned with the channel a, and the groove of the column 21 is located behind the input channel a . In addition, the output channel b is communicated with the atmosphere by means of a through hole coinciding with it from an additional column 14.

When opening the mold (see Fig. 2), the movable part departs from the fixed part. There is a disconnection along the plane 1 - 1 between the intermediate 4 and gating 1 plates. At the same time, the intermediate plate 4 moves together with the movable part of the form, since the latch 15 is located in the groove of the guide column 16. When the intermediate plate moves, the input channel a joint

It is placed with a groove ά of the column 13. Compressed air from the line enters the cavity of the pneumatic cylinder. With the beginning of the movement of the intermediate plate, the output channel b is blocked by the column 14, and the width of the groove of the column 13 of the spool device is selected from the condition

B = 4 -k (MM)

where Mind is the speed of movement of the drop-down plates, mm / s;

ί - piston response time, s; K - coefficient taking into account the depth of the groove.

In this particular case, the width of the groove is 50 mm. During the movement of the intermediate plate 4, the piston 8 with the cut-offs 9 under the action of compressed air will move in the cavity of the pneumatic cylinder, overcoming the action of the spring 10, to the extreme left position. Cutting edges 11 cutoffs produce the separation of sprues from products. After the sprues are separated, the mold opens along the plane II — II between the plate of the dies 2 and the intermediate plate 4. This is due to the fact that the intermediate plate 4 is delayed by the rods 17, and the latches 15 disengage from the guide columns.

Upon further movement of the movable part of the form (see Fig. 3), the pusher 19 encounters the support of the machine and pushes the gating system, then the sleeve 18 encounters the support of the machine and stops the plates 5, and the plate of the dies 2 with the base 3 continues to move. There is a discharge of products from the matrix plate. When the mold is opened, the compressed air from the line is blocked by a sleeve 12. Then the mold is closed. The pressure in the pneumatic cylinder decreases, since its cavity communicates with the atmosphere through an opening from column 14, which is combined with the output channel b. Under the action of the spring 10, the piston 8 returns to its original position (rightmost until it stops). The cutters 9 open the gating channels for the passage of material into the design slots.

In the well-known mold, the reliability of separating the sprues from the parts is improved, achieved by eliminating the cases of jamming of the moving shut-off devices, as well as due to precise adjustment of the stroke of these knives. This leads to a qualitative removal of the gates.

Claims (1)

Claim Injection molding mold for the manufacture of polymer products containing a fixed gating plate, a movable matrix plate, a guide column placed in the matrix plate, a spring-loaded cutter and a mechanism for its movement, characterized in that, c. to increase 755587 reliability, it is equipped with an intermediate plate with a guide column disposed in a spring-loaded retainer; in the matrix plate of the sleeve with a transverse through hole and mounted coaxially with the column sleeve fixed in the sprue plate and made with an annular and additional column, placed in the gating plate and made with a transverse through hole for communication of the cavity of the pneumatic cylinder with the atmosphere.