RU2029681C1 - Casting mold - Google Patents

Abstract

FIELD: polymeric material procession. SUBSTANCE: mold has the plate 6 with dies, the stationary built-up plate 1,2 with cavities for arranging the disc 15, having members for knocking out the pouring gates 16 and fingers 17. The disc 15 is mounted with possibility of limited axial motion. The fingers 17 have grooves for engaging with a ball-type stopper. EFFECT: enhanced efficiency. 1 cl, 4 dwg

Description

 The invention relates to the processing of polymeric materials in products of injection molding methods in an automatic mode with a complete separation of the product from the gate system.

 Known injection mold for the manufacture of polymeric products, containing a holder with matrices, a fixed runner plate with gates and reinforced in it rods for interaction with the holder, a movable plate with punches connected with a base plate, a gate with a gate delay, installed with limited movement in the base plate, the mechanism of rotation of the rod, the base, supports and eject system [1].

 The disadvantages of this form include the possibility of turning the undercut of the rod in a non-rotating central gate due to the high resistance of the peripheral undercut to the exit from the nests, which leads to disruption of the form.

 As the solution closest to the invention, an injection mold for the manufacture of polymeric products was selected, comprising a fixed sprue plate with undercuts for gripping sprues, a sprue sleeve with curved grooves in the form of helical grooves on the inner surface of the sleeve, a holder with dies and sprue nests, a movable punch holder with punches, ejector plates with ejectors, central movable core with undercut, fasteners and guides [2].

 The extraction of the undercuts holding the sprues when products in this form are torn off from them is carried out by turning the central sprue, equipped with curved helical protrusions when it is removed from the sprue sleeve. When the central gate is rotated, the lead gates are set in motion, at the ends of which there are undercuts to be removed from the nests with access at an angle to the plane of the gating plate.

 Successful extraction of undercuts can only be achieved if the strength and stiffness of the injection system are sufficient to overcome the resistance of the undercuts to the oblique exit from the nests. Otherwise, the rotation of the central gate will result in the separation of the inlet gate from the central gate or the curvature of the inlet gate without removing undercuts from the nests.

 In both cases, a malfunction of the form will occur. Strength and rigidity of the sprue system can be achieved only by increasing the size of the central sprue and the section of the inlet sprues, as well as by more significant cooling of the sprue system than would be required if there was no function to remove undercut from the slot.

 The disadvantage of this form is the unreliability of the method of extracting undercuts from the nests.

 The purpose of the invention is to increase the reliability of the form in work.

 The goal is achieved by the fact that the injection mold containing the matrix plate, a fixed gate plate with grips for holding the gate and rods for interaction with the matrix plate, a movable plate with punches connected to the base plate, the gate valve with curved grooves, a core with undercut installed with the possibility of limited axial movement in the base plate, is equipped with a disk with a gate ejector and fingers and a ball lock, moreover, the stationary gate plate is made integral with a cavity for placement action, the latter is mounted therein for limited axial movement, and the fingers are configured with grooves for cooperation with a ball detent.

 In FIG. 1 shows a mold in a fully closed position, a longitudinal section; in FIG. 2 - the same in the position of incomplete disclosure; in FIG. 3 - the same, in the position of full disclosure; in FIG. 4 is a section AA in FIG. 3.

 The proposed form contains a fixed sprue plate rigidly made of plates 1 and 2, in the plate 2 there are undercuts 3 for gripping the sprues, the sprue sleeve 4 with curved, screw-shaped grooves 5, plate 6, the movable plate 7 with punches 8, supports 9, plate 10, the base plate 11, the ejector plate 12 with the ejector 13 and the shank 14.

 In the cavity formed after joining the plates 1 and 2, a disk 15 is placed with the sprue 16 and fingers 17 rigidly fixed to it with grooves with the possibility of moving the disk in the cavity along the longitudinal axis of the mold.

 In the plate 6 of the matrix mounted ball retainer (figure 4), consisting of a ball 18, a spring 19, a cracker 20 and an adjusting bolt 21. The latch is fixed with a flange 22. The channel for accommodating the ball and the spring is made so that its downward movement under the action springs limited.

 In addition, restrictive rods 23 are rigidly attached to the fixed plate 1, and an undercut rod 24 is installed in the central part.

 The form works as follows.

 After casting the parts with the complete closure of the mold (Fig. 1), the matrix plate 6 with all subsequent plates departs from the plate 2 (the end of this stage is shown in Fig. 2). At the beginning of this stage, until the ball 18 has yet reached the groove on the finger 17 and moved along the outer surface of the finger, the plunger disk is not yet moving. During this period (Figs. 1 and 2), since the gate is connected to the plate 2 by the undercutting elements 3, it remains stationary and when the plate 6 moves, the product detaches from the gate. With further movement of the plate 6, the ball 18 enters the groove of the finger 17, communicates with it and carries it along. In this case, the disk 15 and the gates 16, which are rigidly connected with it, are moved, pushing the gates out of the undercut. At this point (Fig. 2), the disk 15 abuts against the opposite wall of the plate 2, the force on the ball-groove pair of the finger 17 increases, the spring 19 is activated, the plate 6 leaves the finger and goes to the left.

 At the end of this stage, the sprues are freed from communication with the products and plate 2 and connected to the central sprue with spreaders. The next stage of the form begins.

 By this moment, the rod 24, carried away by the plate 7, tears out the central sprue from the sprue sleeve 4 due to undercutting at the end and at the same time rotates the whole sprue system by a certain angle, since several grooves are made along the helical line on the inner surface of the sprue sleeve. The rotation of the system ensures that the sprues do not fall into the sprue nests of the plate 6 during subsequent convergence (figure 3).

 With further movement of the plate 10, the stroke of the plate 6 is limited by rods 23, and the rod with undercut 24, entraining the gating system, abuts against plate 6 (Fig. 3), undercut of the rod 24 breaks out of the central gate, it falls out of shape, plate 10 moves until a gap between plates 6 and 7 is formed sufficient to remove the products from the punches 8, the plate 10 stops, the pushers of the injection machine act on the shank 14 connected to the plates of the ejectors 11 and 12, the ejectors 13 are activated, removing the products from the punches 8.

 Reverse is performed in reverse order.

Claims (1)

 INJECTION FORM containing a matrix plate, a fixed gate plate with grippers for holding the gate and rods for interaction with the matrix plate, a movable plate with punches connected to the base plate, the gate valve with curved grooves, an undercut rod installed with the possibility of limited axial movement in a base plate, characterized in that, in order to increase the reliability of the mold in operation, it is equipped with a disk with a gate ejector and fingers and a ball lock, and the stationary gate plate in It is made integral with a cavity for placing the disk, the latter is installed in it with the possibility of limited axial movement, and the fingers are made with grooves for interacting with a ball retainer.

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