SU802043A1 - Mould for polymeric articles,with breaking-off spot gates - Google Patents

Description

one

The invention relates to the field of plastics processing in products, in particular, to devices for the manufacture of products with a high-quality external surface, namely sprues.

A casting mold with a gating system located in the additional plane of the connector and point inlet channels is known, comprising a fixed part with a mounting plate, a spring-loaded casing of the matrices and a central ejector of the gating system and a moving part with punches and a colliding plate provided with a bracket with an emphasis mounted on t ge fixed in the mounting plate l.

Such a form does not ensure the reliability of ejection of the LITNIC system cut off from the products, since when casting with a central sprue, a thin thread is periodically pulled out, which can be torn off only by instantly separating the gating system from the gating plate of the mold.

At the same time, the delay of the gating system only by the central part does not ensure the reliability of its removal

account of formed gravy, burrs.

The closest technical solution to the described one is a casting mold for polymer products with the separation of pin gates, containing a fixed mold with delay and gates, a moving mold, including a spring-loaded relatively

0 fixed plate relief plate and gating plate associated with the matrix plate t2.

In a known form, the force of the spring must be constantly greater than the force

5 with which the sprues are hooked with delays. During operation, the spring loses its elasticity, which reduces the reliability of the form.

The purpose of the invention is to improve the reliability of the form.

The goal is achieved by the fact that the injection mold for polymer products with the separation of pin gates, containing a fixed mold with 5 gate delays, a movable mold, including a spring loaded relative to the fixed plate, and that gating plate connected to the matrix plate, according to invention, equipped with stops fixed

on the relief plate and the gating plate, and the earring placed on the stops, the bar of which is made with expanding areas at its ends and with a length less than the displacement of the gating plate.

Fig, 1 shows the shape, section; in fig. 2 - form in the open position; in fig. 3 is a view along arrow A in FIG. one; in fig. 4 is a view of the earring along arrow B in FIG. one; in fig. 5 shows the position of the stops in the shackle at the moment of incomplete removal of the relief plate from the fixed plate; in fig. 6 is a view of an earring along arrow B in FIG. five.

The casting mold contains a fixed half-form 1 with a delay of 2 liters and a movable half-form including a discharge plate 3 sprues spring-loaded relative to the fixed plate, a sprue plate 4 connected to the matrix plate 5 by the clutch mechanism 6, the product ejector plate 7 and the base 8. In the fixed plate reinforced guide columns 9 and limiters 10 and 11, plates 3 and 4, respectively.

The ejection plate 3 is connected to the gating plate by means of the earring 12, which is placed on the stops 13 attached to these plates.

The groove of the earring is made with expansion sections at its ends, and its length is less than the magnitude of movement of the gating plate.

Casting form works following | in a way.

After injection of the material into the molding cavity and the corresponding shutter speed, the form is opened, the movable part of the form departs from the stationary. Initially, the mold opens in a plane between the relief plate 3 and the sprue plate 4. At this point, the sprues due to the delays 2 are detached from the products. Under the action of the springs 14, the discharge plate moves away from the fixed plate and, overcoming the resistance of the gating system, disrupts the sprues from delays 2. And the disruption of the sprues from the delays is promoted by the force created by the earring, since at this moment the stops 13 fixed to the plates 3 and 4 they are located in the extended parts of the groove of the earring, and the plate 4, while continuing to move, acts through the earring on the discharge plate 3, carrying it along with it.

After overcoming the resistance of the gates, the discharge plate 3 abruptly picks up speed.

However, the speed of movement of the gating plate 4 associated with the plate of the matrix 5 by the clutch mechanism is insignificant compared to the speed of the ejection plate after the release of delays from the gates. Due to the considerable speed of the relief plate, its stop enters a narrow part of the groove of the earring and advances it in the direction of movement of the relief plate, while the support of the runner plate also enters the narrow part of the groove of the earring.

Since the width of the narrow part of the groove of the earring is smaller than the diameter of the stops, as the relief plate continues to protrude, the stops are jammed in the earring (this position is shown in Fig. 5 and b). Thereafter, the reset plate abuts against the stops 10 and stops.

Upon further disclosure of the form, choosing the stroke on the stopper 11, the gating plate stops and the matrix 5 plate connected to the base 8 continues to move, and the coupling mechanism 6 operates. The form shank hits the machine stop, the ejector plates 7 stop, and the matrix plate with the base continue to move.

The articles are pushed out of the molding cavities, after which the mold begins to close, and the cycle repeats.

Claims (2)

1. USSR author's certificate number 448958, cl. B 29 C 5/00, 1973. 2. Zavgorodniy V. K. Mechanization and automation of plastics processing. M., Mechanical Engineering, 1964, p. 451-453, p. 274 (prototype) 6 View 6 FIG.