SU1502373A1 - Machine for rotary moulding of articles from plastics - Google Patents

Abstract

The invention relates to equipment for processing plastics into articles and is intended for rotational molding of hollow articles from thermoplastic materials. The purpose of the invention is to simplify the design and reduce the energy intensity of the machine. To do this, the drives 25 and 26 of rotation of the centrifuges 2 are arranged parallel to the axis 22 of rotation of the rotary table 1. Drives 25 and 26 are mounted above the table 1 in the same radial plane by means of rotary levers with ends spring-loaded in the direction of rotation. Levers are located perpendicular to the radial plane. The input shafts 17 and 19 of the centrifuges 2 are parallel to the axis of rotation of the table 1 and are equipped with pulleys 23 and 24. The latter are connected to the drives 25 and 26 by means of endless flexible elements 29 and 30. To facilitate the reloading of the molds in the same radial plane with the drives 25 and 26 Additional drives 31 and 32 are rotated with gears 35 and 36. Shafts 17 and 19 are equipped with gears 37 and 38 for engagement with gears at the loading-unloading position after entry of pulleys 23 and 24 from engagement with flexible elements 29 and 30. 1 hp ff., 2 ill.

Description

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The invention relates to equipment for processing plastics into articles and is intended for rotational molding of hollow articles from thermoplastic materials.

The purpose of the invention is to simplify the design and reduce the energy consumption of the machine by reducing the number of rotary drives of the centrifuges and placing them outside the turntable.

FIG. 1 shows the proposed machine for rotational molding of plastic products; in fig. 2 - the same plan view.

A machine for rotational molding of a plastic product contains a driven rotary table 1, centrifuges 2 fixed on it to rotate forms 3 around two axes, equipped with a planetary gear with carrier in the form of a plug-holder 4, on which forms 3 fixedly mounted on the ends of spindles Near the table 1 is a two-position heating chamber 5 and a mold cooling chamber 6 and loading-unloading position 7 located in zone A.

The chambers 5 and 6 are equipped with louvered doors 8-10, a heating system 11 with an inlet 12 and an outlet 13, and a cooling system 14 with an entrance 15 and outlet 16.

Each centrifuge 2 is provided with a vertical input shaft 17 for supplying movement through a hollow shaft 18 to a fork-formholder 4 (horizontal axis of rotation of the forms) and a vertical input shaft 19 for transmitting movement through the internal shaft 20 to the rotation of the form 3 around its own axis (perpendicular) . Moreover, the transmission of movement to the hollow shaft 18 is accompanied by simultaneous transmission through the differential device 21 of equal movement to the internal shaft 20 in order to prevent relative planetary rotation of the forms around its own axis not from its drive

The input shafts 17 and 19 of the centrifuges are parallel to the axis 22 of the turntable of the rotary table 1 and are equipped respectively with pulleys 23 and 24 located at different levels relative to the rotary table 1.

The rotational drives 25 and 26 are arranged parallel to the axis of rotation of the turntable 1 and mounted over the latter in the same radial direction.

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Noah plane by means of the pivoting levers 27 and 28 with the ends twisted in the direction of rotation. The levers 27 and 28 are perpendicular to the radial plane. Drives 25 and 26 are connected to pulleys 23 and 24 by means of endless flexible elements — belts 29 and 30.

In the same radial plane with the rotational actuators 25 and 26, additional rotational actuators 31 and 32 are arranged to facilitate the reloading of the forms. The actuators 31 and 32 are mounted above the table 1 by means of the pivoting levers 33 and 34 with the ends springed in the direction of rotation. The levers 33 and 34 are perpendicular to the radial plane.

Additional drives 31 and 32 are provided with gear gears 35 and 36, and input shafts 17 and 19 are equipped with gear wheels 37 and 38 for engagement with gears at the loading-unloading position after pulleys 23 and 24 have left the engagement with endless belts 29 and 30 .

 The turntable 1 is equipped with a drive 39, operating in two modes - at operating speed and creeping, ensuring the turntable stops in a predetermined position.

The rotary molding machine operates as follows.

In Zone A, where the loading-unloading position 7 is located, the forms 3 are crushed and loaded with a predetermined amount of powdered thermoplastic, after which they are closed.

Before turning the table 1 to change the positions of the technological position of the forms 3, the louvered gate 8-10 opens and in the final position sends a command to turn the table. The actuator 39 is turned on and the table 1 rotates at the operating speed to the next position f

When a table approaches a predetermined position, its working speed changes to creeping and table 1 slowly moves and stops in the next position. In this case, the pulleys 23 and 24 of the centrifuge 2, which enters zone A, come out of interaction with the belts 29 and 30. As a result of this form, this centrifuge stops rotating, while its gears 37 and 38 enter into gear with the additional gears.

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drives 31 and 32, which allows the operator to produce (by means of jog buttons) turning the molds into predetermined positions for unloading finished products from the molds and loading them with new weights of powdered thermoplastic.

Loaded forms 3, which fall into position in zone B, begin to receive the necessary working movements, since the pulleys 23 and 24 of the centrifuge at this position interact with the belts 29 and 30.

After turning the table 1, the louvered door closes and the forms rotating in the heating chamber 5 are heated in zones B and C, and cooled in the cooling chamber 6 in zone D. Heating of the molds in the heating chamber 5 is provided by the heating system 11, which draws out exhaust air from the inlet 12, and through the outlet 13, heats the heated air into the chamber.

The cooling of the molds in the cooling chamber 6 is provided by the cooling system 14, which blows cold air through the inlet 15, and through the outlet 16 it is discharged into the atmosphere.

The heating process continues until the thermoplastic in forms 3 is completely melted, which takes place in two cycles at the positions of zones B and C, and the cooling process takes place only at the position of zone G before the product hardens.

Upon completion of the cooling of the molds 3 and the preparation of the molds at the loading and unloading position in zone A, the cycle is repeated in the sequence described.

The proposed device makes it possible to reduce the production area occupied by the machine by more than two times, simplify the design and reduce the weight of the centrifuges, reduce the number of motors of the centrifuge drives from sixteen to four (for

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four-point machine), to improve the service conditions of the machine when switching the rotation speeds of the molds.

Claims (2)

1. A machine for rotational molding of plastic products, comprising a driving rotary table, centrifuges fixed on it for rotating forms around two axes, with input shafts and rotational drives, stationary heating and cooling chambers stationary around the table and a loading and unloading position different from the fact that, in order to simplify the design and reduce the energy intensity of the machine, the rotational drives of the centrifuges are parallel to the axis of rotation of the rotary table and mounted above the latter in the same radial plane through ohm swivel arms with spring ends in the direction of rotation disposed perpendicularly to the radial plane, while the input shafts are arranged parallel to the axis of centrifuge rotation of the turntable and provided with pulleys, which are associated with corresponding rotary actuators through endless flexible elements. 2. Machine pop. 1, characterized in that, in order to facilitate re-charging of forms, it is equipped with additional rotational drives with gear gears located in the same radial plane with the available rotational drives and parallel mounted over the turntable by means of rotary levers with spring-loaded in the direction of rotation by the ends, and Gear wheels mounted on the input shafts of the centrifuges 5 to interact with the gears at the loading and unloading position after the pulleys have left the engagement with the flexible elements. 25 thirty 35 40