SU876262A1 - Injection mould for making low-melting patterns with undercut portions - Google Patents

Description

(54) PRESS FORM FOR MANUFACTURING EASY-MELTING MODELS WITH UNDERSTRUCTIONS

one

The invention relates to Foundry production, in particular, used in the manufacture of low-melting models with spherical cavities in the production of precision casting.

The closest rto technical essence and the achieved effect to the proposed is a mold for the manufacture of low-melting models with undercuts, containing a movable half-form with rods and elastic cores fixed on it, as well as a fixed half-form including a matrix and a plate with bushings 1.

In this well-known mold, the matrix is fixed and the plate with bushings is movable and connected to its movement mechanism, made in the form of a power cylinder. However, this design complicates the design of the mold, increases its dimensions and reduces the area of application, since the model mass is pressed into such a mold only along the parting line of the half-molds.

The purpose of the invention is to simplify the design of the speci-fop s, reducing its

dimensions, as well as the expansion of technological capabilities.

The goal is achieved by the fact that in a mold containing a movable half-form with cores with elastic cores fixed on it, a fixed half-form including a matrix and a plate with bushings, the latter is equipped with columns with restrictive shoulders, and the matrix is spring-loaded with the possibility of axial moving relative to the plate with sleeves in columns.

15

Fig, 1 shows a mold; fig 2. is the same at the time of disclosure.

The mold includes two half-molds, movable 1 and fixed 2, the movable half-mold contains a matrix 3 with a shaping cavity, a plate 4 with ejectors 5 in which rods 6 are installed, made two-stage with protruding tips (smaller stage) on which elastic cores 7 forming the internal cavities of models 8; cores 7 are barrel-shaped in the normal state

30 shapes and are made of an elastic material (preferably silicone rubber).

The fixed half-form contains a plate 9 with sleeves 10 fixed on it and columns 11 provided with restrictive shoulders, as well as a matrix 12 mounted with the possibility of relative movement along these columns. Between the die 12 and the plate 9, compression springs 3 are installed, the force of which is adjusted by threaded plugs 14. The bushings 10 and the rods 6 serve as the rods pl. making holes in models.

The inner diameter of the sleeves 10 is in conjunction with the diameter of the smaller step of the rods 6, and their number is determined by the number of models 8. On the plate 9, a centering sleeve 15 with a hole 16 is installed to press the model mass into the mold cavity.

Before pressing the model mass into the molding cavity, the mold is in a closed state. The elastic cores 7 are compressed by the rods 6 and the sleeves 10 with a force sufficient to impart a given configuration to them, while the matrix 12 is pressed against the plate 9.

After pressing the model mass into the cavity of the mold, carried out through the opening 16, and its subsequent curing, the movable half-form 1 is retracted to the left: together with it, the action of the energy of the springs 13 moves to the left relative to the fixed sleeves 10 of the matrix 12.

As the half-form 1 moves to the left, the distance between the ends of the rods 6 and the sleeves 10 increases, as a result of which the load is removed from the cores and the latter are straightened, partially out of the cavity of the models and take the initial configuration before compression. At that, the matrix 12, interacting with the limiting shoulders of the columns 11, stops.

The simultaneous movement of the matrices 3 and 12 at the moment of removal of the load from the cores and their removal from the cavity of the models prevents deformation of the latter.

Upon further movement of the mold 1 (the mold is fully opened), the plate 4, in contact with the stop (not shown), stops, and

 ejectors 5, slipping along the rods m 6, push the finished models 8 into the water bath.

The invention allows to reduce the size of the mold by 1.3-1.4 times,

5 and also to expand the technological capabilities of its application: the pressing-in of the model mass in the mold is possible both along the connector line of the half-form and along the axial line.

Claims (1)

1. USSR author's certificate number 442008, cl. B 22 D 17/22, 1975. and 12 3 g / / / /