RU2771995C1 - Wax injector - Google Patents

Abstract

FIELD: casting materials.

SUBSTANCE: invention relates to the technology of casting using melted models, in particular, to the production of wax castings by pressing molten wax into elastic molds and can be used in the jewelry industry, as well as in other industries using the technology of casting by melting models. The device contains a wax tank 1, a hollow fitting for injection of wax 2, the inner channel of which through the valve 3 communicates with the cavity of the wax tank 1, a chamber 5, a plate 4 for vacuuming the chamber 5 with a mold 8, a clamping mechanism 6 of the mold 8, a pressing device 9, a vacuum pump 14, a valve 15 for air intake into the chamber.

EFFECT: simplification of the design and the possibility of obtaining high-quality wax castings.

16 cl, 3 dwg

Description

Technical field

The invention relates to investment casting technology, in particular, to the production of wax castings by pressing melted wax into elastic molds and can be used in the jewelry industry, as well as in other industries using investment casting technology.

State of the art

From the prior art, a device for evacuating a mold and filling it with wax is known, consisting of a vacuum pump, a tank with molten wax, a fitting supplying wax to the mold, an elastic case into which the mold is placed, the cavity of which is connected to the vacuum line of the pump through three-position valve, means for vacuuming the canister with a mold, in the form of a disc mounted on the fitting. The mold is evacuated in an elastic case hermetically connected to a pressure disk mounted on a wax injection fitting (see Russian Federation patent RU 94006918 for an invention, publ. 10.04.1996).

The device works as follows.

The operator inserts the mold into the elastic case, the vacuum pump is switched on, the line of which communicates with the cavity of the case. The operator then manually attaches the mold case to the pressure plate on the wax injection nozzle so that the cone of the nozzle coincides with the funnel of the mold. The pencil case is sucked to the pressure disk, the mold is compressed by the elastic pencil case due to excessive external pressure. Next, the operator, by pressing the pencil case, shifts the fitting relative to its body and opens the channel for wax injection. During injection, the pumping of air by the vacuum pump does not stop.

The disadvantage of the known device is that it is not universal in relation to the size of the molds and does not have the ability to adjust the compression force of the molds, which can lead to compression or undercompression of the mold. This is especially true for product molds with thin, large surfaces.

Also, a disadvantage of the known device is that the pumping of air from the mold stops after the nozzle hermetically closes the filling funnel in the mold, which leads to a deterioration in the quality of wax castings.

From the prior art, a device for evacuating and filling molds with wax is known, consisting of a vacuum pump, a tank with molten wax, a fitting that supplies wax to the mold through a valve, a front plate movably and hermetically mounted relative to the fitting, a drive that moves the front plate along the axis of the fitting, a clamping device in which the mold is placed, containing a piston system for compressing the mold by supplying air with excess pressure into its working volume. The device evacuates the mold in a closed, rigid chamber prior to and during the supply of wax into the mold cavity (see US patent 6,065,954 for invention, publ. 05/23/2000).

The device works as follows.

The operator inserts the mold into the clamping chamber. Pressure is then applied to the piston system at the base of the mold compression device. After compression of the mold, the operator manually positions the clamp to align the center of the wax injection nozzle and the funnel of the mold. Presses the end of the clamping device against the front plate of the injector. After that, the vacuum pump is turned on, and the chamber with the mold is sucked to the front plate. It is assumed that at this moment the wax injection nozzle does not hermetically close the gate funnel in the mold, then the air is pumped out, after which the front plate with the chamber held on it by the vacuum is retracted by the drive so that the nozzle moves out of the front plate and hermetically closes the pouring funnel into press form. The wax is then injected into the mold cavity.

The disadvantage of the known device is that it has a complex design of pressing the mold to the wax supply fitting and is not universal in relation to the length of elastic molds, since the place of application of the compression force of the mold must be in a certain place for each mold , having a different length, in order to avoid pinching or under-compressing its front and rear parts, and in the specified device it cannot move along the line of the wax injection nozzle. This implies the replacement of previously used molds that are not suitable in size. This makes it difficult to apply it widely.

Also, a disadvantage of the known device is that the pumping of air from the mold stops after the nozzle hermetically closes the filling funnel in the mold, which leads to a deterioration in the quality of wax castings.

Disclosure of the essence of the invention

The purpose of the claimed invention is to develop a wax injector with a simpler and more reliable mechanism for pressing the mold to the end of the hollow wax supply fitting, universal in relation to the size of the molds, which is relevant, for example, in jewelry enterprises that have a large range of products and, accordingly, use molds for wax castings of different sizes.

The technical results of the claimed invention are:

- simplification of the design (no need for a complex mechanism with a pneumatic drive for pressing the mold to the end of the hollow wax supply fitting);

- the possibility of obtaining high quality wax castings by removing air from the cavity of the mold before and during the injection of wax into the mold.

- the possibility of using molds of various lengths.

The purpose and technical results of the claimed invention are achieved by creating a device for compression, evacuation of the mold and subsequent supply of molten wax into its cavity, containing:

- a hollow chamber with a hole in the body to accommodate the clamping mechanism with a mold and hermetic connection with a plate for evacuating the chamber with a mold;

- mold clamping mechanism placed in the chamber;

- tank for melted wax;

- a plate for evacuating the chamber with a mold having a hole for hermetic installation of a hollow fitting for supplying molten wax from the tank to the mold;

- a hollow fitting with a controlled valve in the internal channel for supplying molten wax from the tank to the mold after attaching the chamber to the plate and attaching the end of the hollow fitting to the filling funnel in the mold;

- a vacuum pump, connected by a vacuum line with the internal cavity of the chamber, for evacuating the chamber with the mold after attaching the chamber to the plate;

- a clamping mechanism for pressing relative to the chamber of the clamping mechanism with a mold towards the end of the hollow fitting, to ensure sealing of the end of the hollow fitting and the filling funnel in the mold;

- a valve for air inlet into the chamber to enable removal of the chamber from the plate after pouring the mold with melted wax;

- a controller with the ability to control turning the vacuum pump on and off, opening and closing the valve for supplying melted wax from the tank;

wherein:

- the mold clamping mechanism has the ability to move with the mold in the chamber along the longitudinal axis of the hollow fitting during the attachment of the chamber with the clamping mechanism and the mold located in it to the plate, for hermetic connection of the chamber with the plate;

- the hollow chamber is hermetically connected by a hole in the body with a plate for evacuating the chamber with a mold in such a place on the surface of the plate that the mold filling funnel is in the center of the longitudinal axis of the hollow fitting.

The plate for vacuuming the chamber with the mold is installed motionless relative to the hollow fitting, and the mold clamping mechanism is installed in the chamber with the mold preliminarily clamped in it, in the mode of pouring molten wax into the mold.

In particular embodiments, the mold clamping mechanism is capable of moving the compression force application point to the mold when the mold is clamped, and is configured to adjust the compression force of the mold.

In one of the private embodiments, the chamber is hermetically connected to the plate for vacuuming the chamber with a mold using, for example, elastic gaskets.

In another particular embodiment, the chamber is hermetically connected to the mold chamber evacuation plate by means of, for example, an elastic plate cover.

In one particular embodiment, the vacuum pump is connected by a vacuum line to the interior of the chamber through an opening in the chamber to evacuate the mold chamber.

In another particular embodiment, the vacuum pump is connected by a vacuum line to the internal cavity of the chamber through an opening in the plate for evacuating the chamber with the mold.

In private embodiments, the hollow fitting is made, for example, with a conical or spherical end.

In one of the private embodiments, the clamping mechanism is fixed, for example, in the inner cavity of the camera body.

In another particular embodiment, the clamping mechanism may be attached to, for example, a mold clamping mechanism.

In private embodiments, the clamping mechanism may be, for example, a spring mechanism or a pneumatic mechanism.

In one of the private embodiments, the valve for air inlet into the chamber is installed, for example, on the body of the chamber.

In another particular embodiment, the valve for air inlet into the chamber is installed, for example, on the vacuum line of the vacuum pump.

In a particular embodiment, at least one duct is cut into the mold to remove air from the mold cavity.

In one particular embodiment, the vacuum pump is capable of removing air from the mold cavity, for example, through at least one duct.

In another particular embodiment, the vacuum pump has the ability to remove air from the mold cavity, for example, through leaky joints of parts of the mold.

In private embodiments, the device additionally has a pressure sensor that measures the degree of air discharge in the chamber, and a system for monitoring the temperature of the melted wax in the tank.

Brief description of the drawings

The claimed invention is illustrated by the following figures.

In FIG. 1 schematically shows a particular example of the device in the working position (side view).

In FIG. 2a shows the position of the clamping mechanism with the mold in the chamber before being pressed against the plate for vacuuming the chamber with the mold (side view).

In FIG. 2b shows the position of the clamping mechanism with the mold in the chamber before being pressed against the plate for vacuuming the chamber with the mold (front view).

In FIG. 3 shows schematically one of the mold halves with an air duct cut into it.

In FIG. 1-3 shows the following:

1 - tank for melted wax;

2 - hollow fitting for supplying molten wax from the tank;

3 - controlled valve of the hollow fitting for supplying molten wax from the tank;

4 - plate for vacuuming the chamber with a mold;

5 - chamber for placing the clamping mechanism with the mold;

6 - mold clamping mechanism;

7, 10 - screw pair of the mold clamping mechanism;

8 - mold;

9 - clamping mechanism;

11 - pressure plate;

12 - air duct;

13 - elastic gasket;

14 - vacuum pump;

15 - valve for air inlet into the chamber;

16 - pressure sensor;

17 - filling funnel in the mold;

18 - part cast from wax;

19 - vacuum line of the vacuum pump.

Implementation of the invention

Wax injector (see Fig. 1-3) consists of a tank for molten wax 1; wax temperature control systems in the tank (not shown in the figure); a hollow fitting for wax injection 2, the inner channel of which is connected to the cavity of the tank 1 through a controlled valve 3; plate 4, fixed relative to the hollow fitting 2 for supplying molten wax from tank 1 to mold 8; chamber 5 with a hole in the body for accommodating the clamping mechanism 6 with a mold 8 and the clamping mechanism 9 to ensure that the clamping mechanism 6 with a mold 8 is pressed relative to the chamber 5 towards the end of the hollow fitting 2, to ensure the sealing of the end of the hollow fitting and filling funnels 17 in the mold 8; screw pair 7, 10 and pressure plate 11 as part of the clamping mechanism; vacuum pump 14 for evacuating the mold chamber; a valve 15 for letting air into the chamber 5 to allow the chamber 5 to be removed from the platen 4 after the mold 8 has been poured with molten wax; a controller (not shown in Fig.) that controls the activation of the vacuum pump 14, the opening and closing of the wax injection valve 3; pressure sensor 16, which measures the degree of air rarefaction in chamber 5. Plate 4 has a hole for hermetic installation of a hollow fitting 2 for supplying melted wax from tank 1 to mold 8 and is designed to close the hole in chamber 5 to seal the cavity of chamber 5. mold 8 is cut at least one air duct 12 to remove air from the cavity of the mold 8 (see Fig. 3).

In a private embodiment, the vacuum pump 14 is connected by a vacuum line 19 with the internal cavity of the chamber 5 through a hole in the plate 4 (see Fig. 1).

In another particular embodiment, the vacuum pump 14 can be communicated by a vacuum line with the internal cavity of the chamber through an opening in the chamber 5 (not shown in Fig.).

In a private embodiment, the chamber 5 is hermetically connected to the plate 4 using, for example, elastic gaskets 13 (see Fig. 1).

In another particular embodiment, the chamber 5 is hermetically connected to the plate 4 using, for example, an elastic coating of the plate 4 (shown in cross-hatching in the figure).

Hollow fitting 2 can be made, for example, with a conical or spherical end.

In private embodiments, as a clamping mechanism 9 can be used, for example, spring 9 or pneumatic (not shown in Fig.) mechanism. The clamping mechanism 9 can be fixed, for example, in the inner cavity of the body of the hollow chamber 5 or on the clamping mechanism 6 of the mold 8.

In one particular embodiment, the valve 15 for air inlet into the chamber 5 can be installed, for example, on the body of the chamber 5 (see Fig. 1).

In another particular embodiment, the valve 15 for air inlet into the chamber 5 can be installed, for example, on the vacuum line 19 of the vacuum pump 14.

In private embodiments, the pressure sensor 16 can be communicated, for example, by a hose with a vacuum line 19 of the vacuum pump 14 (see Fig. 1) or with the cavity of the chamber 5.

The camera 5 may have either a transparent housing, for example made of plastic, or an opaque housing.

The device, in a private embodiment (see Fig. 1-3), operates as follows.

The operator places the mold 8 in the clamping mechanism 6. He positions the screw pair 7, 10 in the center of the mold 8 and, using the screw 7, clamps the mold 8 with the required force. Then the operator sends a signal to the controller (not shown in Fig.) to start the operation of pouring molten wax from tank 1. The controller turns on the vacuum pump 14. After that, the operator inserts the clamping mechanism 6 with the mold 8 into the hollow chamber 5 through the hole in the hollow body chamber 5. Positions the chamber 5 with an open hole in the body relative to the plate 4 for vacuuming the chamber 5 with the mold 8 so that the filling funnel 17 of the mold 8 is in the center of the longitudinal axis of the hollow fitting 2 and completely presses the chamber 5 to the plate 4, which is sucked in and subsequently independently retained on the plate 4 due to excess external pressure. The chamber 5 is hermetically connected to the plate 4 using elastic gaskets 13. The clamping mechanism 6 with the mold 8 is pressed against the chamber 5 towards the end of the hollow fitting 2 and the end of the hollow fitting 2 is sealed relative to the filling funnel 17 in the mold 8 by clamping mechanism 9, after pressing the chamber 5 by the operator to the plate 4. After the pressure sensor 16 registers a certain degree of rarefaction of air in the chamber 5, the controller counts a certain pause required for the maximum possible removal of air by the vacuum pump 14 from the chamber 5 and the cavity of the press form 8, for example, through at least one air duct 12 in the mold 8. Then the controller sends a signal to open the valve 3 of the hollow fitting 2 and the molten wax from the tank 1 through the hollow fitting 2 fills the mold cavity 8 under the action of the pressure difference in the tank 1 and mold cavity 8. Next, the controller counts a certain pause required to fill the molds we 8 with molten wax, turns off the vacuum pump 14 and closes the valve 3 of the hollow fitting 2. After pouring the molten wax from the tank 1 into the mold 8, the operator opens the valve 15 to supply air to the chamber 5 and to the vacuum line 19 of the vacuum pump 14, removes chamber 5 from the plate 4, removes the clamping mechanism 6 of the mold 8 from the chamber 5, disassembles the mold 8 and removes the wax cast part 18 from the mold.

In the mold 8, one or more thin gas outlet channels 12 are pre-cut, thin enough so that the molten wax filling the cavity of the mold 8 has time to solidify in them without leaving the mold 8.

The clamping mechanism 6 of the mold 8 has the ability to move the point of application of the compression force to the mold 8 when clamping the mold 8 and adjust the compression force of the mold 8.

In a particular embodiment, the clamping mechanism 6 of the mold 8 has a groove for the screw pair 7, 10 for compressing the mold 8 (see Fig. 1), while the screw pair 7, 10 is movable in the groove of the clamping mechanism 6 mold 8 along the injection direction of the molten wax, providing a change in the place of application of the compression force to the mold 8.

Also, the wax injector can be made with auto-clamping - using a pneumatic mold clamping mechanism 8.

The wax injector can use molds of various sizes from elastic and hard materials.

It should be noted that the embodiments of the wax injector shown are not the only ones.

Although the claimed invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in the form and content of the claimed invention may be made therein without departing from the spirit and scope of the claimed invention, which are defined by the attached claims, taking into account the description and drawings.

Claims (28)

1. A device for compression, evacuation of the mold and subsequent supply of molten wax into its cavity, containing: - a hollow chamber with a hole in the body to accommodate the clamping mechanism with the mold and hermetic connection with the plate, for evacuating the chamber with the mold; - mold clamping mechanism placed in the chamber; - tank for melted wax; - a plate for evacuating the chamber with a mold having a hole for hermetic installation of a hollow fitting for supplying molten wax from the tank to the mold; - a hollow fitting with a controlled valve in the internal channel for supplying molten wax from the tank to the mold after attaching the chamber to the plate and attaching the end of the hollow fitting to the filling funnel in the mold; - a vacuum pump, connected by a vacuum line with the internal cavity of the chamber, for evacuating the chamber with the mold after attaching the chamber to the plate; - a clamping mechanism for pressing relative to the chamber of the clamping mechanism with the mold towards the end of the hollow fitting, to ensure sealing of the end of the hollow fitting and the filling funnel in the mold; - a valve for air inlet into the chamber to enable removal of the chamber from the plate after pouring the mold with melted wax; - a controller with the ability to control turning the vacuum pump on and off, opening and closing the valve for supplying melted wax from the tank; wherein: - the mold clamping mechanism has the ability to move with the mold in the chamber along the longitudinal axis of the hollow fitting during the attachment of the chamber with the clamping mechanism and the mold located in it to the plate, for hermetic connection of the chamber with the plate; - the hollow chamber is hermetically connected by a hole in the body with a plate for evacuating the chamber with a mold in such a place on the surface of the plate that the mold filling funnel is in the center of the longitudinal axis of the hollow fitting. 2. The apparatus of claim 1, wherein the mold clamping mechanism is capable of moving the compression force application point to the mold when the mold is clamped. 3. The apparatus of claim 2, wherein the mold clamping mechanism is configured to adjust the compression force of the mold. 4. The device according to claim 1, in which the plate for vacuuming the chamber with the mold is fixed relative to the hollow fitting. 5. The device according to claim. 1, in which the chamber is hermetically connected to the plate for evacuation of the chamber with the mold using, for example, elastic gaskets or an elastic cover of the plate. 6. The device according to claim 1, in which the vacuum pump is connected by a vacuum line with the internal cavity of the chamber through an opening in the chamber for evacuating the chamber with a mold or a hole in the plate. 7. The device according to claim. 1, in which the hollow fitting is made, for example, with a conical or spherical end. 8. The device according to claim. 1, in which the clamping mechanism is fixed, for example, in the inner cavity of the camera body. 9. The device according to claim. 1, in which the clamping mechanism is fixed, for example, to the clamping mechanism of the mold. 10. The device according to claim. 1, in which, for example, a spring mechanism is used as a clamping mechanism. 11. The device according to claim 1, in which, for example, a pneumatic mechanism is used as a clamping mechanism. 12. The device according to claim 1, in which at least one air duct is cut into the mold to remove air from the mold cavity. 13. Device according to claim. 1, in which the vacuum pump has the ability to remove air from the chamber and the mold cavity, for example, through at least one air duct, when the chamber is installed on the platen. 14. The device according to claim 1, in which the vacuum pump has the ability to remove air from the chamber and the cavity of the mold, for example, through leaky connections of parts of the mold, with the chamber installed on the platen. 15. The device according to paragraphs. 1-14, which has a pressure sensor that measures the degree of rarefaction of the air in the chamber. 16. The device according to paragraphs. 1-14, which has a temperature control system for the melted wax in the tank.

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