GB2039239A - Apparatus for manufacturing foundry cores - Google Patents

Abstract

Apparatus for feeding sand to a core box 26 includes a sand mixer 2 from which sand is supplied to a vertically movable chamber 6 containing a plunger 7, a valve gate 10 operated by means 12 and a nozzle 13 with a valve gate 14 operated by means 15. The plunger is driven by a ram 5 and the chamber is vertically moved by an actuator 3. With the chamber in the position shown sand passes from the mixer into the chamber, the volume supplied being dependent on the positions of the valve gates. On lowering the chamber its nozzle abuts the core box whereupon with the valve gates open the plunger is driven downwardly to force the sand into the core box. <IMAGE>

Description

SPECIFICATION Apparatus for manufacturing foundry cores The invention relates to foundries, and more particularly to apparatus for manufacturing foundry corns from fluid sand injected into core boxes.

The invention can be used in sanitary engineering, machine building, electrical engineering, automotive production plants and in various industries of mass or large-scale production.

In an apparatus for manufacturing foundry cores from fluid sands, comprising a support frame having mounted thereon a mixer and an actuator of mechanism for discharging and for moving a batching chamber, wherein the batch chamber incorporates a discharge plunger, a cylindrical nozzle secured to the bottom part of the batching chamber formed with a series of interconnected elements having a built-in gate, and a gate cylinder, it is provided in accordance with the invention that the actuator of the mechanism for the batching chamber has a double-action cylinder whose internal ram is rigidly connected to the discharge plunger, and the external ram, to the batching chamber built of interconnected parts with a gap, eg a groove or slot, at their connection, the gap receiving an additional, upper gate with a port, operable by an independent actuator.

It is advantageous to mount on the internal ram a device for adjusting the position of the plunger and to incorporate in the top head of the actuator of the mechanisms for the batching chamber a device for adjusting the position thereof, the top part of the batching chamber having a built-in port for access to the device adjusting the position of the pressing plunger.

According to a process embodying the invention, a fluid sand can be fed from a mixer to a batching chamber whose working volume is governed by the position of the gates and the adjusting devices. If the operation of the apparatus requires a largest possible volume of the batching chamber, the top gate is set open. Should a lesser volume of the batching chamber be necessary, it is the bottom gate which is set open.

The actuator makes a first stroke with the effect that the external ram descends, the moving chamber then reliably shutting off a discharge port of the mixer and being forced by the nozzle against a core box, this action cutting off sand in the batching chamber from that in the mixer. The gate operating in the given cycle then moves so that the axis of the port thereof aligns itself with that of the batching chamber. The actuator makes a second stroke to move the internal ram with the plunger downward and force sand from the batching chamber into a core box in a manner that the batching chamber and the nozzle are completely freed of sand.The batching chamber and the plunger then rise to the initial position, the core box is sealed and removed from the filling station, the working gate shutting off, and the batching chamber is filled with a fresh portion of sand through the mixer port. The corresponding gate is put into operation from a control desk, when re-converting the apparatus from one type of core to another in accordance with process conditions that require it. The corresponding gates in simultaneous manufacture of cores of different weights are actuated automatically as follows. A core box for manufacturing cores of lesser weight acts by a differentiating pin upon a pickup which energizes the top gate for a given cycle of operation, a small portion of sand then being accumulated in the batching chamber.When large cores are to be fabricated, corresponding core boxes act by a differentiating pin upon a different pickup which energizes the bottom gate for a given cycle of operation, a large portion of sand then being fed into the batching chamber.

If no sand is to be accumulated in the batching chamber, the batching chamber remains in the bottom position, the mixer port then being shut off as before.

The working volume of the batching chamber can be set for a small portion by adjusting devices on the internal ram and the top head of the actuator for moving the batching chamber and for discharging.

The batching chamber can be adjusted for a largeportion working volume, independently of the above adjustment, by setting the bottom gate at an appropriate height (through an adequate selection of the thickness of the nozzle elements), so that the aggregate volume of the batchiilhamber and of the part of the nozzle above the gate meets the required conditions.

Apparatus according to the invention can improve operational reliability, be of simple design, feature a high capacity, stabilize to a maximum possible degree the weight of cores and the magnitude of their internal canal, be rated to manufacture cores substantially differing in weight without reconverting the apparatus and fabricate various cores in a single simultaneous automatic production flow and, moreover, materially reduce the number of core boxes required.

A high accuracy of the adjustment of the batching chamber working volume eliminates sand waste and contributes to a self-cleaning of the batching chamber-nozzle system in the discharge process.

Features of the invention become readily apparent from one embodiment thereof which will now be described by way of example with reference to the accompanying drawing, in which: The Figure is a general cross-section of an apparatus of the invention for manufacturing foundry cores.

The apparatus comprises a support frame 1 having mounted thereon a mixer 2 and an actuator 3 for an actuating mechanism for discharging and for moving a batching chamber with an external ram 4 and an internal ram 5. The ram 4 carries the batching chamber 6, and the ram 5, a pressing or discharge plunger 7 built into the batching chamber 6. The batching chamber 6 consists of interconnected top and bottom parts 8 and 9 respectively, the gap therebetween accommodating a gate 10 with a port 11, actuated buy a cylinder 12. A nozzle 13, formed with interconnected elements having a built-in gate 14 actuated by a cylinder 15, is attached to the bottom part 9 of the batching chamber 6.

The mixer 2 is provided with a discharge port 16 and a bracket 17. With the chamber in the position shown, the port 16 is adjacent a port 18 of the batch ing chamber 6. The support frame 1 encloses a cage 19 with rollers 20 serving as guides of the batching chamber. The position of the pressing plunger 7 on the ram 5 is adjusted by an adjuster device 21, and that of the batching chamber 6 on a head 22 of the actuator 3, by an adjuster device 23. A port 24 provides access to the device 21. Beneath the nozzle 13 is shown an orifice 25 of a core box 26 which incorporates differentiating pins 27 or 28 acting respectively on pickups 29 or 30.

The present apparatus operates in the manner below.

Fluid sand is fed through the port 16 from the mixer 2 and through the port 18 into the batching chamber 6, the working volume thereof being controlled by the positions of the gates 10 and 14 and of the adjusting devices 21 and 23.

If the operation of the apparatus calls for a large volume of the batching chamber 6, the gate 10 is set in a position as shown where the axis of its port is aligned with that of the batching chamber 6.

Adjustment of a large volume is made by setting the gate 14 at an appropriate height (through suitable selection of the thickness of the nozzle elements), so that the aggregate vdltne of the batching chamber 6 and the part of the nozzle 13 above the gate 14 meets the required conditions.

If operations require a lesser volume of the batchings chamber 6, the port of the gate 14 is permanently aligned with the axis of the batching chamber 6, the adjustment for the smaller volume being performed jointly by the devices 21 and 23 independently of the initial adjustment.

The actuator 3 of the actuating mechanism makes a first stroke with the effect that the ram 4 descends, whereupon the batching chamber 6 shuts off the port 16 of the mixer 2, the nozzle 13 of the batching chamber 6 being forced against the core box 26, and the sand in the batching chamber 6 is then isolated from sand in the mixer 2. The gate selected for operation (depending on the volume, as explained) is moved by its cylinder into a position where the axis of its port aligns itself with the axis of the batching chamber port. The actuator 3 effects a second stroke with the effect that the ram 5 with the discharge or pressing plunger 7 descends to force sand from the batching chamber 6 into the core box 26 through the orifice 25.Next, the batching chamber 6 and the plunger 7 rise to their initial position, the core box 26 is sealed and removed from the pressing station, while the operating gate shuts off the batching chamber which is to be filled with a fresh portion of sand through the port 18. If the supply of sand to the batching chamber 6 is to be cut off, the batching chamber 6 remains, on command from a control desk, in the bottom position, the port 16 of the mixer 2 stays shut, and the automatic operation of the apparatus is not discontinued.

Energizing of a corresponding gate on conversion of the apparatus from the manufacture of one type of cores to another is effected from the control desk when a process need arises.

When cores of different weights are to be manufactured simultaneously on the apparatus, the corresponding gate is operated automatically in the manner below. A core box intended for fabricating cores of smaller weight signal its presence by action of a differentiating pin 27 thereof upon a pickup 29 which initiates a given cycle of operation of the gate 10, a smaller portion of sand then being fed into the batching chamber 6.

When cores of a large weight are required, a dif- ferentiating pin 28 of a core box acts upon a pickup 30 which puts into operation the gate 14 for a given cycle, a large portion of sand then being fed to the batching chamber 6.

Both the large and the small volumes of the batching chamber can be adjusted accurately and independently, and sand is expelled into a core box in totality, the pressing plunger 7 passing in the process through the batching chamber-nozzle system, cleaning it at every cycle.

The described apparatus provides a high capacity, produces cores of excellent quality, is simple in design, is rated to fabricate without reconversion cores differing substantially in weight and to manufacture various types of cores in a single production flow.

Claims (4)

1. An apparatus for manufacturing foundry cores from fluid sand, the apparatus comprising a support frame carrying a mixer and an actuator of mechanism for discharging and for moving a batching chamber; the batching chamber having a built-in discharge plunger and a cylindrical nozzle at the bottom part of the batching chamber formed with a bottom gate having a gate actuator; the batching chamber actuator having a double-action cylinder with an internal ram rigidly connected to the plunger, and an external ram, to the batching chamber, the chamber being formed with interconnected parts having a horizontal gap at their connection, said gap accommodating an additional, upper gate operable by an independent actuator.

2. An apparatus as claimed in Claim 1, wherein the internal ram carries a device for adjusting the position of the plunger, a top head of the actuator incorporates a device for adjusting the position of said batching chamber, and the top part of the batching chamber has a port for access to the device for adjusting the position of the plunger.

3. An apparatus substantially as hereinbefore described with reference to, and as shown in the accompanying drawings.

4. A foundry core made using an apparatus according to any previous Claim.