CN1165396C - Device for hardening foundry cores - Google Patents

Abstract

The present invention relates to a device for hardening cast cores made of substances containing sand, wherein in a core-forming tool, a core to be hardened is exposed into an airflow enriched with a catalyst, and if necessary, the core to be hardened is exposed into a compressed airflow. The device comprises a mixing section (1) which can be connected to the front side of the core-forming tool in order to generate a carrier gas mixture of a catalyst stream. The mixing section is in flow connection with a catalyst receiving container (5) and a program controlled compressed air source (6) by a program controlled valve (2), a pump (3) and a flow meter (4), wherein the valve (2) in a first operation tube of the receiving container (5) can be temporarily switched to the return pipe (8) of the receiving container (5) so as to balance pressure generated in a first operation system. In addition, the mixing section (1) comprises a block-shaped evaporator element (9) made of porous ceramics.

Description

The apparatus and method of hardening foundry cores

The present invention relates to the device of a kind of sclerosis by the casting core that contains sand material system, wherein the core that will harden in the core mould is exposed in the gas stream of enrichment catalyst, if desired, then be exposed in the compressed air stream, the mixer in order to produce catalyst gas vector gas mixture that can be connected core mould front reaches with the catalyst receiving vessel by sequencing valve device, pump installation and flowmeter and is connected with program control compressed air source and course.

This class device is known; For example they provide so-called ice chest casting technique, the component of wherein adding two kinds of artificial resin systems in core sand, a kind of amine, for example alkylamine or methyl formate one are added into as catalyst, harden with sand with that.At this moment, a kind of component for example is the artificial resin of the liquid consistency of mylar, polyethers or any band reaction hydroxyl; Second kind of component all is organic isocyanate in all cases.Two kinds of components are fully mixed moulding then with molding sand.Do various effort then with catalytic reaction and control the particularly safe handling of amine.

Known compression alkyl amine and the AIR MIXTURES of passing through isocyanate resin one sand mixture for a long time, thus, this amine one air mixture is heated to 30-50 ℃ of temperature and drips so that evaporate all amine.

But it is the hardening process cost plenty of time that already known processes has drawbacks common.For example, the demoulding of mould SMIS sand mixture is often only used part second on core shooter; And be that the gasification that the sclerosis core is followed need be kept several seconds.Natural result is that gasification is very expensive.

For reducing gasification time or firm time, usually, custom is added excessive amine, and danger that adhesive dissolves again can take place for this, and the possible final strength of core rod is reduced to about 80-85% like this.

Below, another known technology is to use dispensing pump between catalyst source and vector gas and catalyst mix place, in order to distribute catalyst better.But this can only produce unsatisfied result, because initial and each distributional effects is irrelevant fully at first pressure condition in service of catalyst.

Then, good slightly result is reached, wherein catalyst gas vector gas mixture and compressed air temporarily are stored in the dispense container respectively, then from these dispense container with suddenly continuous air blowing with their injections to core, compressed air is stored by big capacity thus, and is heated to than the higher temperature of catalyst gas vector gas mixture situation.

But the technical fee of these methods is very big, and such device does not almost change.

So we add in the spout of bringing-up section front for the production of the catalyst gas vector gas mixture liquid form with catalyst in suggestion, thus, by other jet-stream wind by this spout effect, its exit flow atomizing.

But this device is only with very inaccurate distribution gasification.

Therefore, the objective of the invention is to create a kind of device that distributes required catalyst with losing heart most time optimal, simultaneously, use has the various technologies of various parameters, for example continuously pressurized segment or proportional pressure increase, with the catalyst gas of different amounts and random time to vector gas or compressed-air actuated the inflation.

Be that the valve in the first operation pipe of receiving vessel can temporarily be transformed into the recurrent canal of receiving vessel, so that produce pressure balance in first operational system according to what the present invention at first reached.At first, this method guarantees to distribute more accurately, because now can keep definitely constant at the catalyst first operating pressure condition, carries out each batch operation after the pressure balance in advance in all cases.

According to the technology of the present invention, the residue switch of program-controlled valve and this device and the conversion separately of control element.

We find, allow to distribute more accurately catalyst prior to each batch operation when the catalyst first operating pressure balance, but also will consider to provide improved scope, particularly about reducing the consumption of each catalysts.

At present accessible according to the present invention is that wherein mixer comprises the piece type evaporator element by porous ceramics system.

We find that porous ceramics has very big inner surface, it is moistening by the catalyst gas fully, thereby suppressed by vector gas stream is moistening, and air is exposed to and the contacting of wetted surface fullest usually, make catalyst the best be discharged to core like this, make the corresponding reduction of catalyst amount.

In addition, it is important that match with a large amount of air streams by ceramic evaporator, catalyst is transferred to core and taken place gradually, so that remaining amine also reaches core when it hardens, improves its case hardness so greatly.

This ceramic evaporator can comprise carborundum, aluminium oxide, zirconia or zirconium carbide, and can plate the chromium nickel with activity.

It is through-flow can to exist in pressurized segment or along with ratio pressure increases and exists.

Find that in addition with a kind of like this ceramic body in magnetic field, catalyst can additionally be activated, its consumption can further reduce.As a result, according to the present invention, on piece type ceramic component, can provide a permanent magnet.But enrichment iron oxide in this ceramic body.

Accompanying drawing 1 is the block diagram of the device of hardening foundry cores of the present invention.

Narrate the embodiment of the object of the invention below in more detail by means of accompanying drawing, accompanying drawing is described the device of hardening foundry cores with block diagram.

Shown sclerosis contains the device of the casting core of sand material system, it can be connected with the core mould 10 (not being shown specifically) of a core shooter, at first this device comprises a mixer 1, it is mixing arrangement 1, it makes generation catalyst gas vector gas mixture before can be placed in mould 10, and it links to each other by sequencing valve 2, pump 3 and flowmeter 4 streams with catalyst receiving vessel 5 and program control compressed air source 6.These constructional devices and other device, as fluid heater 11 with can be connected temp probe 12 after the mixer, by control section 13, promptly control device 13 is by program control.

According to the present invention, as mentioned above, the valve 2 in the first operation pipe 7 of receiving vessel 5 can temporarily be transformed into the recurrent canal 8 to receiving vessel 5, so that produce pressure balance in first operational system.

In addition, according to the present invention, mixer 1 comprises the piece type evaporator element 9 of porous ceramics system; This evaporimeter can comprise carborundum, aluminium oxide, zirconia or zirconium carbide, and can plate with active chromium nickel.

In addition, on this ceramic body 9, permanent magnet 14 is effective.

By described pressure balance, distributing valve 2 is changed by control section 13 according to the signal of flowmeter 4 or by the time correlation method, and thus, catalyst reaches mixer.Simultaneously or then, add and transport air, mix then, if suitablely guide to core by fluid heater 11.If desired, can supply with purify air thereafter.

At first, this method guarantees the distribution of high precision, because the pressure condition in the catalyst first operation pipe 7 can keep definitely constant, carries out each batch operation after the preestablished pressure balance in all cases.In addition, the porous ceramics evaporimeter allows the catalyst optimum discharge to core, so catalyst amount significantly reduces as mentioned above.In addition, match with a large amount of air streams by ceramic evaporator, catalyst takes place gradually to the transfer of core, so that residue amine still reaches core when it hardens.This improves the case hardness of core widely.

Claims (8)

1, a kind of device that is hardened in the core material that contains sand in the casting core mould, comprising:

Mixing arrangement, this device are connected with the core mould and are used for the vector gas stream of enrichment catalyst gas is introduced the described core material that contains sand;

First operational system, this system comprise that a receiving vessel that contains catalyst, first operation pipe that is connected with described receiving vessel and described mixing arrangement, one are arranged in the first operation pipe and are used for catalyst extracted out pump by the first operation pipe, is arranged on the first operation pipe and is used for that catalyst is assigned to the valve gear of described mixing arrangement and one by described receiving vessel being arranged in the first operation pipe and the flowmeter between described pump and described valve gear;

Compressed air source, this compressed air source are connected with described mixing arrangement and the vector gas stream that is used for containing air is fed to this mixing arrangement; And

Program control device, this device are used to control the valve gear and the described compressed air source of described first operational system;

Wherein can temporarily the valve gear that is arranged in the first operation pipe be used as the recurrent canal that feeds receiving vessel by described program control device.

2, according to the device of claim 1, the core material that wherein contains sand is exposed to compressed air stream after being exposed to the vector gas stream of enrichment catalyst gas.

3, according to the device of claim 1, wherein mixing arrangement comprises a piece type evaporator element by porous ceramics system.

4, according to the device of claim 3, wherein said evaporator element is coated with active chromium nickel.

5, according to the device of claim 3, the porous ceramics enrichment iron oxide of wherein said evaporator element.

6, according to the device of claim 5, wherein mixing arrangement further comprises the permanent magnet that is positioned on the evaporator element, makes permanent magnet produce magnetic field for the evaporator element of enrichment iron oxide.

7, according to the device of claim 3, wherein said porous ceramics comprises the ceramic material that is selected from carborundum, aluminium oxide, zirconia or zirconium carbide.

8, the method for the casting core in a kind of core mould that is hardened in core shooter comprises:

Described core mould is connected with device according to claim 1, and

Use described device to be hardened in casting core in the described core mould.