CN106170352B

CN106170352B - Slit is formed on the surface of core

Info

Publication number: CN106170352B
Application number: CN201580010307.2A
Authority: CN
Inventors: 文森特·莫尔洛
Original assignee: Montupet SA
Current assignee: Montupet SA
Priority date: 2014-02-25
Filing date: 2015-02-23
Publication date: 2018-04-06
Anticipated expiration: 2035-02-23
Also published as: FR3017811B1; JP2017506585A; WO2015128286A1; CN106170352A; EP3110582A1; MX2016011031A; FR3017811A1; KR20160132872A; US20160361759A1; CA2940314A1

Abstract

The present invention relates to the casting core for cast aluminium alloy gold part in a mold, the core includes moulding section, it is intended to and melting aluminum alloy contact, and it is intended to be positioned at least one non-forming part outside fusing aluminium alloy, this core includes at least one slit on the surface of core, and the slit extends at least one non-forming part so as to by caused gas is discharged into outside moulding section in the moulding section of core in casting process from moulding section.

Description

Slit is formed on the surface of core

Technical field

Field the present invention relates to casting and with aluminium alloy casting.

More specifically the present invention relates to in a mold with the casting core of aluminium alloy casting workpiece.Related core is special The mixture of sand and binding agent is not included.

Background technology

Casting core forms the part for manufacturing the mould of workpiece made of metal and especially aluminium alloy.

This core normally includes the mixture of sand particle and binding agent.Casting core can make being internally formed for workpiece recessed Enter portion.Thus it is completely or partially immersed in fusing metal.

When surrounding core by the aluminium alloy of fusing, air expansion, binding agent solvent evaporation and with temperature Rise the pressure that the phenomenon of they related burning will increase in core.The generation of this pressure is with the gas inside core Produce.Caused gas is most generally via enabling the hole of core that gas circulates to be dispersed into the outside of core.

When the pressure in core exceedes metallostatic pressure (height correlation with the metal above core), from core from The gas opened is injected into fusing metal, and this fusing metal encloses the gas.The phenomenon of gas discharge is led in fusing metal The presence of bubble is caused, this leaves hole in a metal after curing.This defect makes this workpiece brittle and has damaged its quality.

Even if bubble leaves from casting, discharge gas can also leave the vestige that they pass through in curing metal, and Porous aluminium sheet or the Crack Extension in bottoming region may also be had a responsibility for.

In addition, even if metal static limit pressure is not obtained considerably by the pressure inside core, gas can also be presented The vestige of body discharge.

Have been proposed attempting the solution for avoiding these drawbacks.

Attempt to increase the average-size of the sand particle in core in the past to improve the permeability of sand and via not by aluminium Part (in practice, core print) propelling gas of the core of covering is discharged into the outside of core.

But because the quantity of the resin bridges between particle is reduced, this technology makes core brittle.

Surveyed in addition, bulky grain is used for into core and the surface state of this workpiece is changed in such a way that on the surface of this workpiece The roughness of amount can damage their quality.Finally, this solution is related to the sand particle of several sizes in directing a factory, Which constitute extra inconvenience.

Another known trial, which is included between the outside for the core and mould being immersed in liquid metals to increase, to be contacted Form.Caused gas can be evacuated by these forms as blowdown stack in core.

This technology is widely used but needs to be limited in the different increases on casting and operate weight in the form of by these Newly plug the vacuum left：This workpiece is processed, increases one or more plungers to be closed again and allows to discharge and arrangement sealing control The shape of system processed.

In addition it is known that the closure gas suction catheter that manufacture is intended to increase in core negative pressure is produced with aspirating in core Raw gas and they are discharged into the outside of mould.The negative pressure in conduit is produced commonly by the suction of Venturi type.

This construction is fine implementation and its construction needs permanent control, and this constitutes drawback in itself.Especially, this type System must aspirate enough, the problem of to avoid gas from discharging, but can not aspirate too strongly to prevent in suction type core Metal.

In addition, the shape of core is generally less preferably suitable to their use.Their management and their maintenance represents skill The complication of art and economic order.

The different trials appeared in the gas discharge for solving the problems, such as core all expose limitation.

The purpose of the present invention is to eliminate these limitations.

The content of the invention

The present invention proposes the casting core for cast aluminium alloy gold part in a mold, and this core includes being intended to and fusing gold Belong to the moulding section of contact, and at least one non-forming part, it is intended to be positioned at outside fusing metal, this core is in core Include at least one slit on surface, and this slit extends at least one non-forming part to cast from moulding section Caused gas is discharged into outside moulding section in the moulding section of core during making.

The alternate technologies that the present invention proposes the simplification of prior art by making slit on the surface of core.These are narrow Groove forms the space for making the caused gas discharge in core, and at the same time slit is tiny enough to prevent aluminium alloy from entering They.By the preferred gas exhaust path for the non-forming part for being plotted to core, (the normally core outside fusing metal Seat), these slits discharged in the case where not being related to above-mentioned drawback may in core caused gas.

By using the invention also provides the following characteristics that independent or combination obtains：

Non-forming part is adapted for the core print being maintained at core in the appropriate location of mould inside；

Slit, which has, to be suitable to prevent from melting the width that aluminium alloy enters the slot；

Slit on the surface, which has, is less than 1mm and preferably 0.2mm width；

Slit has rectangle geometry, U-shaped or V-arrangement profile；

Slit has the mean depth between 0.2mm and 2mm, to allow the caused gas in the moulding section of core to exist Circulated in slit；

This slit is made up of laser；

Slit is manufactured by the instrument of the punch-pin with blade shapes.

The invention also provides a kind of mould for casting, and it includes all cores as the aforementioned.

This mould can also be narrow including being drawn into caused gas suitable for the suction by occurring at non-forming region Suction system in groove.

The invention also provides the method for manufacturing such as foregoing core, it is characterised in that including by laser in core Surface etch the slit the step of.

The invention also provides for manufacturing Al-alloy parts by casting fusing metal via previously described mould Method.

The last present invention proposes the cylinder for motor vehicle of the method acquisition by being previously described for manufacturing workpiece Lid, and the engine cylinder-body for motor vehicle.

Brief description of the drawings

Fig. 1 a show the core of the invention being immersed in fusing aluminium alloy in itself.

Fig. 1 b show the enlarged drawing of Fig. 1 a core.

Fig. 2 a show the side view of a part for the mould such as limited in the present invention and core, wherein moulding section It is immersed in fusing metal.

Fig. 2 b show Fig. 2 a viewed from above in the case of no mould core.

Fig. 3 a show the more accurate description of core of the present invention.

Fig. 3 b show the profile of the plane [AA '] along Fig. 3 a of the core limited in such as present invention.

Fig. 4 a show differently contoured (not necessarily in proportion) of slit.

Fig. 4 b show different types of slit, wherein, the flash of fusing metal enters these slots, and (not being must Strategic point is in proportion).

Fig. 5 shows the simplification figure of the plan on the surface of the core in the fusing metal being immersed in mould, has The possible circulation (arrow) in slit of caused gas in core.

Fig. 6 shows the progress of the gas discharge as the function of slit quantity.

Embodiment

Reference picture 1a, Fig. 1 b, Fig. 2 a, Fig. 2 b, Fig. 3 a, Fig. 3 b descriptions are according to core 10 of the invention.

Core 10 is suitable to the casting in mould 20.These castings are made up of aluminium alloy and are normally intended to use In automotive industry.These casting are generally used for engine cylinder-body or cylinder cover.

Core 10 includes being intended to the moulding section 11 contacted with fusing aluminium alloy 30.

Core 10 also includes being intended to be positioned at the non-forming part 12a outside fusing aluminium alloy 30.As a rule, core 10 Including the several non-forming part 12a separated particularly by moulding section 11.

Core 10 is arranged in the inside of mould 20 and the core print by being typically non-forming part 12a (referring to Fig. 2 a) 12b is immovably remained there.As a rule, mould 20 includes forming the mould bottom 21 of the bottom of mould 20, and works as At least one removable lipper 22 of the side wall of mould 20 is formed when lipper 22 closes.Mould bottom 21 forms casting with lipper 22 Outer shape.

Bottom 21 is further adapted for making core 10 motionless.For this purpose, core print 12b contacts with the lipper 22.

Core 10 includes at least one slit 13 being positioned on the surface of core 10.Slit 13 extends from moulding section 11 To at least non-forming part 12a and formed caused by gas preferred emission path with will in moulding section 11 caused gas Body is discharged into the outside of moulding section 11 and preferably then arrives non-forming part 12a (referring to Fig. 2 a, Fig. 2 b, Fig. 3 a, Fig. 3 b) Outside.

It is positioned on the surface of core 10 and at least one non-forming part 12a slit is extended to from moulding section 11 13 major function, be to be formed caused by gas preferred emission path caused gas will to be discharged into moulding section 11 Outside the moulding section 11.These gases can be dispersed into the part certain distance apart from core 10, and this will effectively be molded Workpiece to be manufactured.If slit 13 is positioned to contact with free air, their cans are accumulated at non-forming part 12, or Person is dispersed into outside these parts 12.

Each slit 13 includes the groove that moulding section 11 is connected to non-forming part 12a.Preferably, it is contemplated that type The moulding section 11 of the structure of core 10, i.e. core 10 is connected to two single non-forming part 12a, and slit 13 preferably passes through Two non-forming part 12a are connected through moulding section 11.

The geometrical property of slit

Reference picture 4a (by way of description, not to scale (NTS)), the profile of slit 13 are preferably rectangle, U-shaped or V Shape.These forms provide good folding between manufacture simplification and efficiency, i.e., caused gas circulation and the ability of discharge In.When the surface movement of its core 10 away from such as echelon type, profile expands so that easily circulation produces with discharge Gas and prevent fusing aluminium alloy 30 enter inside slit 13.Other profiles are also possible.

As a rule, the limitation related to fusing metal and generation gas of the size of slit is corresponding.The volume of slit 13 needs Optimize.

There is slit 13 width 13a to cause the aluminium alloy 30 of fusing does not produce on the surface of this workpiece after cooling to appoint What visible flash 31 (referring to Fig. 4 b).It must enter therefore, the aluminium alloy 3 of fusing must not enter the inside of slit 13 or its Enter less than the quality standard limited by regulation to set a distance.As a rule, the influence in the surface state of aluminium alloy needs Be the roughness of zero or casting value with without slit 13 in the case of do not change.This means optimized width 13a is so that the discharge for producing gas maximizes and minimizes flash 31.Optimize this width 13a to cause especially comparatively simple The volume of optimization slit 13 is easier in the situation of geometric profile.Width 13a is useful width, i.e., measured at surface (referring to Width 13a in Fig. 4 b).

Width 13a especially with aluminium alloy type function.

Normally, slit 13a width is less than 1mm and preferably less or equal to 0.2mm.

But those of skill in the art can adjust the width 13a of slit 13 to obtain aforementioned result.

Fig. 4 b show the flash 31 obtained for the different in width 13a of slit 13 (by way of description, not to scale (NTS)) It is differently contoured.

There is slit 13 mean depth 13b to allow caused gas in the inner loop of slit 13.The depth of slit 13 13b increases flash 31 without complexity, cost and the fragility for influenceing still core especially as depth 13b in theory.

In principle, it means that optimize the volume of slit 13 in the case of slit 13a constant width, so as to produce gas The discharge of body maximizes, and minimizes the manufacture complexity of slit 13 and limits the fragility of core 10.Fairly simple In the situation of geometric profile, the optimization of this volume will optimization mean depth 13b.

In practice, depth value 13b, which is more than 0.2mm, means that caused gas can be described in moulding section 12a The inner loop of slit 13.Preferably, and for the reason for described above, this depth 13b is more than 0.2mm and is less than 2mm.

The path of slit 13 is tracked to provide the preferred cycle path discharge production as much as possible for producing gas will pass through Angry body.Therefore, tracking plan is optimized to be advantageous to produce the circulation of gas with discharge with will be as caused by the gas Pressure limit to maximum.

Favourable tracking plan can be that is, true for example including the region with the minimum moulding section 11 without slit 13 Protecting on the surface of the moulding section 11 of core 13 does not have a little to be located at the distance more than prescribed limit value relative to nearest slit 13 Place.In the situation of several slits 13, it may be determined that the minimum and/or maximum spacing between slit 13.

Slit 13, or even more acute angles so preferably are tracked by expanding radius of curvature and limiting angle, To facilitate the circulation of caused gas and discharge (Fig. 3 a).

According to an embodiment, including at least two slits 13, the slit 13 is not intersected with each other, so that by slit 13 Whole given lengths covering surface maximize.

According to another embodiment, including at least two slits 13, intersected with each other selected else with offer of the slit 13 are followed Ring and preferably gas (Fig. 2 b) caused by discharge.

Because core print 12b already functions as non-forming part 12a, therefore non-forming part 12a advantageously core prints 12b。

But specific core 10 can be formed, wherein non-forming part 12a is not carried out as 12b and there are beneficial to generation The structure of the circulation of gas, such as branched structure.

Produce the evacuation of gas

Accommodating the non-forming part 12a of slit 13 includes being suitable to enable the caused gas in moulding section 11 (Fig. 2 a) The device 40 of discharge.These devices 40 can be made by different way.

Especially, device 40 can simply including non-forming part 12a slit 13 between fluidly connect 41 with it is small It is usual in the forced air of the certain volume of the pressure (this pressure is typically atmospheric pressure) of generation gas to be discharged, the volume Ground is much larger than the volume for producing gas.In mould 20 has situation of the bottom 21 with lipper 22, hole or opening in lipper 22 42 allow the connection 41 between non-forming part 12a (being typically core print 12b here) slit 13 and the volume of air.

Alternatively, device 40 also includes suction system 43 to be advantageous to the circulation of the caused gas in slit 13 (Fig. 5) With discharge.

The formation of slit

Slit 13 preferably is formed by laser.This technology is minimally invasive property and such that regardless of the complexity of core 10 Form also can be manufactured finely.

Also possibly these slits 13 are manufactured by special instrument, this instrument can include convex with blade shapes The device of mould (relief) (slit 13 obtains V-arrangement profile commonly by such a mode).

The example used

In instances, core 10 is arranged in mould 20 and the lipper 22 of mould 20 is fixed to by core print 12b.It is molten Change aluminium alloy 30 to be introduced into mould 20 and surround the moulding section 11 of core 10.Heat causes to produce gas inside core 10 Body.These gases preferably circulate via slit 13 and are discharged into non-forming part 12a (Fig. 4) so as to and then by discharge fills Put 40 discharges.There is no the vestige that gas discharges in this workpiece.The width 13a for such as properly selecting slit further avoid Flash 31 on the workpiece of cooling.

As a result compared with

Discharged using slit 13 by gas circulation caused by permission on core 10 and via preferable circulation route Contribute to reduce the pressure because in gas caused by the inside of core 10 to the outside of moulding section 11.

Fig. 6 shows the result of acquisition.

It is being referred to as the core with reference to " test block " (on the surface without the test block of slit 13) with being referred to as test " test It is compared between a series of cores of part ", each test block of this series includes 0.2mm width 13a in its surface Varying number slit 13.

Whole test blocks (including with reference to test block) have identical general geometrical shape all outside possible slit 13 And including identical material.

The use of pressure gauge is shown：

Decline for the test block of the series of tests including slit 13 relative to reference to gas discharge for test block 22%,

For the test block of the series of tests including two slits 13：Decline 40%,

And for the test block of the series of tests including 16 slits 13：Decline 46%.

Claims

1. one kind is used for the casting core (10) of the cast aluminium alloy gold part in mould (20), the casting core (10) includes：

Moulding section (11), it is used to contact with fusing aluminium alloy (30)；

At least one non-forming part (12a), it is used for the outside for being positioned at fusing aluminium alloy (30),

Characterized in that, the casting core (10) is included at least one slit on the surface of the casting core (10) (13), the slit (13) extends at least one non-forming part (12a) to cast from the moulding section (11) During in the moulding section (11) of the casting core (10) caused gas be discharged into the moulding section (11) It is outside.

2. casting core (10) according to claim 1, wherein the non-forming part (12a) is adapted for the cast moulding Core (10) is maintained at the core print (12b) of the internal appropriate position of the mould (20).

3. casting core (10) according to claim 1, it is suitable to prevent the melting aluminum wherein the slit (13) has Alloy (30) enters the internal width (13a) of the slit (13).

4. casting core (10) according to claim 1, it is less than wherein the slit (13) on said surface has 1mm width (13a).

5. casting core (10) according to claim 1, it is less than wherein the slit (13) on said surface has 0.2mm width (13a).

6. casting core (10) according to claim 1, wherein the slit (13) has rectangle geometry, U-shaped Or V-arrangement profile.

7. casting core (10) according to claim 1, wherein the slit (13) has putting down between 0.2mm and 2mm Equal depth (13b), to allow in the moulding section (11) of the casting core (10) caused gas in the slit (13) circulated in.

8. casting core (10) according to claim 1, wherein the slit (13) is made up of laser.

9. casting core (10) according to claim 1, wherein the slit (13) passes through the punch-pin with blade shapes It is processed into.

10. a kind of mould of suitably cast casting, including the casting core (10) according to any one of the claims.

11. mould according to claim 10, in addition to suction system (43), it is suitable to by the non-forming region The caused gas in the slit (13) is aspirated in the suction that (12a) occurs.

12. one kind is used for the method for manufacturing casting core according to any one of claim 1 to 9 (10), its feature exists In it is included by laser the slit (13) are etched on the surface of the casting core (10) the step of.

A kind of 13. method for manufacturing Al-alloy parts by casting fusing metal by means of mould according to claim 10.