DE2145168A1 - Casting core - Google Patents

Description

Hamburg, the 6th “September 1971

Priority: Sep 7, 1970, Japan,

Pat.AnmoNr »78320A970

Applicant

KK Toyoda Jidoshokki Seisakusho
ΝΌ.1, 2-chome, Toyoda-maehi,
Kariya-shi, Aichi-ken, JAPAN

Cast - core

The invention relates to a composite cast core, which has a main or larger core part and at least one auxiliary or smaller core part attached thereto.

A composite core of this type is found in such pairs used in which a unitary core is difficult to manufacture and / or detach from the molded castings « In many other ought at least part of the core becomes independently and separately formed beforehand in the blow-in process and then in a suitable incision or a similar one Recess used, which is formed in the main core part to accommodate this! Part, whereupon the parts are firmly glued together will·

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Im! Pall manufacturing a cylinder block for a four-cylinder internal combustion engine is at least one Ke xnabschnitt for forming a bearing part of the engine together with a Main core part used to form the crankcase and a core for the cylinders. This core section consists of a pair of symmetrical core elements, which are separately blow molding and assembled to form a unit Inserted incision formed in the main core portion and glued to it to form a core assembly.

About the possibility of inserting the bearing core section and in order to ensure that the latter is securely adhered to the main core section, the recess must be provided for the receptacle of the bearing core part is provided with a high degree of precision using appropriate machines be incorporated. The gluing must be carried out with a considerable amount of skilled work.

When transporting such assembled cores, there is often the significant disadvantage that the bearing core section becomes detached from the main core body if the assembly is subjected to any impact Loosen the position and float in the molten metal of the casting of the cylinder cover . In addition, it is tedious and time consuming to remove the casting burrs

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and to eliminate joints on the castings in such Berexchen have formed which the fitting joints between the bearing core section and the main core body of the core assembly correspond"

The main aim of the invention is to provide an improved composite core in which the numerous known disadvantages which have been explained above "in v / essential are eliminated.

Another purpose of the invention is to provide an improved pattern assembly for making the improved one composite core according to the invention ©

The main aim of the invention is to provide an improved composite Kern zuhaffen, which is especially designed for the production of a cylinder block of a multi-cylinder internal combustion engine is suitable »Furthermore, an improved model arrangement for the production of the improved core created

A composite core according to the invention has a larger main core section and at least one smaller one Auxiliary core section and is characterized in that the smaller core section in the larger Keraabsohnitt embedded and firmly united with this by pouring and thermosetting.

A model arrangement according to the invention for producing a

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Such a core has a plurality of model parts which can be moved from a retracted out-of-use position into an advanced working position in which the parts form a closed model with a cavity for the blow-in process, the arrangement being characterized that at least one of the model members is provided with means that hold a smaller core portion in place within the cavity, _o

Other advantages and features of the invention will become apparent from the claims and from the following description and drawings, in which preferred embodiments of the invention, for example, described and illustrated are _e drawings:

Jig. 1 is a perspective view of an embodiment the core assembled according to the invention,

I ¹ Xg. 2 shows an axial section through the core according to FIG. 1 on a somewhat reduced scale,

I ¹ Xg ₀ 3 is an enlarged, exploded bottom pictorial view of a core portion which is part of the assembled core according to FIGS. 1 and 2 and suitable for casting an intermediate bearing part of a cylinder block casting.

Mg. 4 is a simplified top-down view of a model arrangement, which is suitable for the production of a composite core according to Fig. 1 and 3,

FIGS. 5 and 6 show two cross sections through the model arrangement according to FIG. 4, with the upper model element in FIG

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shown in his working position to shut off and to limit the ITorm space and in jig but is omitted to make the illustration too? simplify, and

Pig 7 shows a representation similar to FIG. 4 of a modified one Embodiment of the model arrangement,

1 and 2, a cast core 1 according to the invention is shown as an exemplary embodiment, which is provided for casting a cylinder block of a four-cylinder internal combustion engine Main or crankcase section 3, which are formed together in one piece.These essentially cylindrical projections 2a - 2d lie flush with one another and have the same shape and dimensions as they are used for forming the cylinder bores of the cylinder cover casting in cooperation with a main shape (not shown) required are. The group 2 of the cylinder bores forming sections and the section 3 for the formation of the crankcase are combined into a single rigid part which forms a main core body 4. This body 4 is combined with an Zwisohenkernabschnitt 5 for the bearing molding, which in! Ig. 1 and 2 only simplified and in I ¹ Ig. 3 is shown in detail.

As the number of cylinders in the engine increases, the Number of interim storage facilities increased accordingly. In such a case, which is not explained in more detail here, the number of core delegates naturally also be increased accordingly »

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Although in Fig. 2, the last-mentioned core section 5 only is shown in simplified form in one part, "it consists of two symmetrical core elements 5a and 5b, which are shown in FIG are illustrated somewhat moved apart for a better understanding »As can be assumed from Figo 1, are glued these core elements 5a and 5b along their mating surfaces The inner surfaces of the bearing core 5 assembled in this way form a mold space 6 for an intermediate bearing, such as Figo 3 shows the opposing inner surfaces of the core elements 5a and 5b designed so that they shape the sides of the bearing part of a cylinder cover which cooperate in the of the core 1 and a main form, not shown, is produced »

On the inner surface of the core element 5 a, a cylindrical projection 30 is formed, which is in firm engagement with a appropriately shaped and dimensioned recess, not shown, on the inner surface of the associated core element 5b can occur when the two core elements are put together to form a rigid unit 5 »see FIGS will"

The bearing core unit 5 is designed with lateral projections 7 and 7 ′, see FIGS. 1 and 3, around the core unit 5 in the model arrangement in their position, as before 4 and 5, FIG. 1 also shows, in a simplified and partially, a cast pipe 8 "

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The manner in which the casting core 1 is manufactured and a device for this is explained below with reference to FIGS. 4-6. 4 shows a mode arrangement 9 which is placed under a source of molding sand supply, preferably a filling box of a conventional core blow molding machine (not shown _). The model arrangement 9 has a plurality of metallic model members 10-16

The first model member 10 is practically a temporarily fixed metal block, which is formed with a plurality of vertical bores 17, in this case four, which are aligned along an axis ₀ Corresponding lateral shoulders 10a and 10b are formed on both ends of this block lower ends of the bores 17 are open per se, but usually closed by a removable closure strip 31. The means for fastening and removing the strip 31, preferably bolts and nuts, have not been shown in the drawing for the sake of simplicity The necessary guide and drive means, such as a pneumatically or hydraulically actuated piston-cylinder unit, are omitted from the drawing as known per se. In such a unit, the cylinder is preferably fixed, during the Piston is mechanically connected to the model member 10 by the piston rod, not shown. This movability

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iat duroii indicated by a double arrow A in FIG. 4.

The first model member 10 is provided with an axially extending Shallow recess 18 formed, which is used to shape the shoulder sections 5a and 3b on the main core part 3 *

A second and a third model element 11 and 12 are arranged so that they can be moved horizontally by corresponding pneumatic or hydraulic motors, not shown, as indicated by arrows B and C To delimit a Pormhohlraum _e On the inner surface 11a of the second mold member 11 is a surface 19 with ribs and depressions, which corresponds to the mold surface 4a for the end bearing in the cast core 1 ₀ The third model member is, although not shown in detail, on its inner surface provided with a correspondingly shaped surface «,

On the back of the model equipment, two model elements are arranged one above the other, the fourth and fifth model element 15 and 14, which can be moved independently of one another in the direction of arrow D by means of corresponding, not illustrated pneumatic or hydraulic piston-cylinder units are*

A front or sixth model member 15 is in the direction of arrow E in the same way by a pneumatic or hydraulic motor movable.

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The fifth model link is at a point between the two ends 14 with a recess 20 and the sixth model · · member formed with a recess 120 »These recesses 20 and 120 are used to form the corresponding lateral projections 7 'and 7 of an assembled bearing core portion 5 to be properly placed in the mold cavity of FIG Hold the model unit after assembly. Pig 6 shows in particular that the Pormglieder 13 and 15 with inward protruding rods 21 and 121 to form cast pipes These rods 21 and 121 are arranged and dimensioned in such a way that together they form the cast pipe 8 in the core 1 form during its manufacture

The fourth model member 13 is formed with an inwardly projecting, horizontally extending rod which is intended to form a corresponding cast pipe part _{not shown in Mg 6 1 and 2}

Am seventh or upper model link 16, see Pig. 4 »is provided with a pair of fixedly arranged lugs 24a and 24b which form the hollow interior spaces 23a and 23b in the core 1, see Pig. 2, a number of openings 25 of the upper member 16 are formed for blowing the material into the plate-like base part 16a, the insert out-of-position-cylinder unit KoIben is movable from its upper to the lower operating position by means of an unillustrated pneumatic or hydraulic · .di · Save-hardening · position can ale di "in Pig x 4 shown accepted" diethylene working position of the top 16 compared to Modtilgliedes

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the other links 10, 15 »14 and 15 are shown in Fig. 5 · each two thorns 124 protrude firmly from the lugs 24a and «24" b down * The injection holes 25 for the core material are connected to the molding sand supply source shown niolit, The Spikes 124 are concentric to the vertical .bores 17, although the upper model element 16 in FIG is shown offset.

In order to produce the core unit 1, which is shown in FIG. 1, all model members 10-16 are first in their out-of-use position brought and cleaned thoroughly and carefully so that impurities that sioh occasionally appear the interior or work surfaces of these parts will. The files are then sprayed with a solution of a common release agent, e.g. with silicone resin, polyvinyl alcohol, Paraffin or the like.

The first or lower model element 10 is then lifted pneumatically or hydraulically from its lower position into the upper working position, which is shown in FIG. 4. Thereafter the second * and the third model link 11 and «12 in brought the working position shown in Fig. 4 so that they come tight and flush with the shoulders 10a and 10b of the first member 10 in contact.

Then the front model member 15 and the rear model members 13 and 14 are moved in the direction of the center of the model arrangement moved forward, but the upper rear model

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link 13 compared to the rear lower model link 14-f see 4, is in a somewhat retracted position. Then the inverted core section 5 is used for the intermediate storage brewed in the intended position, "in which its lateral projections 7 and 7 'in engagement with the Recesses 20 or "120 are held. The initially retained member 13 is then in its final working position Finally, the upper model member 16 is moved downward toward the center of the model assembly moved and brought into its final working position. The relative position of these model elements 10-16 to one another and to the core section 5 is particularly shown in FIG 5 and 6 can be seen. The iiodell is thus completely closed .ds should be noted, however, that in Fig. 6 the Upper Liodell member 16 is not yet completely in its that idodell has been brought to the final position «,

The core section 5, which consists of a pair of core elements 5a and 5b lying next to one another, has been prepared separately in a conventional core manufacturing process, using correspondingly suitable molds and a conventional core-blowing machine. In the preferred embodiment, each of the core elements 5a and 5b has a concave outer side surface 5 ¹ , see FIG. 3, although in FIGS. 1 and 4 these outer surfaces are shown as flat surfaces for the sake of simplicity. The bottom surfaces of these core elements 5a and 5b will appear in the reverse arrangement in Fig. 4 and 6 above, in 5 ¹ O The reverse Kernabschnittatellung within the closed model unit

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from the members 10-16 is thereby secured that the parts 7 and 20 or 7 'and 120 enter firmly into engagement and that, in addition, between the upper surface of the fourth molded member 13 and the now upper surface 5 ^{1 of} the core elements 5a and 5b there is firm contact.

The preparatory work on the model including the Insertion of the core section 5 in the intended position in a practical embodiment only takes about 30 seconds.

The means for holding the core section 5 in its position can also have a different shape. In Fig. 7 is a modified one Embodiment illustrated for this purpose. A pair of tapered adjustment pins 26 are fixedly projecting from the top of the first model element 10 into the region of the cavity 18. In this case the core elements 5a and 5b formed with corresponding receiving openings, not shown, in order to flush these adjusting pins 26 to include »

After the core unit 1 is blow molded, the for Fixing used lateral projections 7, 7 'slightly cut off or the corresponding openings filled so that a complete and perfect core unit 1 is formed *

When the model members 10, 14 and 15 are in their working position for closing the model unit 9 »see FIGS. 5 and 6

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are brought, the mold or casting space 6 of the section 5 is tightly closed in that the model members 10, 14 and 15 the parts forming the outline of the core section 5 -tightly touch · This ensures that the core is made used material does not penetrate into room 6 during core production *

In order to further improve the sealing of the space 6, see FIG This independently movable part consists of a heat-insulating plate 27, a partition and support plate 28 made of asbestos or similar, heat-insensitive fiber material and a piston-like member 128, which is rigid with the parts 27 and 28 and via a rod 129 mechanically with a pneumatic or hydraulic piston-cylinder unit connected, which is not shown with »This cover unit consisting of parts 27» 28, 128 and 129 is slidably received in a recess 14a which is formed in the fifth model member 14, and in pressure contact in its Working position, see H ¹ Ig · 6, held with the right side of the core section 5

Section at the left side of Kernab 5 is a ähnliohe but acting capping oppositely provided from corresponding parts 27 'and 28', 128 'and 129' consists · This unit is received in a corresponding recess 15a beweglioh, in the front model element 15th

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is trained. The parts 27 ', 28' ', 128' and 129 'correspond essentially parts 27, 28, 128 and 129o

After closing the model unit 9 in the aforementioned The material forming the core shell is blown in from the supply source, which is preferably one not shown iUllkasten, which is arranged a little higher The injection takes place through the openings 25 into the Jorm cavity, which is delimited by the inner work surfaces of the model elements 10 - 16 »

An example of the material of the core shell has the following composition:

Quartz sand j

40 meshes 10 percent by weight

65 meshes 40 percent by weight

100 mesh 40 percent by weight

150 meshes 10 percent by weight

Total 100 percent by weight

Binder"

Phenolic resin 2.5 percent by weight, based on

aef sand

Harder: harder

Hexamethylenetetramine 15 percent by weight, based on the binder

Dispersant:

Calcium stearate 0.1 percent by weight, based on on sand.

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The inflation pressure was about 3 kg / om ₀

Wax completion of the Einblasformung the core unit 1 in the inner cavity of the model array 9, a heat-setting at about 250 ° - 300 ⁰ G made the injection and the Järmehärtun ^ sschritt extend over about 90 seconds, "K '-. X the". In the course of hardening, the model members 10-16 are equipped with electrical resistance means which are arranged in the interior of each diode element. 'This device, which is known per se, has not been shown Example total of 54 kV / have «,

After the end of the heat curing, the Mouelle unit is opened, by energizing the corresponding pneumatic or hydraulic piston-cylinder units to generate the Model members 10-16 from their working to the out-of-use position to move so that the]? form cavity is opened ,, Then the pot core unit 1, in which the inter mediate rnabschnitt 5 is rigidly embedded and effectively fixed in a non-severable manner by the thermosetting process, Around the rigid, baked-together connection of core section 5 removed from the open pattern setup and main core portion 4, the core portion 5 may preferably be formed with reverse wedge tapers be, preferably on each outer side surface of each of the elements 5a and 5b · In one example, the core unit the following main dimensions:

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- 16 ~ Overall length 480 mm 214516-8 Total height 410 mm Overall width 240 τη τη Height of the section
3 230 mm outer diameter
every jump 2 74 mm

Distance from center to
Middle between two adjacent cylinders 100 -. 120 mm

Bore of each cylinder of the casting approx. 74 mm

While blowing and noise curing within 90 Seconds has been completed in an example of the type described above, the models in- direction and removal of the core from it within 30 seconds

As mentioned, the core section 5 can preferably be reversed Wedge tapers, especially on the outer ones Side surfaces of the core elements 5a and 5b be formed · This becomes an otherwise possible solution of the section 5 from its embedded, baked-together position in the main body portion 3 during the molding process for the production of the metal casting or during the handling and transportation of the core unit 1 effectively prevented

The core unit 1 produced in this way has no disadvantages free gaps between sections 3 and 5 due to the tight, firmly bonded connection.

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turns out to be extremely reliable, accurate, and substantial permanent fastening of the bearing-forming section 5 within the main part 5β this arrangement is also particularly beneficial for preventing whiskers or gaps in the mold pieces that are using of the core unit 1 in connection with a suitable, not shown main mold «.

The invention is, as in the above description, very particularly advantageous for the production of a composite core unit 1 and applicable to a model means which are used for the production of a cylinder block of an internal combustion engine _0, the invention is not limited to this application but may used to solve similar casting problems

- PATENT CLAIMS -

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Claims (1)

-is- 2U5168 PATBiilASfSPHJOHJä Composite G-shaped core with a larger main core section and at least one smaller auxiliary core section, characterized in that the smaller core section (5) is embedded in the larger core section (3) and is "firmly" united with this by molding and baking together ο 2ο cast core according to claim 1 for the production of a common Cylinder cover gLi. "Piece of a multi-cylinder internal combustion engine, characterized in that the larger core section has a main core section (4) including one hollow, the lower crankcase forming part (3) and an upper, integrally formed hollow Core block (2) to form the cylinder and that the smaller core section (5) is an intermediate bearing forming Core is that has two essentially symmetrical core elements (5a, 5b), which are prefabricated and baked and are rigidly and firmly united by an adhesive connection between their separating surfaces 3ο model set-up for the production of a composite The core of claim 1 having a plurality of model. divide those from a withdrawn out-of-use position in their advanced working position, in which the model for the formation of an injection cavity is completed is, are movable, characterized ", at least 209811/1301 - 19 - - ¹ ^ - 2U5168 one of the model members (10-16) is formed with means (20, 120) around the smaller core section (5) inside to hold the mold cavity in position. 4 «, device according to claim 3», characterized in that the holding means have two oppositely arranged recesses (20, 120) in an oppositely arranged pair Has model members which take up the two ends (7, 7 ') of the smaller core section tightly and flush « 5 · Device according to claim 3 »characterized in that the means consist of pegs (26) which are fixedly arranged on a base member (10), the smaller core section (5) being designed with corresponding recesses for interacting with the pegs" ₀ 6. A device according to claim 3, characterized in that at least one opposing pair (14, 15) of the model members with cover members for covering of the portion is formed of a _# lOrmraumes the symmetrical between two elements of the smaller core portion is provided. 7β device according to claim 3 for producing a core according to claim 2, characterized in that at least one of the model members is formed with such a part which can come into contact with a part of the core portion forming the intermediate bearing to this in its position within the injection mold cavity of the device. 20981 1/1307