WO2020187573A1

WO2020187573A1 - Water jacket core

Info

Publication number: WO2020187573A1
Application number: PCT/EP2020/055739
Authority: WO
Inventors: Siegfried Heinrich
Original assignee: Schaufler Tooling GmbH & Co. KG
Priority date: 2019-03-15
Filing date: 2020-03-04
Publication date: 2020-09-24
Also published as: DE102019106643A1

Abstract

The invention relates to a method for producing a water jacket core (48), said method comprising the following steps: a. introducing structures into at least two separate water jacket core segments (102, 104, 106, 108, 110) to form cooling channel portions; and b. joining the water jacket core segments to obtain a water jacket core having at least one cooling channel (64, 66, 68).

Description

Title: Water jacket core

description

The invention relates to a method for manufacturing a water jacket core. The invention also relates to an associated water jacket core and an associated method for producing a cylinder block

Motor housing. Cylinder blocks (also called "engine blocks") have

Regardless of how they are manufactured, a cylinder wall with an inside along which the piston of a fully assembled engine can slide up and down. The inside of the cylinder wall can be a surface created by machining a cast part, and that too can be coated, or the inside of the cylinder wall is formed by the inside of a bushing which is cast into a casting. The cylinder wall is from

Cooling water channels (also called "water jackets") are surrounded by an outer wall of the

Cylinder blocks are limited. The water jacket is flushed with water when the engine is running in order to ensure that the engine block is cooled around the cylinders. A cylinder block of the "open-deck" type is free of undercuts, at least in the area of the water jacket, that is to say does not have any cast-in material sections between the cylinder wall and an outer wall. Thus, such a cylinder block can be manufactured as an inexpensive die-cast part. In order to form the water jacket, a water jacket core is inserted into the die casting mold. In the case of series blocks, this is usually part of the main use of the

movable mold surface, used in V-blocks as a partial insert in the slide attachment of the inclined slide.

The water jacket core is usually made of hot-work steel (1.2343, 1.2344, 1.2367 or comparable high-purity special grades). Due to the lack of space, conventional cooling cannot be introduced into the comparatively thin walls, which leads to strong heating during the filling process during die casting when the water jacket core is in operation. After partial removal, the

The water jacket core is therefore cooled down to a correspondingly large extent by usually water-based release agents, which happens in particular in a spray process. This leads to comparatively strong changes between pressure and tensile stresses. This results in a moderate service life of a water jacket core of typically 10,000 to 20,000 casting cycles.

Despite the comparatively thin wall thicknesses, a

To provide cooling, a 3D metal printing process (also called powder bed process) has become known. Freely configurable cooling channels can be produced in the printed water jacket core. However, the cost of these water jacket cores is at least three times that of a conventional one

Water jacket core, so that economic efficiency is hardly given even with a significant increase in service life.

On the other hand, the introduction of so-called "jet coolings" in the form of thin stitch cooling has become known.

However, such stitch cooling is only available in

comparatively thick wall sections of a water jacket core can be introduced. Most of the water jacket core, on the other hand, remains uncooled, so that the local cooling can even increase the voltage peaks in the course of a production cycle, which leads to a continued moderate service life of the water jacket core.

The invention is therefore based on the object of remedying the stated disadvantages of the prior art.

This object is initially achieved by a method having the features of claim 1. Accordingly, a method for manufacturing a water jacket core is proposed. This includes

Do the following steps:

a. Introduction of structures for the training of

Cooling channel sections in at least two separate

Water jacket core sections; and

b. Join the water jacket core sections to make a

Water jacket core with at least one cooling channel

receive .

The structures can in particular be introduced on the joining surfaces of the water jacket core sections. After the structures have been introduced, the

Water jacket core sections are joined in order to obtain a total, in particular one-piece, water jacket core with at least one cooling channel.

There are initially two separate ones

Water jacket core sections available, so two separate components. This can either take place in that a produced water jacket core (blank) is divided into at least two parts, for example cut open. However, it would also be conceivable in particular that at least two separate water jacket core sections (blanks), that is to say at least two components, are initially produced. Because there are initially at least two separate water jacket core sections, on

a structure can be introduced in a comparatively simple manner, in particular at the later joining surfaces of the water jacket core sections. The Water jacket core sections are joined, so as a total of a particularly one-piece (monolithic)

Manufacture water jacket core.

Overall, according to the invention, comparatively

inexpensive at least one cooling channel in one

Water jacket core are introduced. When operating the water jacket core in a die casting device,

Cooling fluid are passed through the cooling channel in order to reduce the thermally induced stress on the water jacket core and the service life, in particular the

affordable number of casting cycles to extend the water jacket core.

An advantageous development of the invention provides that the water jacket core sections in step b.

arranged one above the other and then joined.

Consequently, it is conceivable that the water jacket core sections are arranged in the form of at least two layers on top of one another in order to form the one-piece water jacket core as a whole after joining. The respective water jacket core section can be horizontal

Have extension along a main extension plane. At right angles to this, the respective water jacket core section can have a vertical extension with a height h.

Another advantageous embodiment of the invention provides that the water jacket core sections each have one

Have top and bottom, wherein in step a. in at least one top of one A recess is introduced into the water jacket core section, wherein in step a. in at least one underside of another water jacket core section one to it

complementary recess is introduced, and wherein the water jacket core sections are joined so that the

Recesses after joining the two

Water jacket core sections a horizontal

Form cooling channel section. The upper side of the one water jacket core section consequently forms a joining surface which can be joined to the lower side of the other water jacket core section, which also forms a joining surface. Before joining, recesses can be made in the bottom or top in a particularly simple manner. The water jacket core sections can then be joined so that the recesses are on top of each other

System get to such a cooling channel section

to train.

The top or bottom can thereby

in any case be designed in sections in an arc-shaped manner, so that the recess can also extend in an arc-shaped manner in sections in any case. After the two water jacket core sections have been joined, a

in any case more arcuately extending in sections

Cooling channel section provided. This arcuate cooling channel section can in particular lie in the area where a cylinder of the cylinder block is cast. It is also advantageous if the horizontal

Cooling channel section after joining an oval or

Has elongated cross-section. In the case of a symmetrical oval design, the main axis of symmetry can be perpendicular to the main extension of the

Extend water jacket core. In the case of an elongated hole-like cross section, this can accordingly be designed in the form of a standing elongated hole. This can

in particular, a sufficient flow area

be provided so that despite the cramped

Spatial conditions - because the water jacket core is a

has comparatively low wall thickness - one

sufficient cooling of the water jacket core can be provided.

It is particularly preferred if in step a. a material recess, in particular a bevel, is provided on the edges of the recesses. Such a bevel can be used in

particularly simple way after introducing the

Recesses are provided.

In this context it is conceivable that step b. comprises a diffusion welding process. In such a diffusion welding process, the individual

Water jacket core sections into a one-piece

Water jacket core are connected. In the course of the

Diffusion welding will be the individual

Water jacket core sections connected to one another at the joining surfaces. It is conceivable here that material also flows in the direction of the cooling channel sections. By providence a chamfer on the edges of the recesses, the material can fill the chamfers, so that even after

Diffusion welding process the cooling channel sections are not clogged, but rather still one

have a sufficient cross-section. The bevels can consequently be viewed as a type of weld hollow seam or weld hollow fillet.

However, it is also conceivable that step b. one

Includes vacuum brazing process. One of those too

The joining process has proven to be suitable.

However, diffusion welding suggests better "durability" of the joint.

The water jacket core sections are advantageously connected by means of dowel pins before the joining process.

The individual water jacket core sections can so

be connected precisely so that after joining

in particular individual recesses in the upper

or undersides of the water jacket core sections come to lie one on top of the other, so one

Form cooling channel section. The dowel pins can be set in the water jacket core section blanks in areas outside the final water jacket core geometry, so that the dowel pins are no longer present in the water jacket core after finishing.

Alternatively, in the water jacket core section blanks (possibly also outside the final water jacket core geometry) a suitable fitting geometry, for example in the form of tenons and corresponding bores, are processed. This has the advantage that no separate dowel pins for joining the

Water jacket core section blanks are required and consequently can not be forgotten in the manufacturing process to provide the dowel pins, what the

Reduced risk of errors in the manufacturing process.

Preferably 3 to 5 water jacket core sections are joined to one another to produce the water jacket core.

It would also be conceivable, more than three to five

Provide water jacket core sections. Three to five

However, water jacket core sections allow one

Production of a water jacket core with at least one cooling channel with manageable additional costs. It is conceivable that the later lower water jacket core section only has a recess on its upper side, while the later upper water jacket core section has a recess only on its underside, while the

have intervening water jacket core sections on their top and bottom recesses. The

After the recesses have been made, water jacket core sections can then be arranged one above the other in order to form at least one cooling channel.

A particularly preferred development of the invention results from the fact that in step a. perpendicular to a main extension of the water jacket core sections, at least one vertical cooling channel section in at least one

Introduced water jacket core section, in particular

is drilled in. This vertical cooling channel section can in particular lead to a cooling fluid connection, in particular a water connection, so that cooling fluid via a vertical cooling channel section to the horizontal

Cooling channel sections can be guided and can be discharged via a further vertical cooling channel section from which at least one cooling channel.

A particularly preferred development of the invention provides that the method comprises the further step:

c. Hardening of the joined water jacket core.

Hardening can be, for example

Heat treatment process with at least one on it

have subsequent starting process. It is particularly preferred if the method comprises the further step:

d. Editing the water jacket core to match the

Giving the water jacket core its final shape.

It is conceivable that the water jacket core or the individual water jacket core sections are initially in a raw form. Then the individual

Cooling channel sections are introduced. The joining process can then be carried out in order to then

To obtain water jacket core blank, which can then be hardened. It can be in the raw form

in particular a hardening delay can be reduced, so that the risk is reduced that there is a hardening

Hardship delay comes. The method advantageously includes the further

Step:

e. Stress relief annealing of the water jacket core.

As a result, the internal stresses of the

Water jacket core can be reduced. The water jacket core can then be coated, for example nitrided and / or PVD-coated. The application of

Multi-layer layers are conceivable.

The object set out at the beginning is also achieved by a water jacket core produced by means of a

method according to the invention. One of those

The water jacket core has at least one cooling channel. The water jacket core can be produced at manageable costs compared to cooling-free water jacket cores. In this way, a water jacket core with cooling can be manufactured more economically, in particular, in comparison to one manufactured by means of a 3D metal printing process

Water jacket core.

Finally, the object set out at the beginning is also achieved by a method for producing a cylinder block of an engine housing by means of die casting, with a

A water jacket core according to the invention is used in a die casting mold, and wherein a cooling fluid is passed at least temporarily through the at least one cooling channel of the water jacket core during the pressure casting process.

The cylinder block can be designed in the so-called "open deck" configuration. The inventive The water jacket core can consequently be put into the die casting mold

can be used. In the case of series blocks, the

Water jacket core usually as part of the

Main use of the movable mold half and, in the case of V-blocks, as a partial insert in the slide attachment of the inclined slide. After a cylinder block has been manufactured, it can be removed from the water jacket core. The cylinder block can have at least one, but in particular several, for example three cylinders,

exhibit. Because cooling fluid, in particular heat transfer oil or (heated) cooling water, is passed through the at least one cooling channel of the water jacket core at least temporarily during the printing process, thermal stresses in the water jacket core can be reduced, which advantageously leads to longer

Lifetime leads. Heat transfer oil or heated cooling water by means of pressurized water devices are preferably used. Due to the small distance to the contour surface, a sufficient cooling effect can nevertheless be achieved. In addition, the water jacket core can be prevented from becoming unnecessarily cold. This also reduces tension during the next filling process.

Clocked cooling is also conceivable, for example with a jet cooling process, or without "emptying" the

Cooling channels after the active cooling phase.

Further details and advantageous embodiments of the invention can be found in the following description, on the basis of which the illustrated in the figures From embodiment of the invention is described and explained in more detail.

Show it:

Figure 1 schematic top view of a

Cylinder block of an engine case;

Figure 2 is a schematic perspective illustration

a water jacket core according to one

Embodiment;

FIG. 3 shows a further perspective illustration of

Embodiment according to Figure 2;

Figure 4 is yet another illustration of the

Embodiment according to Figure 2; and

Figure 5 is a schematic perspective illustration

a water jacket core section prior to joining.

FIG. 1 shows a total of a cylinder block 10, which in this case has three cylinders 12, 14, 16. Everyone

Cylinder extends along one of them

associated cylinder axis 18, 20, 22. Each cylinder 12, 14, 16 is delimited by a respective cylinder wall 24, 26, 28. Each of the cylinder walls 24, 26, 28 has a cylindrical running surface 30, 32, 34 pointing radially inward. Furthermore, the cylinder walls 24, 26, 28 each have a radially outwardly facing wall surface 36, 38, 40. The aforementioned wall surfaces 36, 38, 40 form a radial inner boundary for a cooling channel 42 (also called water jacket 42). The cooling channel 42 is also delimited by an inner side 44 of an outer wall 46 of the cylinder block 10. The cylinder block 10 is therefore as

so-called "open-deck" type. The cylinder block 10 is produced in a die-casting process. To make the water jacket 42, a water jacket core is inserted into the

Die casting mold used. In the case of series blocks, this is usually inserted as a partial insert in the main insert of the movable mold half, and in the case of V-blocks as a partial insert in the slide attachment of the inclined slide. Using the

A cavity for forming the water jacket in the cylinder block 10 can consequently be produced in the water jacket core.

During operation of the engine, the water jacket 42 is with

Cooling fluid, in particular flushed with water, in order to provide cooling of the cylinder block 10 around the cylinders 12, 14, 16.

Figure 2 shows a total of a water jacket core 48 according to one embodiment. The water jacket core 48 can be made from hot work tool steel.

The water jacket core 48 has three almost cylindrical sections 50, 52, 54 which merge into one another at transitions 56, 58, 60, 62 which can be seen in FIG. Almost cylindrical means that the sections 50, 52, 54 have a draft angle of, for example, 1-2 ° per side

may have to dated a casting after the casting process To be able to demold the water jacket core again. The cylinders 50, 52, 54 are hollow cylinders with a

Housing wall 51, 53, 55 formed, the transitions 56, 58 and 60, 62 with one another via connecting sections 57, 59 in the upper region of the water jacket core 48

are connected (see FIG. 4). The water jacket core 48 is integrally formed as a whole and has a

Core section 49, which is designed to enable a fluid supply or discharge. Each cylinder 50, 52, 54 is provided with a cooling channel 64, 66, 68. Each cooling channel 64, 66, 68 has horizontal sections 70, 72 and 74 which are parallel to the

Main plane of extent of the water jacket core 48 run. The individual horizontal cooling channel sections 70, 72, 74 are above vertical cooling channel sections 76, 78, 80

connected, the vertical cooling channel sections 76, 78, 80 consequently perpendicular to the main extension plane of the

Water jacket core 48 run.

The underside 82 of the shown in FIG

Water jacket cores 48 extend vertically

Cooling channel sections 84, 86, through which cooling fluid can be introduced or executed into the cooling channel 64. Likewise, further cooling channel sections 88, 90, 92, 94 extend through the underside 82 in order to supply the cooling channels 66, 68 with cooling fluid. The middle cooling channel 66 also has a horizontal one

Connection cooling channel section 96 which extends through the connection section 59. The overall water jacket core 48 is manufactured by the following process:

The one-piece water jacket core 48 comprises a total of five water jacket core sections 102, 104, 106, 108, 110 (see FIG. 2). The middle section 106 is shown in Figure 5 as an individual part. The individual sections 102 to 110 are initially available as individual parts. The sections 102 to 110 can either be produced as individual components. However, it would also be conceivable that first a component is produced that includes the sections 102 to 110 and that the component is then separated from one another along parting planes in order to obtain the sections 102 to 110 as individual parts. Preferably, the sections 102 to 110 are first manufactured separately as individual parts. Smaller machines and comparatively short tools with comparatively

fast processing parameters can be used in an advantageous manner.

As shown in Figure 5, the

Water jacket core section 106 nearly cylindrical walls 112, 114, 116, an outer side 118, an inner side 120, an underside 122 and an upper side 124. Almost

Cylindrical means that the walls 112, 114, 116 have a draft angle of, for example, 1-2 ° per side

can have in order to be able to demold a casting from the water jacket core after the casting process. In

vertical / perpendicular direction 125 points

Water jacket core section 106 has a height h. The almost cylindrical walls 112, 114, 116 are open at the lateral transitions from one wall to the other wall. This also applies to sections 104 and 108-110. Section 102 points in contrast

continuous, almost or in particular also completely, cylindrical walls (see. Fig. 2-4). Furthermore, the section 106 comprises part of the core section 49. First, cutouts 126, 128, 130 are made on the underside 122. This can be done for example by a

Milling process. The recesses 126 to 130 consequently form horizontal recesses. Furthermore, vertical cooling channel sections 132, 134 are introduced, for example drilled. In the same way, recesses are made on the upper side 124.

In a similar way, recesses and vertical cooling duct sections are provided in the sections 104, 108 on the respective upper and lower sides. Furthermore, recesses are made on the underside of section 110 and on the top of section 102.

The sections 102 to 110 are then arranged one on top of the other, these being arranged for a precisely fitting arrangement by means of dowel pins or machined fitting geometries (both not shown). The sections 102 to 110 are then permanently connected to one another by a diffusion welding process in order to create a total

to obtain monolithic water jacket core 48. The

respective upper and lower sides consequently

There are joining surfaces. Here, cutouts come from one another opposite tops and bottoms of the

Sections 102 to 110 one above the other to rest in order to form horizontal cooling channel sections. A

horizontal cooling channel section can in particular have an oval or upright slot-like cross section. In the case of an oval configuration, it can be an elliptical cross-section, with the major axis of the ellipse in the vertical direction

extends. Similarly in case one extends

The main axis in the vertical direction. As a result, the limited space available can be optimally used in order to still be able to provide a sufficient cooling fluid flow rate. The vertical cooling channel sections 132, 134 are introduced at the transitions 136, 138 at which, as can be clearly seen in FIG. 5, the wall thickness b2 is greater than the wall thickness b1 in other sections (cf. complementary to FIG. 1). During the diffusion welding process, material can flow in the direction of the recesses 126 to 130. In order to avoid an undesirable narrowing of the resulting cooling channel sections, a bevel can be introduced, for example ground in or in particular milled, on the edges 140 of the cutouts.

Flowing material on the joining surfaces can therefore fill the chamfers. Nevertheless, a reduction in the cross section of the cooling channel section can advantageously be avoided. After the diffusion welding process, the water jacket core 48 can be hardened, for example by heat treatment with subsequent tempering processes. The water jacket core 48 can then finish to the final geometry

to be edited. It is particularly conceivable that the final geometry is only produced from a blank after hardening. This can minimize hardening distortion. The internal stress of the water jacket core 48 can then be reduced by stress relief annealing.

The water jacket core 48 produced in this way (cf. FIGS. 2-4) comprises three cooling channels 64, 66, 68, each with horizontal cooling channel sections in four parallel to one another

Main planes of extent as well as each with vertical

Cooling duct sections that make up the horizontal

Connect cooling duct sections together.

The water jacket core 48 can be held in a casting mold in the area of the segment 102 (cf. FIG. 2), in particular in a recess in the movable mold insert, and can be held by so-called pinoies (which can fill the cylinder space and by a step that each three smaller and larger diameter of segment 102

can be filled in) be kept in the form.

Overall, the method allows cooling channels 64, 66, 68 in a water jacket core in a cost-effective manner

48 are introduced. If cylinder blocks 10 are then cast, cooling fluid, in particular heat transfer oil or (heated), can be used during the die casting process. Cooling water, through which cooling lines 64, 66, 68 are passed in order to reduce thermal stresses and thus to keep the service life of the water jacket core 48 advantageously long.

Claims

A method for making a water jacket core (48), the method comprising the steps of: a. Introduction of structures (126, 128, 130, 132,

134) for forming cooling channel sections (70, 72, 74, 76, 78, 80) in at least two separate water jacket core sections (102, 104, 106, 108,

110); and b. Joining the water jacket core sections (102, 104,

106, 108, 110) to obtain a water jacket core (48) with at least one cooling channel (64, 66, 68).

2. The method of claim 1, wherein the

Water jacket core sections (102, 104, 106, 108, 110) in

Step b. arranged one above the other and then joined.

3. The method of claim 1 or 2, wherein the

Water jacket core sections (102, 104, 106, 108, 110) each have a top side and a bottom side, wherein in step a. a recess is made in at least one upper side of a water jacket core section (102, 104, 106, 108, 110), wherein in step a. in at least one bottom of another

Water jacket core section (102, 104, 106, 108, 110) a complementary recess is introduced, and the water jacket core sections (102, 104, 106,

108, 110) are joined in such a way that the recesses (126, 128, 130) after joining the two

Water jacket core sections (102, 104, 106, 108, 110) form a horizontal cooling channel section (70, 72, 74).

4. The method of claim 3, wherein the horizontal

Cooling channel section (70, 72, 74) has an oval or slot-like cross section after joining.

5. The method according to claim 3 or 4, wherein in step a. a material recess, in particular a bevel, is provided on the edges (140) of the recesses (126, 128, 130).

6. The method according to any one of the preceding claims, wherein step b. comprises a diffusion welding process.

7. The method according to any one of claims 1 to 5, wherein

Step b. comprises a vacuum brazing process.

8. The method according to any one of the preceding claims, wherein the water jacket core sections (102, 104, 106, 108, 110) before the joining process by means of dowel pins or

Fitting geometries are connected.

9. The method according to any one of the preceding claims, wherein for the production of the water jacket core (48) 3 to 5

Water jacket core sections (102, 104, 106, 108, 110) are joined together.

10. The method according to any one of the preceding claims, wherein in step a. perpendicular to a main extension of the water jacket core sections (102, 104, 106, 108, 110) at least one vertical cooling duct section (76, 78, 80) is introduced, in particular drilled, into at least one water jacket core section (102, 104, 106, 108, 110).

11. The method according to any one of the preceding claims, comprising the further step: c. Hardening the joined water jacket core (48).

12. The method of claim 11, comprising the further step of: d. Machining the water jacket core (48) to the

To give water jacket core (48) its final shape.

13. The method according to claim 12, comprising the further step: e. Stress relief annealing of the water jacket core (48), and then in particular also coating, for example nitriding and / or PVD coating, of the water jacket core (48).

14. Water jacket core (48) made by means of a

Method according to one of the preceding claims.

15. A method for producing a cylinder block (10) of an engine housing by means of die casting, a water jacket core (48) according to claim 14 being placed in a die casting mold is used, and wherein a cooling fluid is passed at least temporarily through the at least one cooling channel (64, 66, 68) of the water jacket core (48) during the die-casting process.