WO2018148774A1

WO2018148774A1 - Internal combustion engine comprising a cylinder crankcase

Info

Publication number: WO2018148774A1
Application number: PCT/AT2018/060043
Authority: WO
Inventors: Stefan Feichtinger; Stefan STOCKER-REICHER; Günter Häusl
Original assignee: Avl List Gmbh
Priority date: 2017-02-14
Filing date: 2018-02-14
Publication date: 2018-08-23
Also published as: AT519757B1; AT519757A4

Abstract

The invention relates to an internal combustion engine comprising a cylinder crankcase (1) having at least two cylinders (2) arranged next to one another, each having a wet cylinder sleeve (3) accommodated in a support structure (4), wherein a coolant jacket (5) having a closed upper deck (7) forming a cylinder head sealing surface (6) is disposed between the support structure (4) and the cylinder sleeve (3), and at least one first screw receptacle (9) for a cylinder head screw (28) is disposed between two cylinders (2) in the region of an engine transverse plane (8). In order to enable optimum cooling without sealing problems, the invention provides for the first screw receptacle (9) to be at a distance from the upper deck (7), wherein the support structure (4), the upper deck (7) and an intermediate deck (19) connecting the first screw receptacle (9) and the support structure (4) span an intermediate space (27) between two respective cylinders (2), which is separated from the coolant jacket (5) and is penetrated by the cylinder head screws (28).

Description

Internal combustion engine with a cylinder crankcase

The invention relates to an internal combustion engine having a cylinder crankcase with at least two juxtaposed cylinders each having a wet cylinder liner, which is received by a support structure, wherein between the support structure and the cylinder liner, a coolant jacket is arranged, with a cylinder head sealing surface forming a closed upper deck, wherein in the area a motor transverse plane between two cylinders at least a first screw receptacle for a cylinder head screw is arranged.

In cast cylinder blocks with wet cylinder liners, the cylinder liners on your outer jacket are surrounded by coolant. A cast cylinder crankcase with wet cylinder liners is known for example from DE 10 2012 111 521 AI. In this case, usually the cylinder liners receiving support structures of the cylinder crankcase of two adjacent cylinders in the engine transverse plane are connected to each other. This results in mechanical and thermal disadvantages.

From JP 2011-163215 A a cast cylinder crankcase is known, which has relatively deep disposed in the cylinder crankcase first screw receptacles for the cylinder head bolts. The first screw receptacles are positioned in a central region of the cylinder and spaced from the upper upper deck. The cylinder head bolts are guided through the cooling water jacket or through a sleeve inserted into the cooling water jacket. This can lead to tightness problems.

The object of the invention is to avoid the disadvantages mentioned and to allow optimum cooling without leakage problems, with the mechanical and thermal stress of the cylinder crankcase to be reduced.

According to the invention, this object is achieved in an internal combustion engine of the type mentioned above in that the first screw receptacle is spaced from the upper deck, wherein the support structure, the upper deck and an intermediate deck connecting the first screw receptacles and the support structure span a space between each two cylinders separated from the coolant space, which is penetrated by the cylinder head bolts. The fact that the first screw receptacles are deeply embedded in the cylinder crankcase, a particularly favorable power flow is achieved. This reduces deformation of the cylinder liner. The distance of the first screw receptacle from the upper deck is preferably at least about half the cylinder diameter of the cylinder.

The invention results in an advantageous distribution of force in a one-piece, for example cast, cylinder housing.

Advantageously, in the region of at least one engine transverse plane between two cylinders, a main bearing wall formed integrally with the cylinder housing is arranged

The gap is free of coolant, and preferably also free of lubricant, thus occur in the screw holes no leakage problems in connection with a liquid medium.

In order to minimize the thermal and mechanical stresses in the cylinder crankcase, it is advantageous if the support structures of two adjacent cylinders in the intersection region of the engine transverse plane with one of the cylinder axes-containing engine longitudinal plane are exempted from each other. In a particularly favorable embodiment of the invention, the minimum distance between two adjacent support structures in the region of the coolant jacket corresponds to at least half the cylinder head screw diameter, preferably at least the cylinder head screw diameter. This allows a substantial thermal and mechanical decoupling of two adjacent cylinders from each other.

For further mechanical decoupling, it may further be provided that at least one first screw receptacle is arranged in a middle region-in particular in a middle third-of the cylinder, wherein the first screw receptacle preferably adjoins laterally on two adjacent support structures. This allows a substantial decoupling of the cylinder head bolts from the support structure.

Preferably, the support structure is formed in the region of the coolant jacket substantially hollow cylindrical, with a particularly good cooling of thermally highly stressed areas can be achieved when the coolant jacket between a cylindrical inner wall of the support structure and a cylindrical outer wall of the cylinder liner, preferably in the upper third of the cylinder formed is.

Preferably, the intermediate deck is connected to a main bearing wall. This causes an advantageous introduction of force from the first screw receptacle in the main bearing wall and a stable mechanical support of the cylinder crankcase.

To achieve an optimal power flow within the cylinder crankcase, it is advantageous if at least one second screw receptacle, preferably all second screw receptacles, is farther away from the crankshaft axis than the maximum counterweight radius of the crankshaft. Conveniently, it is provided in one embodiment of the invention that the second screw receptacle is arranged in the region between two adjacent cylinders.

In a further embodiment of the invention, the support structure forms a substantially normal to the cylinder axis arranged lower deck, which has a support bore for receiving the cylinder liner, the lower deck, the intermediate deck and the cylinder liner a Übertrittraum, especially for blow-by gases span. At least a second screw receptacle is arranged adjacent to the transfer room.

It is particularly advantageous if, during operation of the internal combustion engine, the support structure is subjected to tensile forces in a region formed between the cylinder head sealing surface and the screw receptacle by compressive forces and the remaining region of the support structure and the main bearing walls. This allows a substantial mechanical and thermal decoupling on the one hand the cylinder from each other and on the other hand from the cylinder head bolts. Likewise, a deformation of the cylinder liner is reduced.

The invention is explained in more detail below with reference to a non-limiting example shown in the figures. Show:

1 shows a cylinder crankcase of an internal combustion engine according to the invention in a section along the line I-I in Fig. 2.

2 shows the cylinder crankcase in an oblique view in a section along the line II-II in Fig. 1.

3 shows the cylinder crankcase in a section along the line III -

III in Fig. 1;

4 shows the cylinder crankcase in a section along the line IV -

IV in Fig. 3;

5 shows the cylinder crankcase in a section along the line V - V in Fig. 1. and 6 shows the cylinder crankcase in a section along the line VI - VI in Fig. 2nd

The cylinder crankcase 1 of an internal combustion engine is designed for a plurality of juxtaposed cylinders 2 with wet cylinder liner 3, which are each received by a support structure 4 of the cylinder crankcase 1. The internal combustion engine shown in FIGS. 1 to 6 is designed as a V-engine with two cylinder rows. The invention is also applicable to other engine types, such as in-line engines.

The cylinder crankcase 1 is made in one piece and takes over the function of supporting the cylinder liners 3, as well as in Figs. 5 and 6 indicated crankshaft 31. For storage of the crankshaft 31, the cylinder crankcase 1 integrated main bearing walls 18 in the range of engine transverse planes 8. The main bearing walls 18 can be formed exactly in the respective engine transverse plane 8 or slightly offset from this. Furthermore, a housing skirting of the cylinder crankcase 1, for example, in one casting operation or an additive process, for example a 3D printing operation, for example, clamps on a crank chamber 16 for accommodating the crankshaft 31.

In one piece with the cylinder crankcase 1 are the cylinder housing 33, the crankcase 34 together with the crankcase skirt 35 and main bearing walls 18 of the internal combustion engine.

As is apparent from FIGS. 1 and 2, a coolant jacket 5 is arranged between the support structure 4 and the cylinder liner 3. On both sides of the coolant jacket 5, the cylinder liner 3 is located on sealing surfaces 4a, 4b of the support structure 4 close to this, with reference numeral 11 seals are designated. The support structures 4 are formed in the region of the coolant jacket 5 is substantially hollow cylindrical. The coolant jacket 5 fed by the coolant collector 20 via the coolant passageway 21 extends in the radial direction between a cylindrical inner wall 13 of the support structure 4 and a cylindrical outer wall 14 of the cylinder liner 3 and is arranged in the upper third 15 of the cylinder 2. As the upper third 15 is here that third of the cylinder 2 to understand, which faces the cylinder head sealing surface 6. The coolant passage 21 opens in an arc in the coolant jacket 5, whereby the amount of coolant is divided over the cylindrical coolant jacket 5 in a predefined manner. This allows a uniform cooling of the cylinder 2. At the top of the cylinder crankcase 1 facing the cylinder head not shown, this has a closed upper deck 7 forming a cylinder head sealing surface 6. In the region of a motor transverse plane 8, two first screw receptacles 9 for cylinder head screws 28 are arranged at a distance from the upper deck 7 between two cylinders 2. In the exemplary embodiment, the distance b of the first screw receptacle 9 from the upper deck 7 corresponds approximately to half the cylinder diameter D of the cylinder 2. The screw receptacles 9 can be formed exactly in the respective engine transverse plane 8 or slightly offset from this.

The support structures 4 of two adjacent cylinders 2 are separated from one another in the sectional area S of the engine transverse plane 8 with an engine longitudinal plane 10 containing the cylinder axes 2a, wherein the minimum distance a of two adjacent support structures 4 in the region of the coolant jacket 5 in the exemplary embodiment corresponds approximately to the cylinder head screw diameter d.

Each first screw receptacle 9 adjoins laterally on two adjacent support structures 4. The support structures 4 have areas adjoining the coolant jacket 5 in the direction of the crank space 16 - in particular in the area of the first Screw holders 9, conically shaped transition areas 17. The conically shaped transition regions 17 taper in the direction of the upper deck 7. In the region of the base 17 a of the conically shaped transitional regions 17, adjacent support structures 4 are connected to one another via an intermediate deck 19. At the transition areas 17 close to the crank chamber 16 toward main bearing walls 18. This arrangement forms an advantageous force guide with compressive forces C and tensile forces T in the cylinder housing 1, as indicated in Fig. 2. Above the screw receptacle 9 - in the illustrated embodiment in the upper third 15 of the cylinder 2 - act during operation of the internal combustion engine compressive forces C on the support structure 4 of the cylinder crankcase 1 a. The remaining region of the support structure 4, in the illustrated embodiment that is in the middle third of the cylinder 2 and 2, and the main bearing walls 18 of the cylinder crankcase 1, however, are subjected to tensile forces T.

Characterized in that the support structures 4 are spaced from each other in the engine longitudinal plane 10 and the first screw receptacles 9 from the upper deck 7, a substantial mechanical and thermal decoupling on the one hand the cylinder 2 from each other and on the other hand achieved by the cylinder head bolts. Likewise, a deformation of the cylinder liner 3 is reduced. It is shown in FIGS. 3 and 4 that the support structure 4 forms a lower deck 22 arranged substantially normal to the cylinder axis 2 a. The lower deck 22 has per cylinder a support bore 32 for receiving the respective cylinder liner 3, wherein the lower deck 22, the intermediate deck 19 and the cylinder liner 3 span a Übertrittraum 23, which faces the cylinder 2 in its lower region, for example in the crank chamber 16 lower half, surrounds. The transfer chamber 23 is flow-connected via one or more transfer openings 24 with the crank chamber 16. About the transfer openings 24 reach blow-by gases according to the arrows P from the crank chamber 16 in the Übertritträume 23, flow around the cylinder liners 3 and enter the camshaft space 25 of the cylinder crankcase 1. The outlet 26 for the blow-by gases can - like provided in the embodiment - be arranged on the top or on a longitudinal or front side of the cylinder crankcase 1.

As can be seen from FIGS. 1, 2, 5 and 6, the support structure 4, the upper deck 7 and the intermediate deck 19 clamp a gap 27, which is separate from the coolant jacket 5, between two cylinders 2 in each case. The gap 27 is penetrated by the cylinder head bolts 28. The gap 27 has no connection to the coolant or lubricant, whereby sealing problems associated with the cylinder head bolt holes 29 in the cylinder head sealing surface 6 are avoided.

The main bearing wall 18 has in the exemplary embodiment two second screw receptacles 29 for receiving main bearing screws 30. The second screw receptacles 29 are arranged deep in the cylinder crankcase 1 in the region between two adjacent cylinders 2 of a row of cylinders and extend into the Übertritträume 23 inside. The minimum distance c between the thread of each second screw receptacle and the axis of rotation 31a of the crankshaft 31 is greater than the maximum circumferential radius r indicated in FIG. 6 - counterweights of the crankshaft 31 (not shown).

Claims

PATENT APPLICATIONS

1. Internal combustion engine with a cylinder crankcase (1) with at least two juxtaposed cylinders (2), each with a wet cylinder liner (3) which is received by a support structure (4), wherein between the support structure (4) and the cylinder liner (3 ) a coolant jacket (5) is arranged, with a cylinder head sealing surface (6) forming closed upper deck (7), wherein in the region of a motor transverse plane (8) between two cylinders (2) at least a first screw receptacle (9) for a cylinder head screw (28) is arranged, characterized in that the at least one first screw receptacle (9) from the upper deck (7) is spaced, wherein the support structure (4), the upper deck (7) and a first screw receptacle (9) and the support structure (4) connecting Tween deck (19) spanned by the coolant jacket (5) gap (27) between each two cylinders (2) span, which of the cylinder head bolts (28) passes through is.

2. Internal combustion engine according to claim 1, characterized in that the distance (b) of the first screw receptacle (9) from the upper deck (7) is at least about half the cylinder diameter (D) of the cylinder (2).

3. Internal combustion engine according to claim 1 or 2, characterized in that the support structures (4) of two adjacent cylinders (2) in the intersection region (S) of the engine transverse plane (8) with a cylinder axes (2a) containing engine longitudinal plane (10) are spaced from each other.

4. Internal combustion engine according to claim 3, characterized in that the minimum distance (a) of two adjacent support structures (4) in the region of the coolant jacket (5) at least half the cylinder head screw diameter (d), particularly preferably at least the cylinder head screw diameter (d) equivalent.

5. Internal combustion engine according to one of claims 1 to 4, characterized in that at least one first screw receptacle (9) in a central region - in particular a middle third (12) - of the cylinder (2) is arranged, wherein preferably the first screw receptacle (9 ) laterally adjacent to support structures (4) of two adjacent cylinders (2).

6. Internal combustion engine according to one of claims 1 to 5, characterized in that the support structure (4) in the region of the coolant jacket (5) is formed substantially hollow cylindrical.

7. Internal combustion engine according to one of claims 1 to 6, characterized in that the intermediate deck (19) with a at least one second screw receptacle (2) having main bearing wall (18) is connected.

8. Internal combustion engine according to claim 7, with a in the cylinder crankcase (1) arranged crankshaft (31), which has at least one crank arm with a counterweight to compensate for rotating and / or oscillating masses, characterized in that at least one second screw receptacle (29), Preferably, all the second screw receptacles (29) from the axis of rotation (31a) of the crankshaft (31) is / are farther than the maximum counterweight radius (r) of the crankshaft (31).

9. Internal combustion engine according to claim 7 or 8, characterized in that the second screw receptacle (29) in the region between two adjacent cylinders (2), is arranged.

10. Internal combustion engine according to one of claims 1 to 9, characterized in that the support structure (4) has a substantially normal to the cylinder axis (2a) arranged lower deck (22) having a support bore (32) for receiving the cylinder liner (3) , wherein the lower deck (22), the intermediate deck (19) and the cylinder liner (3) span a transfer space (23), in particular for blow-by gases.

11. Internal combustion engine according to claim 10, characterized in that at least one second screw receptacle (29) adjacent to the transfer space (23).

12. Internal combustion engine according to one of claims 1 to 11, characterized in that the coolant jacket (5) between a cylindrical inner wall (13) of the support structure (4) and a cylindrical outer wall (14) of the cylinder liner (3), preferably in the upper third ( 15) of the cylinder (2) is formed.

13. Internal combustion engine according to one of claims 1 to 12, characterized in that in the region of at least one engine transverse plane (8) between two cylinders (2) is integrally formed with the cylinder housing (1) formed main bearing wall (18).

14. Internal combustion engine according to one of claims 1 to 13, characterized in that in the installed state during operation of the internal combustion engine, the support structure (4) in a between the cylinder head sealing surface (6) and the screw receptacle (9) formed area By compressive forces (C) and the remaining region of the support structure (4) and the main bearing walls (18) by tensile forces (T) are applied.