KR20180065940A - Cylinder head - Google Patents

Abstract

The present invention relates to a cylinder head (1) of a liquid cooled internal combustion engine, wherein the cylinder head (1) has a cooling chamber device (5) adjacent to a fire deck (3) The upper cooling compartment 5b is divided into a lower cooling compartment 5a and an upper cooling compartment 5b on the side of the fire deck by an intermediate deck 4 disposed substantially parallel to the fire deck 3, The upper cooling compartment 5b and the lower cooling compartment 5a are arranged on one side of the intermediate deck 4 facing toward the side away from the fire deck 3 in the direction of the cylinder axis 2, Flow through openings 6 and at least one overflow opening 6, which is preferably arranged adjacent to the receiving sleeve 7. The overflow opening 6, An object of the present invention is also to provide a cylinder head (1) in which a region subjected to a high thermal load is cooled optimally. This object is achieved in accordance with the invention in that the overflow opening 6 comprises at least one ring segment portion 6a which extends annularly around the cylinder axis 2 and a radially extending cylinder axis 2 from the ring segment portion, And a protruding portion 6b that faces away from the protruding portion 6b.

Description

Cylinder head {CYLINDER HEAD}

The present invention relates to a cylinder head of a liquid cooled internal combustion engine, wherein the cylinder head has a cooling chamber arrangement adjacent to a fire deck, the cooling chamber arrangement comprising a middle chamber The upper cooling compartment is disposed on one side of the intermediate deck facing the side away from the fire deck in the direction of the cylinder axis and the lower cooling compartment is located on the lower cooling compartment and the upper cooling compartment, The cooling compartment is flow connected through at least one overflow opening extending around the cylinder axis, and the overflow opening is preferably disposed adjacent the receiving sleeve. The present invention also relates to an internal combustion engine having such a cylinder head.

The applicant's AT 005 939 U1 discloses a cylinder head in which coolant flows into the lower cooling compartment through an annular overflow opening between the intermediate deck and the receiving sleeve for the central part from the upper cooling compartment. The coolant flows into the cooling chamber of the crankcase through the overflow opening from the lower cooling compartment. In this case, the flow occurs evenly throughout the valve bridge, but there is no particular directional effect, which may result in a disadvantage in the cooling effect in some applications. A similar solution is given in AT 503 182 A2.

In AT 510 857 B1, an inlet channel is provided between the upper cooling compartment and the lower cooling compartment, which has a ring-shaped or ring-segmented inlet opening in the central region. Thus, in order to improve heat dissipation in the region of the outlet valve seat and the valve bridge, a tailoring to the local thermal requirements of the next valve bridge passage is sought.

The known configuration has the disadvantage that it is only possible to insufficiently fit the cooling to the area subjected to the high thermal load of the cylinder head, which may be necessary in some applications. The flow variance for the other radial cooling channel can only be set through the magnitude of the overflow opening for the cylinder housing. As a result, the radial cooling channels at the inlet and outlet sides are cooled, but are disadvantageous for the temperature distribution at the inlet fire deck. As a result, the temperature distribution in the fire deck becomes uneven, causing material stress in the cylinder head. At the same time, the cross-sectional area of the overflow opening can only be extended to a limited extent due to the strength of the cylinder head, so that the coolant may be insufficiently pounded or the pressure condition may be disadvantageous. Also, since the cooling water flows vertically through the overflow opening to the fire deck and then directly into the radial cooling channel, the intended flow around the receiving sleeve in the lower cooling compartment through the circular ring overflow opening is not possible.

It is an object of the present invention to avoid these disadvantages and to optimally cool the areas subject to high thermal stress of the fire deck and the receiving sleeve.

This object is achieved with the firstly mentioned cylinder head according to the invention in which the overflow opening comprises at least one ring segment portion extending annularly around the cylinder axis and a ring segment portion extending radially from the cylinder axis, And has a protruding portion facing toward the side. In other words, therefore, the overflow opening has a first portion extending in the form of a circular segment around the cylinder axis, from which the second portion begins, and the second portion extends radially from the cylinder axis It is designed as a direction projection part.

In the present invention, the circular ring segment is a circular ring portion extending in an angular range of less than 360 degrees.

For purposes of this disclosure, it is to be understood that the cylinder axis is the longitudinal center axis of the cylinder extending essentially perpendicular to the fire deck or cylinder head sealing surface.

As a result of the limited extension of the ring segment portion and the projecting portion, the flow velocity at the transition between the cooling compartments increases and thus the flow is concentrated. In particular, due to the protruding portion, the cooling is increased in the region subjected to a high thermal load in the region of the fire deck and valve bridge, and the temperature is reduced.

In one variant of the invention, the ring segment extends around the cylinder axis at a first angle, the first angle being between 20 and 180, preferably between 30 and 90, particularly preferably between 40 and 90, Deg.] To 50 [deg.]. The projecting portion extends about a second angle around the cylinder axis, and the second angle is 5 to 45 degrees, preferably 5 to 20 degrees. Conveniently, the second angle is less than the first angle.

It is particularly advantageous that the overflow opening starting from the receiving sleeve is arranged so as to extend preferably in the direction of the outlet channel between the two outlet valves. As a result, the entire coolant flow in the upper cooling compartment is concentrated at the outlet side, and improved cooling for the outlet channel wall and outlet valve guide is achieved. Also, due to the concentrated flow through the outlet side, the flow through the inlet side is slightly reduced. This results in a slight increase in temperature at the inlet valve bridge, which results in a very well balanced temperature level across the entire fire deck, resulting in a dramatic reduction in material stress.

If the width of the ring segment portion extending in the radial direction (direction starting from the cylinder axis) is smaller than the width extending in the circumferential direction of the projecting portion, a particularly concentrated flow with favorable cooling trough can be obtained. In other words, the width of the ring segment portion is defined as a radial extension, and the width of the protruding portion is defined as an extension in the circumferential direction around the cylinder axis.

The ring segment has a larger extension in the circumferential direction around the cylinder axis (hereinafter referred to as the length of the ring segment) than in the radial direction (radial extension, hereinafter referred to as the width of the ring segment). Alternatively, the protruding portion has a larger radial extension (hereinafter referred to as the length of the protruding portion) than the circumferential direction around the cylinder axis (this circumferential extension is hereinafter referred to as the width of the protruding portion). Wherein the overflow opening is substantially between two connecting lines extending from the cylinder axis to the respective valve axis of two other valves, preferably between the connecting line from the cylinder axis to the outlet valve axis of the two outlet valves around the cylinder axis A configuration favorable to the flow conditions is obtained. In one variant of the invention, the projecting portion extends along a valve symmetry plane extending perpendicularly to the fire deck between the two valve axis, preferably between the outlet valve axis of the outlet valve. Advantageously, the extension of the projecting portion ends radially in front of the connecting surface between the two valve axes. As a result, a favorable balance between the cooling effect and the strength of the cylinder head is obtained.

Advantageously, the projecting portion extends in a direction away from the cylinder axis through a radial cooling channel extending through the outlet valve bridge. As a result, the area subject to the high thermal load of the outlet valve bridge can be particularly effectively cooled.

For good cooling it is also preferred that said overflow opening is connected to a cooling channel which runs radially away from the distribution ring in the lower cooling compartment through a distribution ring arranged in said lower cooling compartment around the receiving sleeve It is advantageous. As a result, the flow around the receiving sleeve in the lower cooling compartment can take place in an intended manner.

The object of the present invention is also achieved by the first-mentioned internal combustion engine having a cylinder head according to one of the above-described modifications.

The invention will now be described in more detail with reference to the non-limiting exemplary embodiments shown in the drawings.

Fig. 1 schematically shows a cylinder head according to the present invention in cross section along a line I-I in Fig. 2. Fig.
Fig. 2 is a sectional view of the cylinder head of Fig. 1 taken along the line II-II in Fig. 1 in the region of the upper cooling compartment.
Fig. 3 is a cross-sectional view of the cylinder head of Fig. 1 taken along the line III-III in Fig. 1 in the region of the lower cooling compartment.

1 shows a cross-section of an internal combustion engine 100 with a liquid-cooled cylinder head 1 having at least one cylinder (not shown) arranged along a cylinder axis 2. The cylinder head 1 has a fire deck 3 in the direction of the combustion chamber of the cylinder. The intermediate deck 4 divides the cooling chamber device 5 into a lower cooling compartment 5a near the fire deck 3 and an upper cooling compartment 5b adjacent in the direction of the cylinder axis 2. [

The intermediate deck 4 has at least one overflow opening 6 per cylinder which is intended for the flow connection between the upper cooling compartment 5b and the lower cooling compartment 5a, And the receiving sleeve (7). The receiving sleeve 7 serves, for example, to receive a fuel injector or a spark plug, and is disposed substantially concentric with the cylinder axis 2. 2, the overflow openings 6 starting from the cylinder axis 2 are adjacent to each other in the radial direction between the receiving sleeves 7, and according to the invention, at least partly in the axial direction of the cylinder axis 2 or the receiving sleeve 7 and has an additional protruding portion 6b having a circular ring segment portion 6a extending therefrom and extending in the radial direction. In an embodiment, favorable dispersion and cooling of the coolant is achieved particularly for top-down cooling, that is to say for areas which are subjected to particularly high thermal stresses, as the coolant flows from the upper cooling compartment 5b into the lower cooling compartment 5a .

The ring segment 6a is in the form of a circular ring segment and extends circumferentially around the cylinder axis 2 or the receiving sleeve 7 at a first angle a. The first angle [alpha] is 20 [deg.] To 180 [deg.], And in the illustrated exemplary embodiment is an angle of about 65 [deg.]. The substantially radially extending protruding portion 6b extends circumferentially at a second angle beta which is between 5 and 45 degrees and in the illustrated exemplary embodiment is approximately 16 degrees .

The second angle beta is preferably smaller than the first angle alpha. In this way, the coolant can be directed in an intended manner, particularly in the region of the valve shaft receiving a high thermal load at the outlet side.

In addition to the above angular range in the circumferential direction around the cylinder axis 2, it is also necessary to consider a radial extension starting from the cylinder axis 2. In all embodiments, the ring segment portion 6a has a larger extension in the circumferential direction than in the radial direction. In this case, the radial extension is the width of the ring segment portion 6a. The protruding portion 6b can be designed differently according to the embodiment. The width of the protruding portion 6b, that is, the circumferential extension around the cylinder axis 2 may be smaller than, equal to or greater than the extension of the protruding portion 6b (starting from the cylinder axis 2). In the illustrated exemplary embodiment according to Figs. 2 and 3, the width of the protruding portion 6b is substantially equal to the length, i.e. the radial extension. The width of the ring segment portion 6a extending in the radial direction is smaller than the width of the protruding portion 6b extending circumferentially about the cylinder axis 2, as is done in the illustrated exemplary embodiment , Advantageous coolant dispersion can be achieved when flowing through the overflow opening 6.

In order to achieve the best possible balance between the pressure loss when flowing through the overflow opening 6 and the cooling effect in the areas subjected to high thermal stresses such as the receiving sleeve 7 and valve bridge, The dimensions are selected as follows. The overflow opening 6 and in particular the ring segment 6a are arranged between the two connecting lines A extending from the cylinder axis 2 to the respective valve axis 8a, 8b of the two different valves. In principle, these may be outlet valve axis 8a and intake valve axis 8b, or each connection line A extending to outlet valve axis 8a and intake valve axis 8b. However, in the exemplary embodiment shown in FIG. 2, the connection line A is disposed between the cylinder axis 2 and the outlet valve axis 8a. This is advantageous because the highest thermal stress is generated at the outlet side during operation. The connecting line A is connected to the cylinder axis 2 as each valve axis line 8a, 8b. At the same time, the protruding portion 6b extends between the two valve axes 8a, 8b perpendicular to the fire deck 3 (between the outlet valve axis 8a in the exemplary embodiment shown) (Z). The valve symmetry plane Z extends in this case through the cylinder axis 2 perpendicularly to the fire deck 3 or the cylinder head sealing surface and parallel to the valve axis 8a, 8b. In the radial direction, the extension of the overflow opening 6, in particular the protruding portion 6b, ends before the connecting line between the two valve axes 8a, 8b, which is associated with the valve symmetry plane Z, In an embodiment, it is an outlet valve axis 8a.

In the figure, the flow of coolant in the cylinder head 1 according to the invention is indicated by the arrow P. 1, the coolant flows into the upper coolant compartment 5b through a coolant inlet from a pressure source (not shown), such as a coolant pump, Flows through the overflow opening 6 in the direction of the overflow opening 6 and directly bumps against the fire deck 3 to cool the fire deck.

3, the coolant is divided into four radial cooling channels 9a, 9b, 9c, 9d through the distribution ring 10 in the lower cooling compartment 5a and the openings 11a, 11b, 11c And 11d to flow into the crankcase. It will be appreciated that fewer radial cooling channels and fewer apertures may be provided.

Through the distribution ring 10, the intended flow around the receiving sleeve 7 and thus the cooling of the receiving sleeve is made possible. In this case, the radial cooling channels 9a, 9b, 9c and 9d are arranged in the region of the valve bridge in particular. The design of the overflow opening 6 with the ring segment portion 6a and the protruding portion 6b leads to the guidance of the coolant flow and in particular to the introduction of the outlet valve bridge 90, 1 radial cooling channel 9a is efficiently cooled. 2, the protruding portion 6b extends radially from the cylinder axis 2 through the first radial cooling channel 9a extending through the outlet valve bridge 90, As shown in Fig. Here, "through" is understood as a direction away from the first deck 3 along the cylinder axis 2. [ The first radial cooling channel 9a is part of the lower cooling compartment 5a and the protruding part 6b is formed in the area of the intermediate deck 4. On the other hand, on the other hand, the outlet valve bridge 90 is already further cooled in the region of the intermediate deck 4, on the other hand, a large amount of water is supplied to the first cooling channel 9a.

This guiding effect is improved by the arrangement of the openings 11a, 11b, 11c, and 11d, and the coolant flows into the crankcase from the cylinder head 1 through the openings.

The exit side can be intensively cooled in both the upper cooling compartment 5b and the lower cooling compartment 5a by the geometrical structure of the exemplary embodiment shown in the drawing and the outlet side arrangement of the overflow opening 6. [ Thus, the outlet channel 8 or exit channels in the area subject to a high thermal load in the outlet valve bridge 90, the outlet valve guides 7a and 7b (see FIG. 2) and then the fire deck 3 Optimal cooling is achieved. Thus, a uniform temperature level is obtained in the entire fire deck 3, and therefore, a lower material stress is generated in the cylinder head 1. The term "valve bridge" or "outlet valve bridge 90" refers to material accumulation between a gas exchange valve (not shown) and an outlet valve. The outlet valve bridge 90 is subjected to a high thermal load.

In addition to the example shown in the embodiment of the drawings, other examples are possible, for example, the protruding portion 6b may be disposed in the region of the intake valve bridge or the intake-outlet valve bridge, A ring segment portion of < / RTI >

In this way, the present invention can increase the flow velocity at the transition between the cooling compartments 5a, 5b and, as a result of this concentrated flow, especially due to the projecting portion 6b, The cooling for the region subjected to a high thermal load in the region of the outlet valve bridge 90 is improved and therefore the temperature is lowered. As a result, thermal stress on the cylinder head and thus damage are prevented.

Claims (10)

CLAIMS 1. A cylinder head (1) of a liquid cooled internal combustion engine, wherein a cylinder head (1) has a cooling chamber device (5) adjacent to a fire deck (3) And the upper cooling compartment 5b is divided into a lower cooling compartment 5a and an upper cooling compartment 5b by the intermediate deck 4 disposed substantially parallel to the cylinder axis 2 The upper cooling compartment 5b and the lower cooling compartment 5a are disposed on one side of the intermediate deck 4 facing toward the side away from the fire deck 3 in the direction of the cylinder axis 2, The overflow opening 6 is preferably arranged adjacent to the receiving sleeve 7 and the overflow opening 6 is connected to the cylinder axis 2 via at least one overflow opening 6, At least one ring segment portion (6 < RTI ID = 0.0 > and a projecting portion (6b) starting from the ring segment portion and facing away from the cylinder axis (2) in the radial direction. The method according to claim 1,
The ring segment 6a extends around the cylinder axis 2 at a first angle a with a first angle of between 20 and 180, preferably between 30 and 90, 40 ° to 50 °. 3. The method according to claim 1 or 2,
Wherein the projecting portion 6b extends over a second angle beta about the cylinder axis 2 and the second angle is between 5 DEG and 45 DEG, preferably between 5 DEG and 20 DEG. One). 4. The method according to any one of claims 1 to 3,
The projecting portion 6b extends around the cylinder axis 2 over a second angle beta and the second angle is smaller than the first angle alpha. 5. The method according to any one of claims 1 to 4,
A width of the ring segment portion (6a) extending in the radial direction (direction starting from the cylinder axis (2)) is smaller than a width extending in the circumferential direction of the protruding portion (6b). 6. The method according to any one of claims 1 to 5,
The overflow opening 6 is substantially between two connecting lines A extending from the cylinder axis 2 to the respective valve axis 8a and 8b of two different valves, preferably between the cylinder axis 2 and the two connecting lines A, And extends circumferentially around the cylinder axis (2) between the connecting line (A) to the outlet valve axis (8a) of the two outlet valves. 7. The method according to any one of claims 1 to 6,
The projecting portion 6b has a valve symmetry plane Z extending perpendicularly to the fire deck 3 between the two valve axis lines 8a and 8b and preferably between the outlet valve axis 8a of the outlet valve (1). 8. The method according to any one of claims 1 to 7,
The projecting portion 6b extends in the direction away from the cylinder axis 2 through the radial cooling channels 9a, 9b; 9c; 9d extending through the valve bridge, in particular through the outlet valve bridge 90 , The cylinder head (1). 9. The method according to any one of claims 1 to 8,
The overflow opening 6 extends radially from the distribution ring 10 in the lower cooling compartment 5a through a distribution ring 10 arranged in the lower cooling compartment 5a around the receiving sleeve 7, (9a, 9b, 9c, 9d) running away from the cylinder head (1). An internal combustion engine (100) having the cylinder head (1) according to any one of claims 1 to 9.

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