JP4172338B2 - V-type internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a V-type internal combustion engine suitably used for an automobile.
[0002]
[Prior art]
Patent Document 1 and Patent Document 2 disclose a technique for improving the earthquake resistance by bridging a reinforcing top plate and a stay on opposite walls of the left and right banks of the V-type internal combustion engine.
[0003]
[Patent Document 1]
JP-A-11-107770 [0004]
[Patent Document 2]
Japanese Utility Model Publication No. 7-17957
[Problems to be solved by the invention]
In such a V-type internal combustion engine, the cylinder in the left bank (cylinder bore) and the cylinder in the right bank are offset in the direction of the cylinder row, so that the cylinder head is shared by a head fixing bolt at the upper part of the cylinder block. When tightening and fixing, the cylinder bore tends to deform into an approximately oval shape.
[0006]
In addition, in a V-type internal combustion engine having a structure in which one intake manifold having a bifurcated shape is fixed to upper portions of two cylinder heads of the left and right banks using a manifold fixing bolt, generally, the intake manifold and the two cylinder heads are used. And the mating surface is inclined with respect to the bolt axis. For this reason, when the manifold fixing bolt is tightened, the intake manifold sinks, the cylinder heads of the left and right banks are pushed away from each other, and the cylinders of the cylinder block tend to deform.
[0007]
The above-described Patent Document 1 and Patent Document 2 do not take much consideration on the deformation of the cylinder caused by the bolt axial force peculiar to the V-type internal combustion engine. Such deformation of the cylinder cannot be sufficiently suppressed.
[0008]
The present invention has been made in view of such problems, and has as its main purpose to effectively suppress the deformation of the cylinder caused by the bolt axial force or the like in the V-type internal combustion engine.
[0009]
[Means for Solving the Problems]
A plurality of stays are bridged between two opposing walls facing each other across a bank valley between the left and right banks of the cylinder block of the V-type internal combustion engine. All of the plurality of stays are inclined in the direction opposite to the inclination direction of the offset line connecting the centers of a pair of cylinders facing each other across the bank valley with respect to the engine width direction orthogonal to the cylinder row direction.
[0010]
【The invention's effect】
According to the present invention, the plurality of stays spanned between the opposing walls of the cylinder block are inclined in the direction opposite to the offset line with respect to the engine width direction. An irregular deformation can be effectively suppressed.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
[0012]
1 to 7 show a V-type 6-cylinder internal combustion engine according to a first embodiment of the present invention. As shown in FIG. 1, the internal combustion engine includes a cylinder block 10, a right bank cylinder head 12R and a left bank cylinder head 12L, which are fastened to the upper portion of the cylinder block 10 by a plurality of head fixing bolts 11. A plurality of manifold fixing bolts 13 and one intake manifold 14 that is fastened and fixed to the upper portions of the two cylinder heads 12R and 12L.
[0013]
As shown in FIG. 2, the cylinder block 10 includes six # 1 to # 6 cylinders (cylinder bores) 16 that are cast by, for example, aluminum die casting and are inclined at a predetermined bank angle (for example, 60 °). The # 1, # 3, and # 5 cylinders open to the flat head mounting surface 17R of the right bank, and the # 2, # 4, and # 6 cylinders open to the flat head mounting surface 17L of the left bank. The right bank is offset from the left bank by a predetermined amount in front of the engine Fr. Eight head bolt bosses 18 each having an internal thread into which the head fixing bolt 11 is screwed are formed in each of the head mounting surfaces 17R and 17L. These head bolt bosses 18 are arranged alternately with the cylinders so as to be located at the four corners of each cylinder.
[0014]
As shown in FIG. 3, each cylinder head 12R, 12L is cast from, for example, an aluminum alloy, and eight head bolt through holes 19 through which the head fixing bolt 11 passes are formed. A flat manifold attachment surface (mating surface) 20 to which the intake manifold 14 is attached is formed on the side wall of each cylinder head 12R, 12L on the bank valley 15 side. In each manifold mounting surface 20, three intake ports 21 and four manifold bolt bosses 22 are alternately formed. Each manifold bolt boss 22 is formed with a female screw into which the manifold fixing bolt 13 is screwed.
[0015]
As shown in FIG. 4, the intake manifold 14 is integrally cast from, for example, an aluminum alloy, and has a shape in which a tubular intake branch 23 connected to the intake port 21 branches into a bifurcated shape, and lower end portions on both sides thereof. In addition, an injection valve boss 24 to which the fuel injection valve is attached and a manifold bolt through boss 25 through which the manifold fixing bolt 13 passes are formed.
[0016]
Referring to FIG. 5, the axial direction of manifold mounting bolt 13 is set to substantially coincide with engine up-down direction C1. The manifold mounting surface 20 is inclined with respect to the bolt axial direction C1. That is, the manifold mounting surfaces 20 of both cylinder heads 12R and 12L have a substantially wedge shape and an arrowhead shape when viewed in the cylinder row direction. Therefore, by the bolt axial force F along the engine vertical direction C1, the first component force F1 along the manifold mounting surface 20 and the second component force F2 orthogonal to the first component force F1 act, and mainly the above-mentioned As the bolt axial force F increases, the intake manifold 14 sinks due to the second component force F2, and the cylinder heads 12R and 12L are pushed away from each other. Finally, the cylinder (cylinder bore) 16 of the cylinder block 10 is pushed. There is a problem peculiar to the V-type internal combustion engine that greatly affects the deformation of the engine.
[0017]
FIG. 6 is a top view corresponding to the head mounting surfaces 17R and 17L of the left and right banks of the cylinder block on the same surface, and FIG. 7 is a top view of the cylinder block. As shown in FIG. 6, the # 1, # 3, and # 5 cylinders in the right bank are offset from the # 2, # 4, and # 6 cylinders in the left bank by a predetermined amount to the engine front Fr. Accordingly, the offset line L1 connecting the centers of a pair of cylinders (for example, # 1 cylinder and # 2 cylinder) facing each other across the bank valley 15 is in the engine width direction C3 orthogonal to the cylinder row direction (engine longitudinal direction) C2. It is inclined. Thus, the cylinders in the left and right banks being offset in the cylinder row direction C2 has a great influence on the deformation of the cylinder bore due to the bolt axial force of the head fixing bolt 11.
[0018]
In FIG. 6, the broken line H1 exaggerates the intermediate virtual deformation state of the cylinder bore due to the bolt axial force of the head fixing bolt 11, and the solid line H2 exaggerates the final virtual deformation state of the cylinder bore due to the bolt axial force of the manifold fixing bolt 13. As shown. The major axis H3 is the major axis in the final virtual deformation state H2, and corresponds to the direction in which the deformation is most expanded in the final virtual deformation state H2. These deformation states H1 and H2 correspond to the case where stays 31 to 36 of the present embodiment described later are not provided. In the final virtual deformation state H2, most of the cylinders (especially # 2 to # 5 cylinders) are deformed into an oblong shape, and in particular, the major axis H3 is inclined with respect to the engine width direction C3 as an offset line L1. It is inclined in the same direction as the direction.
[0019]
In the present embodiment, in order to effectively suppress such distorted deformation of the cylinders, a total of six reinforcing stays 31 to 61 spanning the pair of opposing walls 28 on the bank valley 15 side in the cylinder block 10. 36 is integrally formed. Note that the stays 31 to 36 are not shown in FIGS. 1 and 2 for the sake of simplicity.
[0020]
The stays 31 to 36 have, as a common feature, extending toward one of the head bolt bosses 18 on the bank valley side to be reinforced, and the inclination direction of the offset line L1 with respect to the engine width direction C3. Inclined in the opposite direction. That is, the offset line L1 is inclined toward the upper right with respect to the engine width direction C3 extending in the vertical direction in FIG. 6, and the stays 31 to 36 are inclined toward the upper left.
[0021]
In addition, the stays 31 to 36 are eight first to first on the bank valley 15 side that is orthogonal to the long axis H3 of one cylinder 16 in the final virtual deformation state H2 and is located around the cylinder 16. It is set so as to substantially coincide with stay center lines 31a to 36a passing through one of the eight head bolt bosses 18-1 to 18-8.
[0022]
More specifically, the stay center line 31a of the first stay 31 passes through the third head bolt boss 18-3 immediately before the engine of the # 3 cylinder and is orthogonal to the long axis H3 of the # 3 cylinder. A stay center line 32a of the second stay 32 passes through the second head bolt boss 18-2 immediately in front of the engine of the # 2 cylinder and is orthogonal to the long axis H3 of the # 2 cylinder. The stay center line 33a of the third stay 33 passes through the fifth head bolt boss 18-5 immediately before the engine of the # 5 cylinder and is orthogonal to the long axis H3 of the # 5 cylinder. The stay center line 34a of the fourth stay 34 passes through the fourth head bolt boss 18-4 immediately behind the engine of the # 2 cylinder and is orthogonal to the long axis H3 of the # 2 cylinder. The stay center line 35a of the fifth stay 35 passes through the seventh head bolt boss 18-7 immediately behind the engine of the # 5 cylinder and is orthogonal to the long axis H3 of the # 5 cylinder. The stay center line 36a of the sixth stay 36 passes through the sixth head bolt boss 18-6 immediately behind the engine of the # 4 cylinder and is orthogonal to the long axis H3 of the # 4 cylinder.
[0023]
By providing such stays 31 to 36, the head fixing bolt 11 and the manifold fixing bolt 13 are tightened, and the cylinder bore 16 is deformed by the bolt axial force, in particular, the final virtual deformation state H2 of the # 2 to # 5 cylinders. Can be effectively suppressed from being deformed into a long oval shape in the direction of the offset line L1.
[0024]
In particular, the # 2 cylinder located closest to the engine front in the left bank near the engine and the # 5 cylinder located closest to the engine rear in the right bank near the engine sandwich the bank valley 15 therebetween. Since there is no port for receiving the reaction force from the cylinder head side of the opposing # 1 and # 6 cylinders, the degree of deformation in the final virtual deformation state H2 is relatively large and the need for reinforcement is high . Stays 32 to 35 are provided for all of the head bolt bosses 18-2, 18-4, 18-5, and 18-7 on the bank valley 15 side located around the # 2 and # 5 cylinders. Therefore, deformation of the # 2 cylinder and the # 5 cylinder can be intensively suppressed.
[0025]
Among the first to eighth head bolt bosses 18-1 to 18-8 on the bank valley 15 side, the first head bolt boss 18-1 located closest to the engine front side and the eighth head located closest to the engine rear side The bolt boss 18-8 is not provided with a stay. However, the # 1 cylinder located closest to the engine front and the # 6 cylinder located closest to the engine rear side are the other # 2- # because the front wall 26 and the rear wall 27 of the cylinder block 10 function as reinforcing ribs. The degree of deformation due to the bolt axial force is relatively small compared to the 5-cylinder, and the necessity for reinforcement is relatively low, so that the expected strength and rigidity can be ensured without providing a stay. In other words, weight reduction and simplification can be achieved by omitting the stay.
[0026]
FIG. 8 is a top view of the cylinder block of the V-type internal combustion engine according to the second embodiment of the present invention. In addition, the description which overlaps with the said 1st Example is abbreviate | omitted. In this embodiment, for the sake of simplicity, the six stays 41 to 46 are set substantially in parallel. However, as in the first embodiment, the inclination direction of the stays 41 to 46 is opposite to the inclination direction of the offset line L1 (see FIG. 6) with respect to the engine width direction C3. The stays 41 to 46 extend toward one of the second to seventh head bolt bosses 18-2 to 18-7 on the bank valley 15 side.
[0027]
As described above, the present invention has been described based on the specific embodiments. However, the present invention is not limited to the above-described embodiments, and includes various modifications and changes without departing from the spirit of the present invention. . For example, the present invention can be applied to a V-type 8-cylinder internal combustion engine.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a V-type six-cylinder internal combustion engine according to a first embodiment of the present invention.
FIG. 2 is a perspective view of the cylinder block of FIG.
3 is a perspective view of the cylinder head of FIG. 1. FIG.
4 is a perspective view of the intake manifold of FIG. 1. FIG.
FIG. 5 is a front view of the internal combustion engine of FIG. 1;
6 is a top view corresponding to the cylinder block of FIG. 1. FIG.
7 is a top view of the cylinder block of FIG. 1;
FIG. 8 is a top view of a cylinder block of a V-type six-cylinder internal combustion engine according to a second embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Cylinder block 11 ... Head fixing bolt 12R, 12L ... Cylinder head 13 ... Manifold fixing bolt 14 ... Intake manifold 15 ... Bank valley 16 (# 1- # 6) ... Cylinder (cylinder bore)
18 ... Head bolt boss 20 ... Manifold mounting surface (mating surface)
28 ... Opposing walls 31-36 ... Stay

Claims (6)

A plurality of stays are spanned across a pair of opposing walls across the bank valley between the left and right banks of the cylinder block,
All of the plurality of stays are inclined in the direction opposite to the inclination direction of the offset line connecting the centers of a pair of cylinders facing each other across the bank valley with respect to the engine width direction orthogonal to the cylinder row direction. organ. In the cylinder block, a plurality of head bolt bosses through which a head fixing bolt for fastening and fixing the cylinder block and the cylinder head are inserted are provided around the cylinder.
The V-type internal combustion engine according to claim 1, wherein the stay extends toward one of the head bolt bosses on the bank valley side. 3. The V-shape according to claim 2, wherein, among the head bolt bosses on the bank valley side, the stay is provided with respect to the head bolt bosses excluding the head bolt boss closest to the engine front and the head bolt boss closest to the engine rear. Internal combustion engine. 4. The V-type internal combustion engine according to claim 2, wherein the stay is orthogonal to a major axis in a final virtual deformation state of the cylinder by a bolt axial force of the head fixing bolt. 5. The V-type internal combustion engine according to claim 1, wherein all of the plurality of stays are parallel. Two cylinder heads fixed to the top of the cylinder block;
An intake manifold fixed to the upper part of the two cylinder heads by a plurality of manifold fixing bolts;
The V-type internal combustion engine according to any one of claims 1 to 5, wherein a mating surface between the intake manifold and the cylinder head is inclined with respect to an axis of the manifold fixing bolt.

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