JPS601248Y2 - automotive engine - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an in-line multi-cylinder automobile engine comprising a cylinder block in which the outer wall of a water jacket and a skirt portion are integrally cast.

Figure 1 shows 1. The cylinder block 1 shown in the figure below shows a half-skirt type cylinder block 1 in a conventional in-line multi-cylinder automobile engine, which is described in R1 Automobile Engineering Complete Book 4, Gasoline Engine (published by Sankaido), etc. The outer wall 4 of the water jacket 3 that surrounds the liner section 2 is approximately parallel to the center line of the liner section 2, while the skirt section 5 that forms part of the crank chamber is large enough to accommodate the connecting rod. The outer wall 4 and the skirt portion 5 are connected by an arc portion 6 having an appropriate radius.

Furthermore, within the skirt portion 5, there are a plurality of bearing holding portions 7.
are integrally formed, and the crankshaft is supported via bearing metal between the bearing caps 8 attached to the holding portions 7 and facing each other. In the conventional configuration, the coupling rigidity between the outer wall 4 of the cylinder block 1 and the skirt portion 5 at the arc portion 6 is insufficient, and the skirt portion 5 expands in an arc shape, so that the entire cylinder block 1 As a result, the cylinder block 1 itself tends to vibrate due to vibration input from the crankshaft resulting from combustion impact force.

In addition, since the bearing caps 8 are each provided independently, each bearing cap 8 tends to fall down in the front-rear direction (crankshaft direction) due to the combustion impact force, causing vibration, and as mentioned above, the cylinder in the vertical bending direction Since the rigidity of the block 1 is not sufficient, this falling vibration synergizes with the vibration of the cylinder block 1 itself, causing the skirt portion 5 to vibrate greatly.

Due to the structure of the skirt portion 5, these vibrations become membrane vibrations with the arc portion 6 as a fulcrum, which not only radiates significant noise to the outside, but also causes the oil pan, which is a secondary sound source, to vibrate. That's what happens.

Incidentally, such vibration noise is particularly noticeable when the cylinder tab suspension 1 is made of light alloy to reduce its weight.

This idea was made in view of these conventional problems, and the outer wall of the water jacket 5 and the skirt section are connected in a straight line, so that the overall cross-sectional shape of the outer wall of the water jacket and the skirt section is approximately trapezoidal. This aims to solve the above problems by improving the rigidity of the cylinder block against bending and torsion, while also connecting multiple bearing caps together via a beam to suppress their falling vibrations. .

Hereinafter, one embodiment of this invention will be described in detail based on FIGS. 2 to 6.

In the figure, reference numeral 11 indicates a cylinder block whose parts are integrally cast, and reference numeral 12 indicates a bearing beam attached to this cylinder block 11.

First, to explain the cylinder block 11, the liner section 13
The outer wall 15 of the water jacket 14 surrounding the fourth,
As shown in Figure 5, move the cylinder block 1 downward.
The outer wall 15 is formed to be inclined so as to gradually expand in the width direction, and a skirt portion 16 is continuously formed at the lower part of the outer wall 15.

The skirt portion 16 has an inclined, substantially linear shape similar to the outer wall 15, and is linearly continuous with the lower portion of the outer wall 15, and has a connecting rod large end portion and a counterweight inside. The crank chamber is formed so as to enclose the envelope X.

That is, as described above, the outer wall 15 and the skirt portion 16
By forming them in an inclined straight line, their entire cross-sectional shape becomes approximately trapezoidal as shown in FIGS. 4 and 5.

In addition, the width of the water jacket 14 is at least 6rrvn.
Since it is necessary to secure at least the liner part 1
In the vicinity of cross section A-A, which is the diameter portion of liner 13, the upper part of outer wall 15 forms a cylindrical surface having a cross section parallel to the center line of liner portion 13, as shown in FIG.

However, in the case where the width of the water jacket 14 can be ensured sufficiently, it is desirable that the water jacket 14 extends linearly from the upper part of the outer wall 15 to the skirt part 16.

Further, an oil pan mounting flange 17 is formed at the lower end of the skirt portion 16 and is made slightly wider in order to improve lateral bending rigidity, and a transmission mounting portion 18 is formed at the rear end.

In addition, in order to further improve the rigidity of the horizontal bending, as shown in FIG.
9 may be provided.

Furthermore, a plurality of bearing holding portions 20 having semicircular bearing fitting portions are integrally formed within the skirt portion 16 .

In addition, 21 is a screw hole 2 for mounting the cylinder head (not shown).
This boss portion 21 is integrally formed inside the outer wall 15 via a rib 23.

On the other hand, the bearing beam 12 includes a plurality of bearing cap parts 24 having semicircular bearing fitting parts,
The bearing cap portion 24 is composed of a beam portion 25 and ′ that integrally connects the bearing cap portion 24 at its lower part, and is, for example, both integrally cast.
The port 26 is connected to the shaft, and the crankshaft is supported here.

Incidentally, the bearing cap portion 24 and the beam portion 25 may be separate members, and the bearing beam 12 may be constructed by, for example, being coupled with bolts.

In the above configuration, the outer wall 15 and the skirt portion 16 are linearly continuous, and the overall cross-sectional shape is trapezoidal as shown in FIGS. 4 and 5, so that the rigidity of the cylinder block 11 itself in the vertical bending direction is reduced. In addition, in a state where the bearing beam 12 is connected by the action of the beam portion 25 located at the lower edge, the rigidity can be further improved.

Also, the beam portion 25 allows each bearing cap portion 2
4 is suppressed, and the vibration input to the skirt portion 16 due to this falling vibration is reduced, and since the skirt portion 16 is linearly continuous with the outer wall 15, membrane vibration in the expansion direction is suppressed. Moreover, since the skirt portion 16 is linear, the surface area from which noise is radiated is smaller than that of the conventional structure, and therefore, the noise radiated from the skirt portion 16 is significantly reduced.

Furthermore, noise from the oil pan is also reduced due to the reduction in vibration of the skirt portion 16.

The outer wall 15 also has rigidity against left and right bending, torsion, etc.
The cylinder block 11 itself has sufficient rigidity against left and right bending, torsion, etc., so that the beam part 25 does not need to take these into account. A sufficient effect can be achieved with a minimum size that suppresses the falling vibration of the bearing cap portion 24, and noise reduction can be achieved extremely effectively without compromising the weight reduction of the engine.

As is clear from the above explanation, according to this invention, the cross-sectional shape of the cylinder block is approximately trapezoidal, and a beam serving as a reinforcing member is provided at the lower edge, so that the basic rigidity against bending, twisting, etc. Effective improvement can be achieved, and in particular, the vertical bending rigidity can be greatly improved by the cooperation of the two.

Since the beam does not need to take into account lateral bending rigidity, etc., it can be relatively lightweight, and the beam can suppress the vibration of the bearing cap from falling down without compromising the weight reduction of the engine. Together with the effect of improving rigidity, the noise radiated to the outside from the engine can be extremely effectively reduced.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a conventional cylinder block, Fig. 2 is a side view showing an embodiment of this invention, Fig. 3 is a plan view showing only a part of it, and Fig. 4 is an A in Fig. 3. - A sectional view, FIG. 5 is a sectional view partially taken along the B-B line, and FIG. 6 is a sectional view of the main part showing an example in which reinforcing ribs are provided. 11... Cylinder block, 12...
Bearing beam, 13... Liner section, 14.
・・・・・・・・・Water jacket, 15・・・・・・
・Outer wall, 16...Skirt part, 19...
・Reinforcement rib, 24...Bearing cap part,
25... Beam section.

Claims (1)

[Scope of utility model registration request] 1. An in-line multi-cylinder automobile engine comprising a cylinder block in which a water jacket outer wall surrounding a liner part to form a water jacket and a skirt part forming a crank chamber are integrally cast. The outer wall of the water jacket is formed to be inclined so as to gradually expand downward, and the scar part is similarly formed in an inclined substantially linear shape, and the lower part of the outer wall of the water jacket and the skirt are formed. The water jacket outer wall and the skirt section of the cylinder block are made to have a substantially trapezoidal cross-sectional shape, while the plurality of bearing caps attached to the bearing holding section of the cylinder block are connected to the beam. An automobile engine characterized by being integrally connected via a.