JP2525251Y2 - Cylinder block of internal combustion engine for four-wheel drive vehicle - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder block of an internal combustion engine for a four-wheel drive vehicle in which a transfer for rear-wheel drive is juxtaposed.

2. Description of the Related Art As shown in FIG. 3, in a four-wheel drive vehicle in which an internal combustion engine 1 is mounted horizontally in an engine room at the front of the vehicle, the front wheels are driven via a transaxle 2 and Power is taken out by a transfer 3 connected to the transaxle 2, and the rear wheels are driven via a propeller shaft 4. Therefore, the transfer 3 is provided on the side of the internal combustion engine 1, more specifically, on the side behind the vehicle.
Are juxtaposed (see JP-A-61-119424).

FIG. 2 shows a conventional cylinder block 11 of the internal combustion engine 1. The cylinder block 11 has a plurality of cylinder bores 12 formed in series at an upper portion thereof and a lower deck located at a lower end of the cylinder bore 12. Skirts 14 and 15 extending to the left and right are connected to the side edge of the portion 13, and a bulkhead 16 is formed between the cylinders so as to support the skirts 14 and 15 from inside. The skirt portions 14 and 15 are slightly bulged outwardly in a convex shape, and have a deep skirt shape extending below the crankshaft 17, and have oil pan mounting flange portions 18 and 19 are formed. A relatively shallow oil pan 20 is mounted on the oil pan mounting flanges 18 and 19, and defines a crank chamber 21. The crankshaft 17 is supported between the bulkhead 16 and the bearing cap 22.

Here, the skirt portions 14, 15 and the oil pan mounting flange portions 18, 19, and further the bulkhead 16, etc.
It is configured substantially symmetrically about a reference plane M including the two center lines and the center line of the crankshaft 17.

The transfer 3 is transferred via a transfer gusset 25 connected to the cylinder block 11 with bolts 24.
The transfer 3 is provided on one side of the skirt portion 14, specifically, on an oil pan mounting flange portion 18.
It is located near the side of.

Problems to be Solved by the Invention As described above, the conventional cylinder block 11 does not particularly consider the mounting of the transfer 3 and basically uses the cylinder block of the internal combustion engine used for a front wheel drive vehicle or the like. ing. Therefore, transfer 3
Since it is attached to the outside of the greatly expanded skirt portion 14 and the oil pan attachment flange portion 18, it is located at a considerable distance from the crankshaft 17. That is, the distance H between the center of the transfer 3 and the center of the crankshaft 17 becomes very large.

Therefore, transfer 3 by cylinder block 11
Of the transfer 3 is reduced, and the transfer 3 is easily vibrated by the vibration of the engine. Conversely, the skirt portion on the side supporting the transfer 3 receiving the vibration of the transfer 3
14 is likely to vibrate, and the synergistic combination of them will increase the vibration and noise of the entire drive system.

Means for Solving the Problems In order to solve the above problems, the present invention has a deep skirt type skirt portion, which is mounted on a vehicle in a horizontal state, and a rear skirt portion is provided on one side of the skirt portion. In a cylinder block of an internal combustion engine for a four-wheel drive vehicle in which a wheel drive transfer is juxtaposed, a distance from a reference plane including a cylinder bore centerline and a crankshaft centerline to a skirt portion on a side opposite to the transfer is set at a lower end. Of the skirt portion on the side where the transfer is mounted, the distance from the reference surface toward the oil pan mounting flange portion at the lower end is formed. The skirt portion at the lower end of the skirt portion on the transfer side is formed so as to gradually decrease in size in accordance with Place the oil pan mounting flange closer to the reference surface than the oil pan mounting flange on the opposite skirt,
The transfer housing is disposed outside the oil pan mounting flange on the transfer side.

Function By shifting the transfer-side skirt portion and the like toward the center of the crankshaft as described above, the transfer can be arranged closer to the crankshaft.
Further, since the other skirt portion and the like are relatively widened outward, the oil amount of the oil pan and the return of the lubricating oil along the inside of the skirt portion are ensured in the same manner as the conventional one. Then, the rigidity of the skirt portion on the transfer side is increased, and the skirt portion is less likely to vibrate.

Embodiment One embodiment of the present invention will be described below in detail with reference to FIG.

The cylinder block 31 is integrally formed of cast iron, an aluminum alloy, or the like, and has a plurality of cylinder bores 32 arranged in series at an upper portion, and a lower deck portion 33 located at a lower end of the cylinder bore 32. The skirt portions 34 and 35 extending right and left are connected to each other, and a bulkhead 36 is formed between the cylinders so as to support the skirt portions 34 and 35 from inside. The skirt portions 34 and 35 have a deep skirt shape extending below the crankshaft 37, and have oil pan attachment flange portions 38 and 39 formed at the lower ends thereof.

The transfer 3 is supported on one side of one skirt portion 34 via a transfer gusset 41 connected to the bulkhead 36 of the cylinder block 31 by bolts 40.

Here, the skirt portion 34 on the side to which the transfer 3 is attached is closer to the center of the crankshaft 37 than the skirt portion 35 on the opposite side. In the opposite skirt portion 35, the lower portion extends outward, whereas the lower end portion of the skirt portion 34 enters the inside along the trajectory of the counterweight 37a. The whole has a substantially arc-shaped cross section. More specifically, the skirt 35 on the side opposite to the transfer 3 gradually expands as the distance from the reference plane M including the center line of the cylinder bore and the center line of the crankshaft gradually increases toward the oil pan mounting flange 39 at the lower end. On the other hand, in the lower part of the skirt portion 34 on the side where the transfer 3 is mounted, the distance from the reference surface M gradually decreases toward the oil pan mounting flange portion 38 at the lower end. Thus, the cross-section is formed in a substantially circular arc shape centering on the center of the crankshaft 37. Further, the oil pan mounting flange portion 38 located at the lower end thereof is, as a matter of course, also located closer to the center of the crankshaft 37 than the oil pan mounting flange portion 39 on the opposite side. That is, it is arranged closer to the reference plane M than the oil pan mounting flange 39 on the opposite side. In addition, bulkhead
36 has both sides extending downward so as to support the oil pan mounting flanges 38 and 39.

That is, the skirt portions 34 and 35, the oil pan mounting flange portions 38 and 39, and the bulkhead 36 are configured to be left-right asymmetric about the reference plane M including the center line of the cylinder bore 32 and the center line of the crankshaft 37.

Then, the transfer 3 is connected to the crankshaft as described above.
37, the skirt portion 34 is offset toward the center, and the oil pan mounting flange portion 38 is disposed in proximity to the skirt portion 34. The transfer 3 is located below the crankshaft 37 as shown in FIG.
The housing of the transfer 3 is disposed substantially along the height of the flange portion 38.

A relatively shallow oil pan 42 is mounted on the oil pan mounting flanges 38 and 39, and
Although 46 is defined, the oil pan 42 is also left-right asymmetric.

The crankshaft 37 is supported between the bulkhead 36 and the bearing cap 43, and the bearing caps 43 are connected in the front-rear direction via the bearing beam 44. Here, the bearing beam 44 is
A pair of beam portions 44a, has the 44b, transfer 3 and opposite side of the beam portion 44b flange portion 39 and the bare-ring forms a gap W ₂ cap bolt 45 which is located sufficiently apart
The beam portion 44a on the transfer 3 side is located on the axis of the bearing cap bolt 45a, while the beam portion 44a on the transfer 3 side extends beyond the b. 38 and forms a small gap W ₁ and.

Note that, when the cylinder block 31 is mounted horizontally on a vehicle, the cylinder block 31 is slightly inclined so that the upper portion thereof is closer to the front with respect to the vertical line L. A lubricating oil return passage 47 for returning lubricating oil from the cylinder head (not shown) to the crank chamber 46 is provided on the front side of the vehicle, ie, on the side opposite to the transfer 3, which is inclined downward in this inclined state. I have.

In the above configuration, since the skirt portion 34 and the oil pan mounting flange portion 38 on the transfer 3 side are offset toward the center of the crankshaft 37, the transfer 3 can be arranged closer to the crankshaft 37. In particular, since the oil pan mounting flange portion 38 is deeper inward than the central portion of the skirt portion 34, the transfer gusset 41
Arm length is also reduced. Therefore, the rigidity of supporting the transfer 3 by the cylinder block 31 is improved, and the vibration of the transfer 3 is suppressed.

The skirt portion 34 on the transfer 3 side has a substantially arcuate cross section as a whole, and is substantially spherical between the cylinders when viewed three-dimensionally. Vibration and noise generated can be suppressed. In addition, as a result, vibration transmitted to the oil pan 42 serving as a secondary sound source via the oil pan mounting flange portion 38 at the lower end is reduced.

Therefore, vibration and noise of the entire drive system can be greatly suppressed as compared with the conventional one.

Further, since the counterweight 37a and the skirt portion 34, and the flange portion 38 and the beam portion 44a of the crankshaft 37 rotating in the direction of the arrow A in the drawing are close to each other, the lubricating oil in the oil pan 42 is suppressed from being lifted up. In addition, the scattered lubricating oil is prevented from scattering upward.

On the other hand, since the skirt portion 35 and the oil pan mounting flange portion 39 on the opposite side to the transfer 3 are relatively swelled outward, the oil amount of the oil pan 42 can be sufficiently secured as in the conventional case. is there. The skirt 35 and the counterweight 37a, and the flange 39 and the beam 44b
There is sufficient clearance between the lubrication oil return passage 47
The lubricating oil is not prevented from falling into the oil pan through the oil pan.

Advantages of the Invention As is apparent from the above description, according to the cylinder block of the internal combustion engine for a four-wheel drive vehicle according to the invention, the transfer support stiffness can be increased, and the transfer-side skirt portion that resonates with the transfer. And the vibration and noise of the entire drive system due to the synergistic vibration of both the internal combustion engine and the transfer can be greatly suppressed. Also, the oil amount of the oil pan and the return of the lubricating oil can be ensured in the same manner as in the conventional case.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a cylinder block according to the present invention, FIG. 2 is a cross-sectional view showing an example of a conventional cylinder block, and FIG. 3 is an illustration showing a layout of a drive system of a four-wheel drive vehicle. FIG. 3 ... Transfer, 31 ... Cylinder block, 34,35
... Skirt, 36 ... Bulkhead, 38,39 ... Oil pan mounting flange.

Claims (1)

(57) [Scope of request for utility model registration] A skirt portion having a deep skirt type,
In a cylinder block of an internal combustion engine for a four-wheel drive vehicle in which a transfer for rear-wheel drive is mounted side by side on one side of a skirt portion while being mounted on a vehicle, a skirt portion opposite to the transfer The distance from the reference plane including the cylinder bore center line and the crankshaft center line is formed in an expanded shape that gradually increases toward the oil pan mounting flange portion at the lower end, and the skirt portion on the side where the transfer is mounted is formed. The lower part, so that the distance from the reference plane gradually decreases toward the oil pan mounting flange at the lower end,
It is formed in a substantially arcuate cross-section centered on the center of the crankshaft, and the oil pan mounting flange at the lower end of the transfer side skirt is closer to the reference surface than the oil pan mounting flange on the opposite skirt. A cylinder block for an internal combustion engine for a four-wheel drive vehicle, wherein a transfer housing is disposed outside the oil pan mounting flange portion on the transfer side.