JPS61136014A - Support device for crankshaft of multicylindered internal combustion engine - Google Patents

Abstract

PURPOSE:To reduce vibration and noise of a crankshaft by considerably enlarging the rigidity of a support portion for the crankshaft. CONSTITUTION:A bearing cap 11 is fixed with a bridge member 14 to a journal wall 7 by a connecting bolt 20, and the bridge member 14 is further fastened to the journal wall 7 by a connecting bolt 21. As the connecting bolts 20, 21 are disposed adjacent to a crankshaft Sc in such a manner as to intersect the cylinder axis L1-L1 of a cylinder 1 and the cylinder axis L2-L2 of a cylinder 1, as a whole, plural bearing caps 11 and the bridge member 14 are firmly integral with the journal wall 7. In this arrangement, a portion where external force is imposed is concentratively strengthened so that on the whole, the rigid ity of a support portion for the crankshaft Sc is considerably high.

Description

DETAILED DESCRIPTION OF THE INVENTION A1 Object of the Invention (1) Field of Industrial Application The present invention relates to a crankshaft support device for an in-line or V-type multi-cylinder internal combustion engine.

(2) Prior art In conventional multi-cylinder internal combustion engines, the crankshaft is rotatably supported by a plurality of journal walls integrally formed in the crankcase of the cylinder block and bearing camps connected to these by connecting bolts. A structure in which these bearing caps are integrally connected by a bridge member is conventionally known (see Japanese Patent Publication No. 55-26282).

(3) Problems to be Solved by the Invention By the way, the crankshaft support device consisting of a bearing cap and a bridge member is a system in which the crankshaft is supported by a continuous bearing cap in which a plurality of bearing caps are integrally connected. Although it is superior in ease of assembly and maintenance compared to conventional products, it is undeniably inferior in rigidity, and there is a need to further improve the rigidity.

The present invention has been developed in view of the above circumstances, and the journal wall, bearing cap, and bridge member are firmly and integrally connected, and the rigidity of the crankshaft support part is extremely high. It is an object of the present invention to provide a novel crankshaft support device for a multi-cylinder internal combustion engine, which can also simplify the sealing part.

B0 Structure of the Invention (1) Means for Solving the Problems According to the present invention, in order to achieve the above object, bearing caps are fastened to a plurality of journal walls integrally formed in the crankcase of the cylinder block, In a crankshaft support device for a multi-cylinder internal combustion engine, the crankshaft is rotatably supported by a journal wall and a bearing cap, and a bridge member is fastened to the lower surface of a plurality of bearing caps, the bridge member comprising: The bridge member and the bearing cap extend in a direction perpendicular to the crankshaft across the bearing camp to the left and right sides of the journal wall, and the bridge member and the bearing cap are connected to a first
The bridge member is fastened to the journal wall using a connecting bolt, and the bridge member is fastened to the journal wall using a second connecting bolt. A second connection bolt is located inside the joint between the skirt wall of the crankcase and the oil pan.

(2) Effects According to the above configuration, the rigidity of the support part of the crankshaft is extremely high, so that the crankshaft does not vibrate or make noise for a long period of time.
It rotates smoothly and easily, and the sealing device between the crankcase and oil pan is simple.

(3) Embodiment Hereinafter, an embodiment in which the present invention is implemented in a V-type 6-cylinder internal combustion engine will be described with reference to the drawings.

The aluminum alloy cylinder blocks B of the internal combustion engine are arranged in a V-shape and have inclined cylinder axes, -L,
, two cylinders 11°12 with L2-L2,
Those cylinders 1. ．． It is composed of a crankcase 2 which integrally connects 12 collective lower parts.

The cylinders i, , i2 each have three cylinder bores 3. ．． 32 are arranged in series, the cylinders 1, . A water jacket 41.4° is formed on the wall 12 so as to surround the cylinder bore 31.3□.

The crankcase 2 includes a pair of left and right skirt walls 5. which face each other along the direction of the crankshaft 5c. .

5□ are integrally hung, and these skirt walls 5. .

At the lower end of 52 are mounting flanges 6, . 62 are integrally formed, and a cross section U is formed on the lower surface of their mounting flanges 67, 6□.
A letter-shaped oil pan PO is joined via a gasket, and lubricating oil is stored in the oil pan Po.

Four journal walls 7 are integrally formed in the crankcase 2 at intervals in the direction of the crankshaft 5t.

A recess 10 recessed inward and having a channel-like cross section is formed in the center of the lower surface of the journal wall 7 to fit a bearing gap 11, which will be described later. A semicircular bearing half 8 for supporting the recess 10 is formed, and a fitting female surface 12 is formed at the upper part of the opposing inner surface of the recess 10.

The recess 10 of the journal wall 7 is made of iron alloy.
A bearing cap 11 having a square cross section is fitted. This bearing cap 11 has a flat upper surface that joins the lower surface of the recess 10 of the journal wall 7, and another bearing half 9 corresponding to the bearing half 8 is formed at the center of this upper surface. Further, on the upper part of both side surfaces of the bearing camp 11 along the direction of the crankshaft 5c, a fitting male surface 1 that fits into the fitting female surface 12 is provided.
3 is formed. The female and male fitting surfaces 12 and 13 are closely fitted to each other to form a tight fitting portion E. The lower surface of the bearing cap 11 is also formed flat, and the lower surface is formed on the lower surface of the journal wall 7 and the skirt walls 54, 5.
The bottom surface of □ is the road surface.

A journal is provided on the lower surface of the plurality of journal walls 7 and the bearing cap 11, extending along the direction of the crankshaft SC, spanning the plurality of journal walls 7, and extending in a direction perpendicular to the crankshaft 5c. An aluminum alloy bridge member 14 spanning the wall 7 and the bearing cap 11 is positioned and fixed.

Next, the structure of the bridge member 14 and the journal wall 7
To explain the fixing structure to the bearing camp 11,
The bridge member 14 has a main portion 1 extending in the direction of the crankshaft.
5, and the plurality of bearing caps 11 from this main portion 15.
The baffle plate 17 is composed of a plurality of leg portions 16 that are integrally erected corresponding to the main portion 15 and a baffle plate 17 that extends from the main portion 15 to the left and right and connects the leg portions 16. The balance weight 18 of the crankshaft SC is formed to have an arcuate cross section so as to extend over the outer circumferential surface of the balance weight 18, and an oil return hole 27 is bored therein.

The upper surface of the plurality of leg portions 16 is provided with a bearing cap 11, respectively.
and is joined to the flat lower surface of the journal wall 7. A positioning pin 19 that also serves as an oil passage is installed at approximately the center of the left and right joints between the bearing cap 11 and the journal wall 7, spanning them.
are inserted and their relative positions determined.

On both sides of the aluminum alloy bridge member 14 orthogonal to the crankshaft SC, from the lower side of the bridge member 14,
A first connecting bolt 20 is screwed onto the journal wall 7 of the crankcase 2 through the bridge member 14 and the bearing cap 11, and the bridge member 14 and the bearing cap 11 are fastened together to the journal wall 7 by the first connecting bolt 20. be done. Further, a second connecting bolt 21 is fastened to the journal wall 7 through the bridge member 14 from below the bridge member 14 outside the first connecting bolt 20 . Therefore, the above-mentioned No. 1. The second connecting bolts 20.degree. 21 are substantially parallel to each other, and are close to the crankshaft 5C, and the first connecting bolts 20.degree.21 are located on the right side of the crankshaft S.rho. in FIG. The second connection port) 20.21 is connected to the cylinder 1. The cylinder axis of -L.

and the first one on the left side. Second connection bolt 20.
21 intersects the cylinder axis L2-L2 of the cylinder 12.

A main gear rally 22 is formed in the main portion 15 of the bridge member 14 in the longitudinal direction, and a plurality of leg portions 16 are formed in the main portion 15 of the bridge member 14.
Branch oil passages 23 branched from the main gear rally 22 extend upward, and each branch oil passage 23 passes through the oil passage in the positioning pin 19 and communicates with an oil supply passage 24 bored in the bearing cap 11. The oil supply passage 24 opens into the bearing surface of the bearing half 9.

A plurality of bearing holes 25 are formed by the bearing halves 8 and 9 formed in the journal wall 7 and the bearing cap 11, and the crankshaft S is inserted into these bearing holes 25 through a bearing metal 26.
The journal shaft portion of C is rotatably supported.

Next, the operation of the embodiment of the present invention will be explained.

Now, when a multi-cylinder engine employing the aluminum alloy cylinder block B is operated, the cylinder bore 3. .

The explosion pressure acting on the piston in 3
External forces such as bending force and torsional force act on the crankshaft 5tyVC, but the bearing cap 11 and the bridge portion 14 are jointly tightened and fixed to the journal wall 7 by the first connecting bolt 20, and the bridge member 14 is fastened to the journal wall 7 by a second connecting bolt 21, and the first one on the left and right side. 20.21 is the cylinder axis of cylinder 11, -L, and cylinder 1
Since the multiple bearing cap 11 and the bridge member 14 are disposed close to the crankshaft Sρ so as to intersect with the cylinder axis L2-12 of No. 2, the multiple bearing cap 11 and the bridge member 14 as a whole are firmly integrated with the journal wall 7, and are particularly susceptible to the action of the external force. The supporting parts of the crankshaft SC are strengthened intensively, and the rigidity of the supporting part of the crankshaft SC as a whole is extremely high, and the crankshaft SC rotates smoothly and easily with little vibration and noise.

Also, the above-mentioned No. 1. Since the second connection ports I-20 and 21 are both located inside the joint between the crankcase 2 and the oil pan Po, only one seal is required between the crankcase 2 and the oil pan Po. , the seal structure between the parts is simplified, and maintenance of the crankshaft support part is also easier.

Furthermore, since the cylinder block B and the bridge member 14 are both made of an aluminum alloy with the same coefficient of thermal expansion, it is necessary to increase the rigidity of the supporting part of the crankshaft SC. There is no fear that 11 will fall in the axial direction.

According to the present invention, bearing camps are fastened to a plurality of journal walls integrally formed in the crankcase of a cylinder block, and the crankshaft is fixed to a plurality of journal walls and a bearing cap. In a crankshaft support device for a multi-cylinder internal combustion engine, which is rotatably supported and further includes a bridge member fastened to the lower surface of a plurality of bearing caps, the bridge member straddles the bearing camp and extends between the right and left sides of the journal wall. The bridge member and the bearing cap are jointly fastened to the journal wall using a first connecting bolt, and the bridge member is further fastened to the journal wall using a second connecting bolt. ,
Said 1st. Since the second connecting bolt is located inside the joint between the skirt wall of the crankcase and the oil pan, the plurality of bearing caps 11 and the bridge member 14 are firmly integrated with the journal wall T, and the crankshaft bending force,
Even when external forces such as torsional force are applied, the crankshaft is reliably supported between the journal wall and the bearing cap, and there is little vibration and noise (it rotates smoothly and easily, and is able to cope with the high output of the engine). It is something.

In addition, the bearing camp and the fastening portion of the bridge member to the journal wall are located inside the crank chamber, and the crankcase and oil pan are joined independently of the fastening portion, making it easy to seal the joints. Not only that, but it also makes maintenance of the crankshaft support part easier.

[Brief explanation of the drawing]

The drawings show an embodiment of the device of the present invention; FIG. 1 is a longitudinal cross-sectional view thereof, FIG. 2 is a cross-sectional view taken along the line ■-■ in FIG. 1, and FIG. 3 is a cross-sectional view taken along the line ■-■ in FIG. It is a diagram. B...Cylinder block, SC...Crankshaft, PO
...Oil pan, 2...Crankcase, 5. ．． 52... Skirt wall, 7... Journal wall, 11... Bearing caliper, 14
・・・Bridge member

Claims (1)

[Claims] A bearing cap is fastened to multiple journal walls that are integrally formed in the crankcase of the cylinder block, and the crankshaft is rotatably supported by the multiple journal walls and the bearing cap, and a bridge is attached to the bottom surface of the multiple bearing caps. In a crankshaft support device for a multi-cylinder internal combustion engine in which a member is fastened to a bridge, the bridge member extends in a direction perpendicular to the crankshaft across the bearing cap to the left and right sides of the journal wall, and co-fastening the bridge member and the bearing cap to the journal wall using a first connecting bolt; further tightening the bridge member to the journal wall using a second connecting bolt; and tightening the first and second connecting bolts.
A crankshaft support device for a multi-cylinder internal combustion engine, characterized in that the device is located inside a joint between the skirt wall of the crankcase and the oil pan.