JPH11218118A - Crankshaft supporting structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the deformation of a cylinder block in crankshaft orthogonal direction in addition to the deformation thereof in the crankshaft direction in an engine having a structure without a rudder frame. SOLUTION: In this crankshaft supporting structure equipped with a plurality of bearing caps 14 supporting intermittently a crankshaft from its lower side along an axial direction and a bearing beam 15 by which the bearing caps 14 are connected to each other, a skirt connecting part 33 fastened to an approximately intermediate position among the bearing caps 14 in a skirt part 5 on both sides of the cylinder block 1, is formed on the bearing beam 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crankshaft support structure for supporting a crankshaft of an engine from below.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No. 9-144598 discloses a structure for supporting a crankshaft of an engine.
There is known a bearing beam in which adjacent bearing caps are connected from below with a beam material to suppress deformation of a cylinder block in a crank journal direction of a crank journal portion such as a bulkhead or a bearing cap.
Further, disclosed in Japanese Patent Application Laid-Open No. 4-50509, bearing caps are connected to each other by a ladder body extending to a skirt portion of a cylinder block, and in addition to deformation of the cylinder block in the crankshaft direction, the crankshaft is orthogonal. A ladder frame that also suppresses deformation of a cylinder block in a direction is known.

[0003]

The above-mentioned bearing beam can be easily applied to an existing engine, but cannot suppress deformation of the cylinder block in the direction perpendicular to the crankshaft. There has been a problem that vibration is generated, and vibration and noise are generated.

On the other hand, the above-mentioned ladder frame can suppress not only the deformation of the cylinder block in the direction of the crankshaft but also in the direction perpendicular to the crankshaft, so that the opening and closing vibration of the skirt portion can be prevented. A noise reduction effect is obtained. However, it is difficult to apply a ladder frame to an engine that has already been mass-produced and has a structure without a ladder frame, or a newly developed engine that is required to share manufacturing facilities with such an engine.

Accordingly, the present invention has been devised in order to solve the above-mentioned problem. An object of the present invention is to provide an engine having a structure without a rudder frame, in addition to deformation of a cylinder block in the direction of the crankshaft, as well as a crankshaft. An object of the present invention is to provide a crankshaft support structure capable of suppressing deformation in a direction perpendicular to an axis.

[0006]

In order to solve the above-mentioned problems,
The present invention provides a crankshaft support structure including a plurality of bearing caps for intermittently supporting a crankshaft from below along an axial direction and a bearing beam for connecting the bearing caps to each other. A skirt connecting portion is formed which is fastened at a substantially intermediate position between the bearing caps of the skirt portions on both sides of the cylinder block.

[0007] According to this, since the skirt connecting portion is formed on the bearing beam, the skirt portion can be fastened while the bearing beam can be easily applied to an existing engine. Therefore, in an engine having no ladder frame, deformation in the direction perpendicular to the crankshaft as well as deformation in the direction of the crankshaft can be suppressed, and opening and closing vibration of the skirt portion can be prevented. Further, since the skirt connection portion is formed to be fastened to a substantially intermediate position between the bearing caps of the skirt portions on both sides of the cylinder block, the antinode of open / close vibration of the skirt portion is fixed, which is the most effective. Vibration can be reduced.

The bearing cap is fastened to the cylinder block by a cap fastening bolt, the bearing beam is overlapped below the bearing cap and fastened together with the bearing cap by the beam fastening bolt, It is preferable to have an opening for exposing the cap fastening bolt.

According to this, since the cap fastening bolt is exposed to the outside, it is possible to assemble the crankshaft and the piston / connecting rod assembly during engine assembly.
In addition, the tightening of the cap fastening bolt can be easily performed.

The present invention also provides a crankshaft support structure having a plurality of bearing caps for supporting a crankshaft intermittently from below along the axial direction and a bearing beam for connecting the bearing caps to each other. The bearing beam is superimposed on the lower side of the bearing cap and fastened together to the cylinder block by a beam fastening bolt, and on both sides of the bearing beam, ridges that become valleys at the position of the bearing cap are formed. On the inner side of the valley, the bearing beam and the bearing cap are fastened together, and on both outer sides of the valley, the bearing cap is fastened to the cylinder block with cap fastening bolts, and the top of the ridge is , Between the bearing caps on the skirts on both sides of the cylinder block It is obtained by fastening skirt fastening bolt in a substantially intermediate position.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a bottom view showing an embodiment of a crankshaft support structure according to the present invention, and FIG. 2 is a longitudinal sectional view of the embodiment.

This embodiment relates to a crankshaft support structure for an aluminum V-type diesel engine.

1, the cylinder block 1 includes left and right banks 2a and 2b.
b, cylinder bores 3 are formed in parallel in the longitudinal direction. A skirt portion 5 is formed at a lower portion of the cylinder block 1. The skirt portion 5 extends along the longitudinal direction on both sides in the width direction at the lower end of the cylinder block 1.

Inside the skirt portion 5, a bulkhead 7 extending in the width direction of the cylinder block 1 and dividing each crank chamber 6 is formed integrally with the cylinder block 1.
The bulkhead 7 is formed in plural numbers at predetermined intervals in the longitudinal direction of the cylinder block 1, and is formed at four places in the present embodiment, and a lower end portion thereof supports the crank journal 9 of the crankshaft 8. A crank journal bearing member 10 made of cast iron is cast.

The bulkhead 7 has two inner bolt holes 11 into which beam fastening bolts 19 to be described later are inserted.
It is formed to extend in the vertical direction. This inner bolt hole 11
Are formed on both sides of the crankshaft 8,
Each has a female screw. This inner bolt hole 1
Two outer bolt holes 12 into which cap fastening bolts 18 to be described later are inserted are formed on both outer sides of the first bolt 1 so as to extend in the vertical direction, respectively. A female screw is formed in each of the outer bolt holes 12. These inner bolt holes 1
1 and the outer bolt hole 12 are both formed through the crank journal bearing member 10.

Inside the skirt portion 5 and below the bulkhead 7, a bearing cap 1 for intermittently supporting the crankshaft 8 at the position of the bulkhead 7 from underneath.
4 is fixed. The bearing cap 14 has a thickness substantially equal to that of the bulkhead 7, and is configured to sandwich and support the crank journal 9 of the crankshaft 8 together with the bulkhead 7.

In the bearing cap 14, a beam fastening bolt 1 is provided at a position corresponding to the above-described inner bolt hole 11.
An inner through-hole 16 is formed to allow the 9 to pass therethrough. At a position corresponding to the outer bolt hole 12 of the bulkhead 7, an outer through hole 17 for inserting a cap fastening bolt 18 is formed. Both the inner through-hole 16 and the outer through-hole 17 are formed in the longitudinal direction through the lower end surface and the upper end surface of the bearing cap 14.

A bearing beam 1 for connecting the bearing caps 14 is provided below the bearing cap 14.
5 is fixed to the lower side of the bearing cap 14 so as to overlap.

In the bearing beam 15, at a position corresponding to the inner through hole 16 of the bearing cap 14,
A cap fastening hole 21 for inserting the beam fastening bolt 19 is formed.

The bearing cap 14 is attached to the bulkhead 7 by inserting a cap fastening bolt 18 into the outer through hole 17 and inserting it into the outer bolt hole 12 and tightening. That is, the cap fastening bolt 18
Is for fastening only the bearing cap 14 to the bulkhead 7. Then, after the bearing beam 15 is superimposed on the lower side of the bearing cap 14, the beam fastening bolt 19 is connected to the cap fastening hole 21 and the inner through hole 1.
6, the bearing beam 15 is inserted into the inner bolt hole 11 and tightened.
4 attached. That is, the beam fastening bolt 1
Numeral 9 is for fastening the bearing cap 14 and the bearing beam 15 together.

Referring also to FIGS. 3 to 6, the bearing beam 15 is formed with cap coupling portions 22 which are superimposed on the lower side of the bearing caps 14, respectively. Is formed with a cap fastening hole 21. A concave portion 25 is formed on the upper surface of the cap connecting portion 22 to reduce the weight,
Ribs 26 are formed on the lower surface to improve the strength.

A cap connecting portion 23 is formed so as to bridge an adjacent cap connecting portion 22. The cap connecting portion 23 is formed in a plate shape so as to cover the lower side of the crank chamber 6.
An opening 24 is formed so that the crankshaft 8 can rotate.

On both sides in the width direction of the cap connecting portion 23, there are formed peaks 28 which become valleys 27 at the position of the bearing cap 14. That is, the peak portion 28 is formed by projecting the plate of the cap connecting portion 23 in the shape of a peak on both outer sides, whereby the skirt portion of the peak portion 28 becomes the valley portion 27. The valley portion 27 includes the cap connecting portion 22. The top portion 29 of the mountain portion 28 is located at a substantially intermediate position between the bearing caps 14 adjacent to the skirt portion 5 and serves as a skirt fastening portion 31 that is fastened to the skirt portion 5. A skirt fastening hole 34 is formed in the skirt fastening portion 31, and the skirt fastening portion 31 is fastened to the skirt portion 5 by a skirt fastening bolt 32. Therefore, the peak portion 28 serves as a skirt connecting portion 33 for connecting the skirt portion 5, and the skirt connecting portion 33 is formed on both sides of the bearing beam 15 in a continuous mountain shape. Will be done.

That is, the bearing beam 15 and the bearing cap 14 are fastened together by the beam fastening bolt 19 inside the valley portion 27, and the caps are opened at both open portions (open portions 37) outside the valley portion 27. Fastening bolt 1
8 fastens the bearing cap 14 to the cylinder block 1, and the cap fastening bolt 18 is exposed.

In particular, the top 29 of the peak 28 and the valley 27 are linearly connected. In addition, ribs 35 are formed below the skirt connecting portion 33 so as to be bridged between the skirt fastening hole 34 and the two adjacent cap fastening holes 21, respectively. Further, a rib 36 extending from the skirt fastening hole 34 to the opening 24 toward the inside is formed.

Next, the operation of the present embodiment will be described.

As described above, the formation of the ridge portion 28 serving as the skirt connection portion 33 in the cap connection portion 23 enables the bearing beam 15 to be easily applied to an existing engine or the like, but only the bearing cap 14 to be used. Instead, the skirt portion 5 can also be fastened. Therefore, not only the deformation of the cylinder block in the crankshaft direction but also the deformation of the cylinder block in the direction orthogonal to the crankshaft can be suppressed, and the opening and closing vibration of the skirt portion 5 can be prevented.

Particularly, in the present invention, the skirt fastening hole 34 of the skirt connecting portion 33 is formed at a substantially intermediate position between the adjacent bearing caps 14 of the skirt portion 5, so that the antinode of the opening and closing vibration of the skirt portion 5 can be reduced. The bearing beam 15 is fastened to the skirt portion 5, and the opening and closing vibration of the skirt portion 5 can be reduced most effectively.

The top 29 of the peak 28 and the valley 27 are linearly connected to each other, so that the stress of the vibration applied from the skirt 5 can be supported as an axial force, and the vibration can be more effectively reduced. Can be prevented. Thus, the top 29 and the valley 27
By connecting them linearly, simplification of the structure and improvement of the strength can be achieved at the same time. Furthermore, since the rib 35 bridged between the skirt fastening hole 34 and the two cap fastening holes 21 is formed in a truss shape, the strength of the bearing beam 15 can be improved, and further vibration can be achieved. Can be reduced.

Next, the operation of the present invention relating to the engine assembling procedure will be described.

First, the cylinder block 1 on which the bulkhead 7 is formed is set upside down.
After the crankshaft 8 is disposed on the bearing, the bearing cap 14 is put on the crankshaft 8 and fastened by cap fastening bolts 18.

Next, the cylinder block 1 is turned over,
The piston and connecting rod assembly is inserted from above the cylinder bore 3 and the large end of the connecting rod is attached to the crankshaft 8. At this time, the mounting work of the piston and connecting rod assembly is performed from the lower side of the cylinder block 1. However, since the bearing beam 15 covering the crankshaft 8 from below is not mounted yet, it is necessary to secure a work space for the mounting work. Workability is improved.

When the mounting of the piston and connecting rod assembly is completed, the bearing beam 15 is fastened together with the bearing cap 14 by beam fastening bolts 19 and fixed. In the subsequent steps, it may be necessary to retighten the bearing cap 14.
5 has an opening 37 for exposing the cap fastening bolts 18, so that even after the bearing beam 15 is attached, it is easy to retighten all the cap fastening bolts 18. Can be.

In particular, according to the above-described structure, the ridge portion 28 is formed so as to linearly connect the substantially intermediate position between the adjacent bearing caps 14 of the skirt portion 5 and the cap fastening portion 21. Can be used as the skirt connection portion 33, and at the same time, the cap fastening bolts 18 can be exposed on both outer sides of the valley portion 27, and the effect of both advantages can be achieved.

In the above embodiment, the open portions 37 are formed on both outer sides of the valley portion 27.
An opening may be provided by forming a hole.

The present invention can be applied not only to the cylinder block 1 of a V-type diesel engine but also to a cylinder block of a horizontally opposed engine or an in-line engine, and of course, a gasoline engine.

[0038]

In summary, according to the present invention, even in an engine having no rudder frame, not only the deformation of the cylinder block in the crankshaft direction but also the deformation in the crankshaft orthogonal direction can be suppressed. It has an excellent effect of preventing vibration and noise.

[Brief description of the drawings]

FIG. 1 is a bottom view showing an embodiment of a crankshaft support structure according to the present invention.

FIG. 2 is a longitudinal sectional view of FIG.

FIG. 3 is a plan view of a bearing beam.

FIG. 4 is a bottom view of the bearing beam.

FIG. 5 is a sectional view taken along line AA of FIG. 3;

FIG. 6 is a sectional view taken along line BB of FIG. 3;

[Description of Signs] 1 Cylinder block 5 Skirt part 8 Crankshaft 14 Bearing cap 15 Bearing beam 18 Cap fastening bolt 19 Beam fastening bolt 27 Valley part 28 Mountain part 29 Top part 32 Skirt fastening bolt 33 Skirt connecting part

Claims (3)

[Claims] 1. A crankshaft support structure comprising: a plurality of bearing caps for intermittently supporting a crankshaft from below along an axial direction; and a bearing beam for connecting the bearing caps to each other.
A crankshaft support structure, wherein a skirt connecting portion fastened at a substantially intermediate position between bearing caps of skirt portions on both sides of a cylinder block is formed on the bearing beam. 2. The bearing cap is fastened to the cylinder block by cap fastening bolts, the bearing beam is superimposed on the lower side of the bearing cap and fastened together with the bearing cap by beam fastening bolts, The crankshaft support structure according to claim 1, further comprising an opening for exposing the cap fastening bolt. 3. A crankshaft support structure comprising: a plurality of bearing caps for supporting a crankshaft intermittently from below along an axial direction; and a bearing beam for connecting the bearing caps to each other.
The bearing beam is superimposed on the lower side of the bearing cap and fastened together to the cylinder block by beam fastening bolts, on both sides of the bearing beam,
A ridge that forms a valley at the position of the bearing cap is formed, the bearing beam and the bearing cap are fastened together inside the valley, and the bearing cap is fastened on both outer sides of the valley. Fasten to the cylinder block with bolts for
A crankshaft support structure, which is fastened to a substantially intermediate position between bearing caps of skirt portions on both sides of a cylinder block with skirt fastening bolts.