JP2005195114A - Bearing structure for cylinder block - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing structure for a cylinder block improved in rigidity when connecting a bearing cap to a cylinder head. <P>SOLUTION: The bearing cap 3 is fastened to a spindle wall 2 of the cylinder block 1 by a through bolt 4, and a plurality of fitting grooves 8 and 9 are formed in opposite surfaces 6 of the spindle wall 2 and the bearing cap 3 at positions corresponding to each other, and a plate-like connecting part 10 is pressed into these fitting grooves 8 and 9 for fitting. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a bearing structure of a cylinder block, and more particularly to a structure in which a bearing cap is coupled to a main shaft wall of a cylinder block.

  For example, Patent Document 1 discloses a conventional cylinder block bearing structure. As shown in FIG. 6, the cylinder block 1 is formed with a main shaft wall 2 that partitions the front and rear of each cylinder, and a bearing cap 3 is fitted to the main shaft wall 2 with a collar and fastened with a through bolt 4. Thus, the journal of the crankshaft 5 is configured to be supported by the shaft hole. With such a structure, the bearing cap 3 is firmly coupled to the cylinder block 1.

JP-A-6-50324

  However, when the collars are fitted together, the connection between the main shaft wall 2 and the bearing cap 3 is not sufficient. In particular, in the V-type cylinder block 1 as shown in FIG. Since the load F acts obliquely with respect to the mating surface 6 of the main shaft wall 2 and the bearing cap 3, force acts not only in the direction perpendicular to the mating surface 6 but also in the direction parallel to the mating surface 6. There was a possibility that the bearing cap 3 might slip with respect to 2.

  SUMMARY OF THE INVENTION The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide a cylinder block bearing structure excellent in the rigidity of coupling of a bearing cap to the cylinder block.

The cylinder block bearing structure according to the present invention is a cylinder block bearing structure in which a bearing cap is passed through the main shaft wall of the cylinder block and fastened by bolts, and a fitting groove is formed on each mating surface of the main shaft wall and the bearing cap. This is a structure in which a coupling component is press-fitted into the fitting groove.
A coupling part press-fitted into the fitting groove on the mating surface prevents the bearing cap from sliding against the main shaft wall.
In addition, it is preferable to form the coupling component from a material having higher rigidity than the constituent material of the main shaft wall and the bearing cap.
Also, a connecting part having an E-shaped or T-shaped cross-sectional shape can be used.

  According to this invention, since the coupling component is press-fitted into the fitting grooves formed on the mating surfaces of the main shaft wall and the bearing cap, the coupling rigidity between the cylinder block and the bearing cap is improved. The bearing cap is prevented from slipping even when a force parallel to is applied.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 shows a bearing structure of a cylinder block according to the embodiment. This embodiment is applied to a V-type engine. A main shaft wall 2 for partitioning the front and rear of each cylinder is formed integrally with a cylinder block 1, and a bearing cap 3 is coupled to the main shaft wall 2 to form a crank. A shaft hole 7 through which the journal of the shaft 5 passes is formed. The bearing cap 3 is fastened to the main shaft wall 2 by through bolts 4. A plurality of fitting grooves 8 and 9 are formed on the mating surface 6 of the main shaft wall 2 and the bearing cap 3 at positions corresponding to each other. A flat plate-like coupling component 10 is press-fitted into the mating grooves 8 and 9.

  As shown in FIGS. 2 and 3, the fitting grooves 8 and 9 are formed so as to penetrate through the thickness direction of the main shaft wall 2 and the bearing cap 3, respectively, and the bearing cap 3 abuts on the main shaft wall 2. In this state, the coupling component 10 can be press-fitted in the thickness direction of the main shaft wall 2 and the bearing cap 3.

  Thus, the main shaft wall 2 and the coupling component 10 and the bearing cap 3 and the coupling component 10 are not spaced by press-fitting the coupling component 10 into the fitting grooves 8 and 9 of the main shaft wall 2 and the bearing cap 3. As a result, the coupling rigidity between the main shaft wall 2 and the bearing cap 3, particularly the coupling rigidity in the direction parallel to the mating surface 6 is increased. For this reason, it is possible to prevent the bearing cap 3 from slipping with respect to the main shaft wall 2, wear and seizure of the crankshaft 5 and the bearing, fretting wear of the mating surface 6 of the main shaft wall 2 and the bearing cap 3, loosening of the through bolt 4, etc. Is avoided.

  In particular, in the V-type engine, each cylinder is inclined in a direction determined by the bank angle θ, so that each cylinder is transmitted to the main shaft wall 2 and the cap 3 via the piston 11, the connecting rod 12, and the crankshaft 5 during operation. Although the explosion load has a component parallel to the mating surface 6 of the main shaft wall 2 and the bearing cap 3, since the coupling rigidity in the direction parallel to the mating surface 6 is enhanced by the coupling component 10, the sliding of the bearing cap 3 is effective. Is prevented.

As shown in FIG. 4, fitting grooves 13 and 14 having a T-shaped cross section are formed in the mating surface 6 of the main shaft wall 2 and the bearing cap 3 respectively, and an E-shaped cross section is formed in these fitting grooves 13 and 14. It is also possible to press-fit the coupling component 15 having a shape. With such a structure, the coupling rigidity in the direction perpendicular to the mating surface 6 can be increased.
Similarly, only one of the fitting grooves of the main shaft wall 2 and the bearing cap 3 may have a T-shaped cross section, and a connecting part having a T-shaped cross-sectional shape may be press-fitted and fitted.

Further, as shown in FIG. 5, in the V-type engine, the main spindle wall 20 of the cylinder block 1 and the mating surfaces 18 and 19 that receive the respective explosion loads in the vertical direction corresponding to the respective cylinders 16 and 17. It is also possible to form the bearing cap 21, and to form the fitting grooves 22 and 23 in the mating surfaces 18 and 19 to press-fit the coupling part 10. In this way, a highly rigid joint structure can be obtained both in the vertical direction and in the horizontal direction.
Also in the in-line engine, as shown in FIG. 5, a plurality of mating surfaces having a predetermined angle are formed on the main shaft wall and the bearing cap, and fitting parts are press-fitted by forming fitting grooves on these mating surfaces. Thus, a bonded structure with excellent rigidity can be obtained.

In addition, by forming the coupling parts 10 and 15 from a material having higher rigidity than the constituent materials of the main shaft walls 2 and 20 and the bearing caps 3 and 21, the coupling rigidity between the main shaft walls 2 and 20 and the bearing caps 3 and 21 is increased. It can be further increased.
Further, the shapes, the number, and the arrangement positions of the fitting grooves 8, 9, 22, and 23 and the coupling parts 10 and 15 are appropriately determined according to the magnitude of the cylinder explosion load, the structure of the bearing caps 3 and 21, and the like.
Note that the rigidity of the coupling between the main shaft wall and the bearing cap can also be increased by increasing the axial force of the through bolt for fastening the bearing cap to the main shaft wall or increasing the number of through bolts. There is a possibility that the stress of each part of the main shaft wall and the bearing cap is increased and the strength is lowered. In the present invention, since the coupling component is press-fitted into the fitting groove formed in the mating surface, the coupling rigidity between the main shaft wall and the bearing cap can be improved without the above-described decrease in strength. Become.
The present invention is effective not only in a V-type engine but also in an in-line engine, and a bearing cap can be firmly coupled to a cylinder block.

It is sectional drawing which shows the bearing structure of the cylinder block which concerns on embodiment of this invention. It is a top view which shows the mating surface of a main shaft wall. It is a top view which shows the mating surface of a bearing cap. It is sectional drawing which shows the coupling component used in other embodiment. It is sectional drawing which shows the bearing structure of the cylinder block which concerns on other embodiment. It is sectional drawing which shows the bearing structure of the conventional cylinder block.

Explanation of symbols

  1 Cylinder block, 2,20 Main shaft wall, 3,21 Bearing cap, 4 Through bolt, 5 Crankshaft, 6, 18, 19 Mating surface, 7 Shaft hole, 8, 9, 13, 14, 22, 23 Mating groove 10, 15 Connecting parts, 11 pistons, 12 connecting rods, 16, 17 cylinders.

Claims (3)

In the cylinder block bearing structure in which a bearing cap is passed through the spindle wall of the cylinder block and fastened with bolts,
A mating groove is formed on the mating surface of the spindle wall and bearing cap,
Cylinder block bearing structure characterized by press fitting fitting parts into these fitting grooves.   The cylinder block bearing structure according to claim 1, wherein the coupling part is formed of a material having higher rigidity than a constituent material of the main shaft wall and the bearing cap.   The bearing structure for a cylinder block according to claim 1 or 2, wherein the coupling part has an E-shaped or T-shaped cross-sectional shape.

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