JPS63272952A - Reinforcement member construction for cylinder block - Google Patents

Abstract

PURPOSE:To enhance rigidity by specifying the fitting position of divisions on a reinforcement member and the connection height thereof in the construction wherein the reinforcement member of approximately chute form monolithic with a plurality of divisions is provided at the lower part of a skirt part adjacent to a cylinder block. CONSTITUTION:A skirt part 10 comprising a pair of right and left skirts is formed at the lower part of a cylinder block 1 and an oil pan 2 is tightened to an oil pan rail 18 formed at the lower end of the skirt part 10. And a reinforcement member 3 comprising a reinforcement member proper 31 and a plurality of divisions 32 and so on is so laid as to cover a space below the skirt part 10. The reinforcement member proper 31 is comprised of a pair of right and left flange parts 36 and a bottom plate 37 of nearly chute form bulged below an engine. In this case, the reinforcement member 3 is kept approximately at the same height as the flange parts 36 in respect of the upper end of the connection of the bottom plate 37 and the divisions 32. The height (h) of the connection part is so set as to be within 1/6-1/2 of the height H of the reinforcement member 31.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a reinforcing member structure for a cylinder block.

(Prior Art) Generally, the lower ends of the skirt portions of cylinder blocks are spaced apart from each other, so their bending rigidity and torsional rigidity in the lateral direction are weaker than other parts.
There is a problem in that the lower end of the skirt vibrates during engine operation, leading to an increase in engine noise.

In order to solve this problem, for example,
As disclosed in Japanese Patent No. 6, the lower ends of a pair of left and right skirts facing each other at a distance are connected by a reinforcing member to increase the bending rigidity and torsional rigidity of the lower ends of the skirts, and thus of the cylinder block. It is proposed to do so.

By the way, as shown in FIG. 7 or 8, this reinforcing member usually has a pair of left and right flange portions 53, 53 and approximately V
A reinforcing member main body 5I consisting of a bottom plate portion 52 having a letter-shaped cross section.
and a partition wall 54 provided on the bottom plate portion 52 of the reinforcing member main body 51, and the partition wall 54 has a triangular plate shape that covers the entire area of the bottom plate portion 52 as shown in FIG. Alternatively, as shown in FIG.
It was common to have a band-like structure that covered only a portion of the area.

However, in the case of conventional reinforcing members, the strength of the partition wall 54 has not been sufficiently analyzed, and therefore, for example, in the structure shown in FIG. 7, although sufficient rigidity is ensured, the weight increases. There are concerns that problems may occur, such as hindering the reduction in weight of the engine, or in the case of the structure shown in FIG. 8, although it is lightweight, sufficient rigidity cannot be ensured.

(Object of the Invention) The present invention is intended to solve the problems pointed out in the above-mentioned section of the prior art. The purpose of this invention is to propose a cylinder block reinforcing member structure that can achieve both improved rigidity (dynamic rigidity) and reduced weight of the reinforcing member.

(Technical Background of the Invention) In order to obtain a reinforcing member that maintains both the bending rigidity and torsional rigidity of the cylinder block well and is as lightweight as possible, a greater effect of increasing rigidity can be obtained by making the partition wall as small as possible. Therefore, the inventors of the present invention installed reinforcing members with partition walls of various shapes on the cylinder block and analyzed their vibrations. We have now discovered the most suitable shape and dimensions for the partition wall in terms of both the rigidity and weight reduction of the cylinder block.

That is, as shown in FIG. 7, a basic reinforcing member is constructed in which a triangular partition wall 54 is attached to a reinforcing member main body 51 having a shaped cross-sectional shape so as to cover the entire area of the bottom plate portion 52 of the reinforcing member main body 51. It is assumed that the height of the partition wall 54 is the same as the maximum depth H of the reinforcing member body 51. Then, as shown in FIG. 5, when each reinforcing member constructed by sequentially removing the partition wall 54 of the basic reinforcing member from the lower side and gradually reducing its height is attached to the cylinder block. (first form), and each reinforcing member constructed by sequentially removing the partition wall 54 from the upper side and gradually reducing its height dimension, contrary to the first form as shown in FIG. The changes in the lateral bending stiffness and torsional stiffness of the cylinder block itself were investigated by computer-based vibration analysis using an FEM (finite element method) model when each of the cylinder blocks was mounted on the cylinder block (second form). . The results are shown in FIG.

Note that the higher the natural frequency of the cylinder block, the better the lateral bending rigidity and torsional rigidity of the cylinder block.

Further, in FIG. 4, the state of change in stiffness in the first form is shown by a solid curve, and the state of change in stiffness in the second form is shown by a broken curve.

As a result of considering Fig. 4, first, when comparing the first form and the second form, the first form has significantly higher lateral bending rigidity and torsional rigidity than the second form. It turns out that it is excellent.

Furthermore, in this first form as well, the partition wall height h is 1
/ If the height h of the partition wall is less than 68, the effect of installing the partition wall will be greatly impaired and the installation of the partition wall itself will be meaningless, and if the height h of the partition wall is 1/2H or more, the height of the partition wall will be increased. Therefore, no further increase in rigidity can be expected, and only the weight will increase.

Based on these facts, the height of the partition wall that can be made as light as possible and achieve the maximum effect of increasing rigidity is 1/6H-
It can be said that the range is 1/2H.

(Means for Achieving the Object) As a means for achieving the above object, the present invention provides a method for attaching the lower end portions of a pair of left and right skirts located at the lower part of the cylinder block to the lower surface of the lower end portions of the pair of skirts. a reinforcing member main body consisting of a pair of left and right flange portions serving as a section and a substantially gutter-shaped bottom plate portion that bulges out toward the lower side of the engine in continuation with the pair of flange portions; In an engine cylinder block interconnected by a reinforcing member consisting of a plurality of partition walls arranged at positions corresponding to each crank bearing of the block and having both ends joined to the bottom plate portion of the reinforcing member, The reinforcing member has an upper end position of a joint between the bottom plate portion of the reinforcing member main body and the partition wall at approximately the same height as the flange portion of the reinforcing member main body,
The height dimension from the upper end to the lower end of the joint part is measured by passing through the intersection of the pair of left and right flanges of the reinforcing member main body and the bottom plate part and the corner part on the bottom plate side located between the two intersections. Moreover, the inner circumferential surface of the reinforcing member main body is set within the range of 1/6 to 1/2 of the height from the lowest end position on the circumference of the arc located inside the reinforcing member main body to the upper surface of the flange portion. be.

(Function) In the present invention, the rigidity of the reinforcing member as a whole is effectively improved by the above means, so that the vibration deformation of the skirt portion of the cylinder block is suppressed as much as possible, and the lateral direction of the cylinder block as a whole is improved. Bending stiffness and torsional stiffness will be improved.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described with reference to FIGS. 1 to 3.

1 and 2 show the lower part of an automobile engine equipped with a reinforcing member structure according to an embodiment of the present invention, and in each figure, reference numeral I is a cylinder block, 2 is an oil pan, and 3 is a This is a reinforcing member that forms the main subject of the present invention and will be described in detail later.

A skirt portion 10 is formed in the lower part of the cylinder block I. The skirt portion 10 includes a pair of left and right scars 11 and 12 facing each other with the crank bearing 15 and the bearing cap 16 interposed in the axial direction. Each skirt 11.1 of this oil pan 2
The oil pan 2 is fastened and fixed to an oil pan rail 18.18 formed at the lower end of the oil pan 2. Furthermore, reinforcing member mounting bosses 13, 13, for fastening and fixing reinforcing members 3, which will be described later, are integrally formed inside the left and right oil pan rails 18, 18 of the cylinder block 1, respectively.

As shown in FIGS. 1 to 3, the reinforcing member 3 is disposed astride between the left and right skirts II and 12 so as to cover the lower part of the skirt portion IO of the oil pan 2. It has a main body 31 and a plurality of (five in this embodiment) partition walls 32, 32, . . . .

The reinforcing member main body 31 is formed by bending a steel plate having a size that can cover the lower part of the skirt portion 10 of the oil pan 2, and has side edges corresponding to both sides of the oil pan 2. A pair of left and right flange portions 36.36 extend in the cylinder arrangement direction of the cylinder block l, and a pair of left and right side walls 33.36 continue inside each of the flange portions 36.36 and slope downward inward. 34, and the side wall 33.
34 and has a bottom wall 35 extending parallel to each of the flange portions 36, 36. This side wall 33.3
4 and the bottom wall constitute the bottom plate portion 37 in the claims.

The partition wall 32 is a beam having a mouth-shaped cross section and a length dimension approximately corresponding to the horizontal distance between the intersection point P IMP of each flange portion 36.36 of the reinforcing member main body 31 and the side wall 33.34. portion 38, and joining flanges 39, 39 located at both ends of the beam portion 38 and capable of abutting against the side walls 33, 34 of the reinforcing member main body 3I, respectively. The partition wall 32 is arranged between left and right side walls 33, 34 of the reinforcing member main body 31 at positions corresponding to the crank bearings 15, 15, etc. on the cylinder block side in the crankshaft direction. The reinforcing member main body 31 is integrated with the reinforcing member main body 31 by joining the joint flanges 39 and 39 to the respective side walls 33 and 34 by spot welding. Together with this, the reinforcing member 3 is configured.

The reinforcing member 3 configured in this way has a flange portion 3
6.36 are fixed to the cylinder block l side by bolting them to the left and right reinforcing member mounting bosses 13, 13, etc. of the cylinder block l from their lower surfaces, thereby preventing vibration deformation of the skirt portion 10 of the cylinder block l. This acts to suppress the lateral bending rigidity and torsional rigidity of the cylinder block l.

By the way, in this case, as described above, the beam portion 38 of the reinforcing member 3
There exists a size and shape that can both improve the lateral bending rigidity and torsional rigidity of the cylinder block I and reduce the weight of the reinforcing member 3 itself. Therefore, in this embodiment, the present invention is applied to the partition wall 32 and the side wall 3 of the reinforcing member main body 31.
3. Height dimension of joint with 34 and reinforcing member main body 3
The mounting position in the height direction with respect to 1 is set as follows.

That is, as shown in FIG. 1, the upper end positions of both joining flanges 39.39 of the partition wall 32 are located at the intersections PL and P2 of the flange portion 36.36 of the reinforcing member main body 31 and the side wall 33.34.
as close as possible, and the height dimension h(
That is, the vertical dimension between the upper end and the lower end of the joint flange 39 of the partition wall 32) is defined as the intersection point P, , P of the flange portion 36.36 of the reinforcing member main body 31 and the side wall 33.34, and the side wall 34.34. 34 and the bottom wall 35 (corresponding to the corner portion in the scope of claims) P 3 + P 4 The highest point on the arc within which the reinforcing member main body 31 is located The distance H between the lower end point P and the upper surface of the flange portion 36 in the vertical direction is set within a range of 1/6 to 1/2. That is,
As explained in the "Technical Background of the Invention" section above, assuming that the form of the partition wall 32 is the first form, the height of the partition wall can be adjusted to improve the lateral bending stiffness and torsional stiffness of the cylinder block. The dimensions are set to be the most advantageous. For this reason, the cylinder block is strengthened by the reinforcing member 3! The lateral bending stiffness and torsional stiffness of the reinforcing member 3 are maintained at the highest level, and the weight of the reinforcing member 3 is reduced as much as possible.

In addition, in this embodiment, the reinforcing member main body 3 of the reinforcing member 3
Both ends of the reinforcing member main body 31 are cut off to form end faces, but in other embodiments of the present invention, ribs 41 are provided at both ends of the reinforcing member main body 31 as shown by chain lines (reference numeral 41) in FIGS. 1 and 2, respectively. Good too. In this case, deformation of the flange portion 36 of the reinforcing member main body 31 can be suppressed, which is even more advantageous in terms of increasing the rigidity of the reinforcing member 3 as a whole.

Further, as shown by reference numeral 42 in FIG. 1 (shown by chain lines), if the axially intermediate portion of the partition wall 32 and the bottom wall 35 of the reinforcing member main body 3I are connected by the legs 42, the bottom wall 35 and the partition Since the deformation of the beam portion 38 of the wall 32 is suppressed, the reinforcing member 3
This is advantageous in terms of increased rigidity.

(Effects of the Invention) The present invention connects the pair of left and right skirt lower end portions located at the lower part of the cylinder block to the left and right flange portions that are the attachment portions to the lower surface of the pair of skirt lower end portions and the pair of left and right flange portions. a reinforcing member main body consisting of a substantially gutter-shaped bottom plate portion that bulges out toward the lower side of the engine continuously; the reinforcing member body is arranged at a position corresponding to each crank bearing of the cylinder block in the crankshaft direction of the main body; In an engine cylinder block interconnected by a reinforcing member comprising a plurality of partition walls whose both ends are joined to the bottom plate portion of the reinforcing member body, the reinforcing member is connected to the bottom plate portion of the reinforcing member main body. The upper end position of the joint with the partition wall is set to be approximately the same height as the flange of the reinforcing member main body, and the height dimension from the upper end to the lower end of the joint is set between the left and right sides of the reinforcing member main body. from the lowermost position on the circumference of an arc that passes through the corner part on the bottom plate side located between the intersection of the flange part and the bottom plate part, and in which the inner circumferential surface of the reinforcing member main body is located inside. It is characterized in that the height is set within a range of 1/6 to 1/2 of the height to the top surface of the flange portion.

Therefore, according to the cylinder block reinforcing member structure of the present invention, the shape and dimensions of the partition wall of the reinforcing member are set so that it functions most effectively in suppressing lateral bending and twisting of the cylinder block, and is as small as possible. Therefore, it is possible to promote weight reduction of the reinforcing member while maintaining sufficient lateral bending rigidity and torsional rigidity of the cylinder block.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view of a main part of a cylinder block equipped with a reinforcing member having a reinforcing member structure according to an embodiment of the present invention, Fig. 2 is a longitudinal cross-sectional view of main parts along ■ - ■ of Fig. 1, and Fig. 3 is III- in Figure 1
I FIG. 8 is a longitudinal sectional view showing an example of the structure of a conventional reinforcing member. l...Cylinder lock 2...Oil pan 3...Reinforcement member lO...Skirt portion 11.12...Skirt 13...Reinforcement member mounting boss 15... ... Crank bearing 31 ... Reinforcement member main body 32 ... Partition wall 33, 34 ... Side wall 35 ... Bottom wall 36 ... Flange section 37 ... Bottom plate section 38 ... ...Beam section 39...Joining flange-I-' 1 Niji cylinder block 2 Niji oil pan: Reinforcement member IO = skirt portion //, /2 Niji skirt 31: 9 section 39: Joining flange Fig. 8

Claims (1)

[Claims] 1. The lower ends of the left and right skirts located at the bottom of the cylinder block are connected to the pair of left and right flanges that are the attachment points to the lower surface of the lower ends of the skirts, and the lower end of the engine is connected to the pair of flanges. a reinforcing member main body consisting of a substantially gutter-shaped bottom plate portion that bulges out; In an engine cylinder block interconnected by a reinforcing member consisting of a plurality of partition walls joined to the bottom plate, the reinforcing member connects the bottom plate of the reinforcing member main body to the partition wall. The upper end position of the part is approximately the same height as the flange part of the reinforcing member main body, and the height dimension from the upper end to the lower end of the joint part is
It passes through the intersection of the pair of left and right flanges of the reinforcing member main body and the bottom plate part and the corner part on the bottom plate side located between the two intersections, and the inner circumferential surface of the reinforcing member main body is A reinforcing member structure for a cylinder block, characterized in that the height is set within a range of 1/6 to 1/2 of the height from the lowest end position on the circumference of the circular arc to the upper surface of the flange portion.