JPS6175085A - Suspension structure of engine for car - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a suspension structure for a vehicle engine, and particularly to a suspension structure suitable for a motorcycle engine.

[Prior art]

Generally, in a vehicle engine, the crankcase is divided into upper and lower parts with the crankshaft in between, and the upper crankcase and the lower crankcase are integrally tightened and fixed with tightening bolts.

As described above, a suspension boss is provided protruding from the outside of the rank case, and the engine is suspended by attaching this 1U suspension boss to the vehicle body frame via suspension bolts. This L rack boss is subject to extremely high stress, so in the case of engines mounted on motorcycles, etc.
Usually, the U-frame boss is provided in a part with high slippage, such as the front part corresponding to the bearing part of the crankshaft.

Furthermore, in order to prevent oil leakage, it is desirable that the tightening bolts of the upper and lower crankcases be tightened at portions corresponding to the bearing portions of the crankshaft, which have high rigidity. However, if a suspension boss is provided in the part corresponding to the bearing as described above, the suspension bolt that is pushed through this single suspension boss will interfere with the tightening bolt, so In an engine, one of them has to be provided in a part other than the part corresponding to the bearing part. Therefore, in order to prevent oil leakage due to lack of rigidity in that part or crank occurrence at the suspension boss, the wall thickness has been increased, resulting in an increase in weight.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an engine suspension structure in which a suspension boss and an insertion hole for a case tightening bolt can be provided at the same time in a portion corresponding to a crankshaft bearing.

[Structure of the invention]

To achieve the above object, the present invention provides a vehicle engine in which the crankcase is divided into an upper crankcase and a lower crankcase with a crankshaft in between, in which a front portion of the lower crankcase corresponds to one crankshaft bearing portion. A suspension boss is formed in the suspension boss, and a bolt insertion hole for a suspension bolt is provided horizontally in this suspension boss, and the crankcase is connected to the upper crankcase side through a space formed across the bolt insertion hole. It is characterized by having a bolt insertion hole for a tightening bolt.

[Embodiments of the invention]

Hereinafter, the present invention will be explained with reference to embodiments shown in the drawings.

In the motorcycle shown in Fig. 5, l is the body frame;
2 is a four-cylinder engine mounted on this body frame 1, and has a suspension structure as described below.

As shown in FIGS. 1 to 4, the crankcase of the engine 2 is composed of an upper crankcase 3a and a lower crankcase 3b, and between the two crankcases 3a and 3b, each is integrally formed. A crankshaft 5 is supported via bearings 4a and 4b. A cylinder block 6 is integrally fastened to the upper part of the upper crankcase 3a via a stand port 7. This cylinder block 6 is provided with four cylinders (not shown) in series in the lateral direction, and the two cylinders on both sides communicate with each other via a notch space 8 at the base of the upper crankcase 3a. are doing. This cutout space 8 reduces horsepower loss due to the pumping action of the piston in each cylinder.

The upper crankcase 3a and the lower crankcase 3b are tightened and fixed by a plurality of tightening ports 9 along their base surfaces. In addition, in the bearing parts 4a and 4b, the tightening poles 1-10.
It is tightened and fixed. Furthermore, in the portion of the notch space 8 that communicates between the cylinders, the bearing portion 4a,
They are integrally tightened and fixed by a tightening port 11 at a position outside the tightening port 10 of 4b and inside of the tightening port 9 on the crankcase base. This tightening pole l-11 is simply used for the upper and lower crankcases 3a, 3
In addition to the tightening part b, the notch space 8 also serves as a tightening part to compensate for the reduced rigidity of the bearing parts 4a and 4b.

A suspension boss 12 is integrally formed in a front portion of the lower crankcase 3b corresponding to the bearing portion 4b. A bolt insertion hole 14 for inserting a suspension bolt 13 passes through the suspension boss 12 in the lateral direction. The front end of the engine 2 is suspended by being attached to the bracket 1a of the vehicle body frame 1 via a suspension bolt 13 inserted into a bolt insertion hole 14 of the suspension boss 12. 17
is a suspension boss on the upper crankcase 3a side, and is attached to the bracket 1b of the vehicle body frame 1 in the same manner as the suspension boss 12 described above.

Further, the suspension boss 12 is formed with a space 15 that extends across the bolt insertion hole 14 and is open at the bottom and has a bottom surface at the top. A bolt insertion hole 1 is inserted upward from the bottom of the space 15 toward the upper crankcase 3a.
6 is provided. The above-mentioned tightening bolts 9 for tightening the base surfaces of the upper and lower crankcases 3a, 3b are stored in the bolt insertion holes 16, and both cases are tightened and fixed.

According to the above-mentioned engine suspension structure, the suspension boss 12 is provided at a front side portion with high rigidity corresponding to the bearing portion 4b of the crankshaft 5, so that the structure is such that cracks and the like are less likely to occur.

In addition, since the suspension boss 12 is provided with a space 15 that crosses the boss insertion hole 14 of the suspension boss 13,
It is possible to provide bolt insertion holes 16 for the tightening bolts 9 on the upper and lower crankcase base surfaces. Therefore, since the tightening bolt 9 tightens and fixes the upper and lower crankcases 3a, 3b in the front portion corresponding to the highly rigid bearing portion 4b, the tightening bolt 9 can be tightened and fixed without particularly thickening other parts. It is possible to eliminate oil leakage from the table surface.

In the above-mentioned embodiment, a case where a motorcycle engine is suspended is explained, but the present invention can also be applied to an eight-frame suspension of other vehicle engines having a similar configuration.

〔Effect of the invention〕

As described above, the present invention provides a vehicle engine in which the crankcase is divided into an upper crankcase and a lower crankcase with a crankshaft in between. A boss is formed, and a bolt insertion hole for a suspension bolt is installed horizontally in this suspension boss, and a space for tightening the crankcase that passes through the snow to the upper crankcase side through a space formed across this bolt insertion hole. Since the bolt insertion holes are provided, the ', ε frame bosses and the case tightening bolt insertion holes can be provided at the same time in the highly rigid part corresponding to the crankshaft bearing. Therefore, it is possible to obtain a robust engine suspension mechanism that does not cause cracks in the suspension boss or oil leakage without causing an increase in weight due to extra wall thickness.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing the main parts of a motorcycle engine having an engine suspension structure according to the present invention, FIG. 2 is a view taken along the ■-■ arrow in FIG. FIG. 4 is a top view of the crankcase, FIG. 4 is a bottom view of the crankcase, and FIG. 5 is a side view of the motorcycle equipped with the same engine. ■...Vehicle frame, 1a...Bracket, 2
...Engine, 3a...Upper crankcase, 3
b...lower crankcase, 4a, 4b...bearing portion, 5...crankshaft, 9...tightening bolt (of upper and lower crankcases), 12...suspension boss,
13... is a mounting bolt, 14.16... is a bolt insertion hole, 15... is a space.

Claims (1)

[Claims] In a vehicle engine in which the crankcase is divided into an upper crankcase and a lower crankcase with the crankshaft in between, a suspension boss is formed at the front portion of the lower crankcase corresponding to the crankshaft bearing portion, and the suspension boss is attached to the suspension boss. The bolt insertion hole for the suspension bolt is provided horizontally, and the bolt insertion hole for the crankcase tightening bolt is provided to penetrate to the upper crankcase side through a space formed across this bolt insertion hole. Characteristic engine suspension structure.