JPH0561487B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a V-type engine, and more particularly to a balancer installation structure for a V-type engine.

[Prior art]

Generally, in an engine, a crank weight is attached to the crankshaft in order to cancel the vibration caused by the vertical movement of the piston, and in order to cancel the vibration in the direction perpendicular to the crankshaft caused by the rotation of the crank weight. A balancer is installed. Such balancers generally have a balance weight fixed to a balancer shaft installed adjacent to the crankshaft, and the crankshaft and balancer shaft are interconnected by power transmission means such as gears and chains. has been done.

Therefore, engines equipped with balancers had to have longer crankshafts.

[Purpose of the invention]

In view of these problems, the purpose of the present invention is to
An object of the present invention is to provide a V-type engine that is compact in the direction of the crankshaft.

[Structure of the invention]

In the V-type engine according to the present invention, an intermediate shaft parallel to the crankshaft is disposed between the V-shaped cylinders, and the intermediate shaft and the overhead cam shaft of each cylinder are linked between the cylinders. In a V-type engine in which a cam chain is interposed and the rotation of the crankshaft is transmitted to the overhead camshaft via the intermediate shaft, a cam chain is provided on the outer periphery of the movement range of the crank pin on the crankshaft and parallel to the intermediate shaft. , and separate balancer shafts are disposed in such a manner that they sandwich the cam chain therebetween, and these balance shafts and the intermediate shaft are linked to each other via a power transmission means, and a balance weight of the balance shaft is provided. are respectively driven by the power of the intermediate shaft.

〔Example〕

The present invention will be described below with reference to embodiments shown in the drawings.

FIG. 1 is a diagram showing a power transmission mechanism for a V-type engine according to the present invention, and FIG. 2 is a longitudinal cross-sectional view of the main parts thereof. This engine 1 is a DOHC type V-type engine, and includes a forward tilting cylinder 2 and a backward tilting cylinder 3. Also, in this engine 1,
An intermediate shaft 5 is disposed within the V angle formed by the forward-tilting cylinder 2 and the rearward-tilting cylinder 3 and almost directly above the crankshaft 4. The intermediate shaft 5 is arranged parallel to the crankshaft 4 and has approximately the same length as the main part of the crankshaft 4. Sprockets 6 and 7 are fixed to the middle part of the intermediate shaft 5, and a driven gear 8 is fixed to the right end part, and drive gears 9 and 10 are fixed between the sprocket 6 and the driven gear 8 and to the left of the sprocket 7. are arranged respectively. Further, in this engine 1, balance weights 11 and 1 are provided directly above the intermediate shaft 5 and corresponding to the drive gears 9 and 10 of the intermediate shaft 5.
2 are arranged. This balance weight 1
1 and 12 are integrally provided with shafts 11a and 12a, and the shafts 11a and 12a are arranged parallel to the intermediate shaft 5. Driven gears 15 and 16 are disposed on the shafts 11a and 12a via dampers 13 and 14, and the driven gears 15 and 16 mesh with drive gears 9 and 10 of the intermediate shaft 5, respectively. The driven gear 8 of the intermediate shaft 5 is linked to the drive gear 18 of the crankshaft 4 via a belt 17, and the sprockets 6, 7 of the intermediate shaft 5 are linked via cam chains 19, 20.
Sprocket 2 of overhead cam shafts 21 and 22
It is linked with 3 and 24.

The operation of the above engine will be explained below. When the crankshaft 4 is rotated, the drive gear 18 is also rotated accordingly. This drive gear 18
The rotational force is transmitted to the intermediate shaft 5 via the belt 17 and the driven gear 8. When the intermediate shaft 5 is rotated in this manner, the rotational force of the intermediate shaft 5 is applied to the sprocket 6, the cam chain 19, and the sprocket 23.
It is transmitted to the overhead cam shaft 21 via the sprocket 7, the cam chain 20, and the sprocket 24 to the overhead cam shaft 22. On the other hand, the rotational force of the intermediate shaft 5 is transmitted to the balance weight 11 via the drive gear 9 and the driven gear 15, and also to the balance weight 12 via the drive gear 10 and the driven gear 16. Rotate each. At that time, balance weight 11,
12 rotates in the opposite direction to the crankshaft 4 at the same rotational speed as the crankshaft 4, and absorbs vibrations (primary vibrations) caused by the movement of the engine.

In the above embodiment, the intermediate shaft 5 is rotated by a power transmission means using a belt 8, but this power transmission means may be formed by meshing gears with each other.

In addition, in the above embodiment, the balance weight 1
1 and 12 are rotated by a power transmission means consisting of drive gears 9 and 10 and driven gears 15 and 16, but this power transmission means may be one with an additional idler gear or one of other construction such as a belt. But that's fine.

Furthermore, although a four-cylinder engine was shown in the above embodiment, it goes without saying that the present invention can be applied to engines other than four-cylinder engines, and the number of balance weights 11 and 12 is not limited to two.

〔Effect of the invention〕

As described above, the V-type engine according to the present invention utilizes an intermediate shaft that drives the overhead camshaft, and obtains power for the balance weight from this intermediate shaft, so that it can be made more compact in the crankshaft direction. Furthermore, the balance weight can be positioned in a relatively spacious space between the forward-tilting cylinder and the rear-tilting cylinder, which is advantageous in terms of design.

[Brief explanation of the drawing]

FIG. 1 is a conceptual side view showing a power transmission mechanism of a V-type engine according to the present invention, and FIG. 2 is a front view showing a main part of the V-type engine in longitudinal section. 1...V-type engine, 2...forward tilting cylinder, 3
... Rearward tilt cylinder, 4 ... Crankshaft, 5 ... Intermediate shaft, 6, 7 ... Sprocket, 8 ... Driven gear, 9, 10 ... Drive gear, 11, 12 ...
... Balance weight, 11a, 12a ... Axis, 1
3, 14... Damper, 15, 16... Driven gear, 17... Belt, 18... Drive gear, 1
9, 20...cam chain, 21, 22...overhead cam shaft, 23, 24...sprocket.

Claims (1)

[Claims] 1 An intermediate shaft parallel to the crankshaft is disposed between the V-shaped cylinders, and a cam chain is interposed between the cylinders to connect the intermediate shaft and the overhead cam shaft of each cylinder, and the intermediate shaft is parallel to the crankshaft. In a V-type engine in which the rotation of the crankshaft is transmitted to the overhead camshaft via a shaft, the cam chain is arranged parallel to the intermediate shaft and between each other on the outer periphery of the movement range of the crank pin on the crankshaft. Individual balancer shafts are disposed in such a manner that they sandwich the two balance shafts, and these balance shafts and the intermediate shaft are linked to each other via a power transmission means, and the balance weight of the balancer shaft is driven by the power of the intermediate shaft. A V-type engine that is characterized by the fact that it is designed to drive each engine separately.