JPH10267085A - Primary balancer device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress noise of an engine to the minimum, by integrally arranging a balance weight coaxially with a driven gear which is reversely rotated at the same speed as a crankshaft and drives an auxiliary machine. SOLUTION: A balance weight 5 is integrally arranged coaxially with an idle shaft 3 to which an idle gear 4 meshed with the crank gear 2 of a crankshaft 1 is fixed thereby, this balance weight 5 can function as a primary balancer. Here, this idle gear 4 is so arranged that it drives an adjacent cam gear 6 while being reversely rotated at the same speed as the crankshaft 1. Then, respective auxiliary machines require different rotational speeds therefore, the balance weight 5 is arranged on the idle gear 4 which can freely adjust rotational speeds and rotational directions. Hereby, additional gears can be suppressed to the minimum extent, and increase of weight can be suppressed to the utmost, and also increase of the meshing parts of the gears is few therefore, deterioration of noises can be suppressed to the utmost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a primary balancer for an internal combustion engine mainly applied to a V-type internal combustion engine having cylinders arranged in a V-shape.

[0002]

2. Description of the Related Art Conventionally, in the case of a V-type internal combustion engine, a bank angle of 9
If the angle is other than 0 degrees, or if an offset is provided to the crankpin of the crankshaft, the primary rotational couple remains in the same rotation direction and the opposite rotation direction of the crankshaft at the same rotation speed as the crankshaft. The above couple in the same rotational direction can easily be made zero by providing a counterweight on the crankshaft, while the couple in the reverse rotational direction is newly added to the crankshaft in the opposite direction to the crankshaft. A balancer that rotates at the same rotational speed as the shaft is required. Therefore, if this condition is neglected, a primary vibrating force is generated from the internal combustion engine, and the vehicle equipped with the internal combustion engine is vibrated, and the riding comfort is greatly deteriorated.

Therefore, conventionally, in order to reduce the primary couple to zero, a new gear train is provided before and after the internal combustion engine.
It has been performed to add a balancer that rotates in reverse at the same rotation speed as the crankshaft, or to add a balancer shaft that penetrates the internal combustion engine. For example, as a conventional example of the above countermeasure, there is a motorcycle in which a balancer is rotatably mounted in front of a crankshaft, and the crankshaft and the balancer are connected via a gear at one end or both ends on either left or right. Many proposals have been made in addition to the invention of JP-A-59-65643 relating to a balancer for a vehicle engine.

However, it is not preferable to newly provide a balancer with a gear as described above, because it causes an increase in weight and an increase in the number of meshing portions of the gears, thereby deteriorating noise. Also, providing a balancer shaft extending through the front and rear of the internal combustion engine is not preferable because the rigidity of the cylinder block and weight increase are expected.

[0005]

SUMMARY OF THE INVENTION In order to reduce the primary couple in an internal combustion engine to zero, the present invention suppresses the increase in gravity by minimizing the addition of gears when mounting a primary balancer, and reduces the engagement of gears. Provided is a primary balancer device of an internal combustion engine that can reduce increase and reduce noise of the engine as much as possible.

[0006]

According to the present invention, there is provided a gear train provided at an end in a longitudinal direction of an internal combustion engine, which is an idle gear that rotates in reverse at the same speed as a crankshaft and drives an adjacent gear. This is a primary balancer device of an internal combustion engine in which a balance weight is provided integrally on a coaxial structure. Further, the primary balancer device of the present invention is configured such that, among the gear trains provided at the longitudinal end of the internal combustion engine, the gear train rotates in the reverse direction at the same speed as the crankshaft and is coaxial with the driven gear driving the auxiliary machine. , And a balance weight are provided in an integral structure.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A primary balancer device according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a front view of a main part of a gear train of the embodiment, and FIG. It is an expanded side sectional view of the arrow AA direction. First, among the gear trains shown in FIGS. 1 and 2 provided at the front or rear end in the longitudinal direction of this internal combustion engine, for example, a V-type internal combustion engine, an idle gear 4 meshing with the crank gear 2 of the crankshaft 1 Idle shaft 3 with fixed
By providing the balance weight 5 on the same axis as the integral structure, the balancer weight 5 functions as a primary balancer.

The idle gear 4 drives the adjacent cam gear 6 while rotating in reverse at the same speed as the crankshaft 1. The cam gear 6 further drives the gear 7 of the fuel injection pump, and then drives the gear 8 of the air compressor. A gear train is usually provided at the longitudinal end of the internal combustion engine. There are two types of gears provided on this gear train, and one of them is an auxiliary machine of the internal combustion machine, For example, it is a driven gear for driving a fuel injection pump, an air compressor, an oil pump, a generator, and the like with the crankshaft 1. The other is an idle gear 4 for adjusting the rotation direction and the rotation speed of the auxiliary machine as described above.

Therefore, in the present invention, in order to function as a primary balancer of the internal combustion engine, it is necessary that the crankshaft 1 rotates in the reverse direction and has the same rotational speed. Each of the above-mentioned auxiliary machines has a necessary rotation speed, and since these speeds are different from each other, the rotation speed and the rotation direction can be freely adjusted as in this embodiment shown in FIGS. It is preferable to provide a balance weight 5 on the idle gear 4.

The idle shaft 3 is formed in the shape of a hollow cylinder as shown in FIG. 2. A small idle gear 3a is provided in the center of the idle shaft 3, and an idle gear 4 is provided by shrink fitting or press-fitting on one of the idle shafts 3 and the other is provided on the other side by the same method as shown in FIG. The balance weight 5 formed in an arc shape shown in FIG. 1 is fixed by shrink fitting or press fitting. The method of fixing the balance weight 5 to the idle shaft 3 may be another method.

However, the provision of the balance weight 5 in an integral structure on the same axis as the driven gear for driving the accessory as described above requires that the rotation speed of the balance weight 5 be the same as that of the crankshaft 1 and that the rotation speed be in the reverse rotation direction. Any driven gear can be used, and in this case, the same functions and effects as those of the embodiment of FIG. 1 can be provided. The present invention is effective mainly as a primary couple balancer device of the V-type internal combustion engine described above. However, the present invention is applicable to a primary or secondary engine of an L-type (serial) or H-type (horizontally opposed) internal combustion engine or the like. The present invention can also be effectively applied as a balancer of the following inertial force or couple.

[0012]

According to the primary balancer device of the internal combustion engine of the present invention described above, the addition of gears is minimized, the increase in weight is suppressed as much as possible, and the increase in the meshing portion of the gears is small, so that the noise is reduced. It is possible to provide a primary balancer that minimizes deterioration. As a result, it is possible to improve the riding comfort of a vehicle equipped with an internal combustion engine to which the present invention is applied.

[Brief description of the drawings]

FIG. 1 is a front view of a main part of a gear train according to an embodiment to which a primary balancer device of an internal combustion engine of the present invention is applied.

FIG. 2 is a development side sectional view of the gear train of FIG. 1 in the direction of arrows AA.

[Explanation of symbols]

 1 crankshaft 4 idle gear 5 balancer weight

Claims (2)

[Claims] 1. A gear train provided at a longitudinal end of an internal combustion engine, reversely rotates at the same speed as a crankshaft,
And on the same axis of the idle gear that drives the adjacent gear,
Primary balancer for internal combustion engine with integrated balance weight. 2. A gear train provided at an end in a longitudinal direction of the internal combustion engine, reversely rotates at the same speed as a crankshaft,
A primary balancer device for an internal combustion engine in which a balance weight is provided integrally with a driven gear that drives an auxiliary machine.