JP2010059906A - Balancer device of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To lubricate gears for driving a Heron balancer by a simple structure, in regard to the balancer device of an internal combustion engine. <P>SOLUTION: This balancer device 10 of an internal combustion engine comprises the Heron balancer 18 rotating in the opposite direction of a crankshaft 12. The Heron balancer 18 is driven by the crankshaft 12 via the gears 22, 20. A plurality of oil splashing holes 40 are formed in the Heron balancer 18. Each oil splashing hole 40 are opened in the Heron balancer 18 through the outer peripheral surface and the gear 20 side side-surface thereof. When the Heron balancer 18 is rotated, the outer peripheral openings of the oil splashing holes 40 are dipped sequentially in the oil contained in an oil pan. Consequently, the oil flows energetically into the oil splashing holes 40 from the outer peripheral openings and flows energetically out of the side-surface, and adheres to the gear 20. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a balancer device for an internal combustion engine.

  In single-cylinder engines and two-cylinder engines, since the explosion interval becomes long, torque fluctuations and engine rolling vibration tend to be problems. In order to suppress this torque fluctuation and rolling vibration, a technique of providing a heron balancer (sub flywheel) that rotates in the opposite direction to the crankshaft is known. In order to sufficiently obtain the effect of the heron balancer, it is preferable that the mass (inertia) of the heron balancer is large, but an increase in weight becomes a problem. Therefore, by rotating the heron balancer at a speed faster than that of the crankshaft, the apparent inertia increases, and the same effect as that of the heavy heron balancer can be obtained.

JP 2001-263024 A JP 2002-349222 A JP-A-5-71585

  The balancers of the internal combustion engine, including the heron balancer, are usually driven by a crankshaft via a gear. These gears are arranged so as to be slightly immersed in the oil in the oil pan, and are configured to be naturally lubricated.

  However, in order to increase the speed of the heron balancer relative to the crankshaft, it is necessary to make the gear provided on the heron balancer smaller in diameter than the gear provided on the crankshaft. If it does so, the gear provided in the heron balancer will become small and will not reach the oil level in an oil pan. That is, the gear provided in the heron balancer is not immersed in the oil in the oil pan. Therefore, in order to lubricate the gear, it is necessary to additionally provide a lubricating device such as an oil jet, which increases the cost.

  Japanese Patent Laid-Open No. 2001-263024 discloses an apparatus for lubricating a spline fitting portion that connects a hydraulic power take-out shaft of an engine and a hydraulic pump. In this apparatus, a refracting oil hole is provided in the hydraulic power take-out shaft, and lubricating oil in the gear case is supplied to the spline fitting portion through the refracting oil hole. With this technique, splines inside the shaft can be lubricated, but gears outside the shaft cannot be lubricated.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a balancer device for an internal combustion engine that can lubricate a gear for driving a heron balancer with a simple structure.

In order to achieve the above object, a first invention is a balancer device for an internal combustion engine,
A heron balancer partly immersed in the oil in the oil pan,
A gear that rotates integrally with the heron balancer and is not immersed in the oil in the oil pan;
With
The heron balancer is formed with a plurality of oil blow-off holes formed in a direction from the outer periphery to the gear, and when the heron balancer rotates, the gear is caused by oil that has jumped out of the oil blow-off holes. It is characterized by being lubricated.

  According to the first invention, when the heron balancer, which is partially immersed in the oil in the oil pan, rotates, the oil is ejected from the oil blowout hole formed in the heron balancer. And the gear for driving a heron balancer can be lubricated with the oil which jumped out. For this reason, even if the gear is not immersed in oil, it is not necessary to provide a separate lubricating device such as an oil jet. Therefore, the structure can be simplified and the cost can be reduced.

Embodiment 1 FIG.
FIG. 1 is a diagram schematically illustrating a balancer device according to a first embodiment of the present invention. A balancer device 10 according to this embodiment shown in FIG. 1 is applied to an in-line two-cylinder internal combustion engine. A crankshaft 12 of this internal combustion engine (hereinafter simply referred to as “engine”) is provided with crankpins 14 and 16 corresponding to two cylinders. The crank pins 14 and 16 are provided in the same phase. Although not shown, two cylinders are provided above the crankshaft 12. Pistons inserted into these cylinders are connected to crankpins 14 and 16 via connecting rods, respectively.

  The balancer device 10 includes a heron balancer 18 that rotates about an axis parallel to the crankshaft 12. The heron balancer 18 has a disk shape. The heron balancer 18 is provided with a gear 20 coaxially. The heron balancer 18 and the gear 20 rotate together.

  The crankshaft 12 is provided with a gear 22. The crankshaft 12 and the gear 22 rotate together. The gear 20 and the gear 22 are engaged with each other. When the crankshaft 12 rotates, the rotation is transmitted to the heron balancer 18 via the gears 22 and 20, and the heron balancer 18 rotates in the opposite direction to the crankshaft 12. The gear 20 has a smaller diameter than the gear 22. For this reason, the heron balancer 18 rotates at a faster speed than the crankshaft 12.

  According to the balancer device 10 of the present embodiment, in addition to a normal flywheel (not shown) that rotates integrally with the crankshaft 12, a heron balancer 18 as a sub flywheel is provided, so that the engine Torque fluctuation can be sufficiently reduced. Further, since the heron balancer 18 rotates in the direction opposite to the crankshaft 12, an effect of reducing engine rolling vibration can be obtained. Furthermore, when the heron balancer 18 rotates at a higher speed than the crankshaft 12, the apparent inertia increases. For this reason, even if the mass of the heron balancer 18 is small, the torque fluctuation reducing effect and the rolling vibration reducing effect are greatly exhibited. For this reason, weight can be reduced.

  The balancer device 10 of the present embodiment further has balancer shafts 24 and 26. The balancer shafts 24 and 26 are provided with eccentric masses 28 and 30 and gears 32 and 34, respectively. The gears 32 and 34 mesh with each other, and the gear ratio is 1: 1. Thereby, the balancer shafts 24 and 26 rotate at the same speed in opposite directions. The balancer shaft 24 is further provided with a gear 36. The gear 36 meshes with a gear 38 provided on the crankshaft 12. The gear ratio between the gear 36 and the gear 38 is 1: 1. When the crankshaft 12 rotates, the rotation is transmitted through the gears 38, 36, 32, and 34, and the balancer shafts 24 and 26 rotate. Such balancer shafts 24 and 26 function as a primary balancer that suppresses primary vibration of the engine.

  Oil is stored in an oil pan (not shown) of the engine. The height of the oil surface 50 of the oil in the oil pan is higher than the lower end of the heron balancer 18. That is, the lower end of the heron balancer 18 is slightly immersed in oil. On the other hand, since the outer diameter of the gear 20 is smaller than that of the heron balancer 18, it does not reach the oil level 50. That is, the entire gear 20 is located above the oil level 50 and is not immersed in oil.

  The heron balancer 18 is formed with a plurality of oil blow-off holes 40 for letting the oil in the oil pan fly toward the gear 20. FIG. 2 is a more detailed perspective view of the heron balancer 18. As shown in FIG. 2, the plurality of oil blowing holes 40 are arranged at equal intervals along the circumferential direction. Each oil blowing hole 40 opens to the outer peripheral surface of the heron balancer 18 and the side surface on the gear 20 side, and penetrates between them. In the following description, the former opening is referred to as “outer peripheral surface opening”, and the latter opening is referred to as “side opening”.

  When the heron balancer 18 rotates during engine operation, the outer peripheral surface openings of the oil blow-off holes 40 are sequentially immersed in the oil in the oil pan. If it does so, oil will flow into oil blowing hole 40 vigorously from outer peripheral surface opening, and will jump out from side surface opening. The oil that protrudes from the side opening hits the gear 20 as shown by the arrow in FIG. In this way, oil can be attached to the gear 20. Therefore, the gears 20 and 22 for driving the heron balancer 18 can be lubricated without separately providing a lubricating device such as an oil jet. Therefore, the structure can be simplified and the cost can be reduced.

It is a figure which shows typically the balancer apparatus of Embodiment 1 of this invention. It is a perspective view of the heron balancer with which the balancer apparatus shown in FIG. 1 is provided.

Explanation of symbols

10 balancer device 12 crankshaft 14, 16 crankpin 18 heron balancer 20, 22 gear 24, 26 balancer shaft 28, 30 eccentric mass 32, 34, 36, 38 gear 40 oil blow hole 50 oil level

Claims (1)

A heron balancer partly immersed in the oil in the oil pan,
A gear that rotates integrally with the heron balancer and is not immersed in the oil in the oil pan;
With
The heron balancer is formed with a plurality of oil blow-off holes formed in a direction from the outer periphery to the gear, and when the heron balancer rotates, the gear is caused by oil that has jumped out of the oil blow-off holes. A balancer device for an internal combustion engine characterized by being lubricated.

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