JPH0783017A - Balancer device of internal combustion engine - Google Patents

Abstract

PURPOSE:To feed lubrication oil smoothly to gears housed inside a housing. CONSTITUTION:The device is housed in a balancer housing 4 arranged between an engine block 1 and an oil pan 2, and is equipped with balancer shafts 5, 6 arranged in parallel with a crankshaft 3; a balancer chain 7 that transmits the rotation of the crankshaft 3 to the balancer shaft 5 through a sprocket 13; gears 15, 16 to rotate the balancer shafts 5, 6 synchronously; and a through- hole 43 that opens at the upper part of the gears 15, 16 and penetrates the balancer housing 4 at the bottom portion of an oil pool 40 facing the lower part of the crankshaft 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved balancer device for reducing vibration of an internal combustion engine.

[0002]

2. Description of the Related Art As a balancer device for reducing vibration generated in an internal combustion engine of an automobile or the like, a balancer shaft having an unbalanced mass is rotated in synchronization with a crankshaft to cancel inertial force of a piston or the like. Yes,
A device disclosed in Japanese Utility Model Laid-Open No. 62-24153 is known as this type of device.

Explaining this device, as shown in FIG. 3, two balancer shafts 95, 9 are provided on the inner circumference of an oil pan 92 arranged below the engine block 91.
6 is provided in parallel with a crankshaft (not shown). The balancer shafts 95 and 96 are engine blocks 9
1 and an oil pan 92, which is axially supported inside a housing 94, which prevents the balancer shafts 95 and 96 from stirring the lubricating oil in the oil pan 92.

The balancer shaft 95 is driven by the crankshaft by engaging a gear 97 formed at the end thereof with a gear 93 provided on the crankshaft. The balancer shaft 96 is connected to the balancer shaft 95 via a gear or the like (not shown) inside the housing 94, and the balancer shaft 96 rotates in the opposite direction to the balancer shaft 95 to suppress engine vibration.

[0005]

However, in such a conventional balancer device for an internal combustion engine, since the inside of the housing is isolated from the oil pan 92,
Lubricating oil may not be smoothly supplied to the gears connecting the balancer shafts 95 and 96, and the lack of the lubricating oil may cause noise in the gears and promote wear of the gears. there were.

Therefore, the present invention has been made in view of the above problems, and provides a balancer device for an internal combustion engine capable of smoothly supplying lubricating oil to a rotation transmitting means housed inside a housing for connecting a balancer shaft. The purpose is to do.

[0007]

According to the present invention, there is provided an oil pan arranged below an engine block, a balancer housing arranged between the engine block and the oil pan, and a balancer housing. A balancer device for an internal combustion engine, comprising: a plurality of balancer shafts arranged in parallel with a crankshaft; and a drive means for transmitting rotation of the crankshaft to the balancer shaft. A rotation transmission for synchronously rotating the plurality of balancer shafts. Means, a recess formed in an upper portion of the balancer housing facing the crankshaft downward, and a through hole opened at an upper portion of the rotation transmitting means through the balancer housing at a bottom portion of the recess.

[0008]

The lubricating oil that falls from the sliding portion of the crankshaft or the like into the oil pan collects in the concave portion formed in the upper portion of the balancer housing, and the lubricating oil flows from the bottom portion of the concave portion through the through hole that opens above the rotation transmitting means. Is dropped onto the rotation transmitting means inside the balancer housing, and the rotation transmitting means can be lubricated smoothly.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

As shown in FIGS. 1 and 2, a crankshaft 3 is axially supported by an engine block 1 of an in-line engine via a journal portion 3A, and an oil pan 2 for storing lubricating oil is provided below the engine block 1. Are combined.

Below the crankshaft 3 between the engine block 1 and the oil pan 2, the balancer shafts 5, 6 are provided.
A balancer housing 4 accommodating the above is disposed, and the balancer shafts 5 and 6 are supported in parallel with the crankshaft 3 by bearings (not shown) provided inside the balancer housing 4. The balancer housing 4 separates the inner circumference from the external oil pan 2, and the balancer shafts 5 and 6 prevent the lubricating oil stored in the oil pan 2 from being stirred.

One end of the balancer shaft 5 projects from the opening 44 of the balancer housing 4, a sprocket 13 is attached to the end of the balancer shaft 5, and the balancer shaft 5 is provided on the crankshaft 3 via a balancer chain 7 as a driving means. The gear ratio of the sprockets 12 and 13 is preset so that the balancer shaft 5 is connected to the sprocket 12 and rotates at a speed twice that of the crankshaft 3.

The balancer shaft 5 on the side of the opening 44 is provided with a gear 15 as a rotation transmitting means inside the balancer housing 4, and a balancer shaft 6 axially supported in parallel with the balancer shaft 5 meshes with the gear 15. Gear 16
Is provided. The gears 15 and 16 are set to have the same number of teeth and rotate in opposite directions at the same speed.

The balancer shaft 5 is provided with an unbalanced mass 5A for giving an inertial force, and although not shown, the balancer shaft 6 is also provided with a similar unbalanced mass to cancel out the inertial force of the crankshaft 3 and the like.

Here, the balancer housing 4 has gears 15 and 1 housed inside the balancer housing 4 below the end of the engine block 1 from which the crankshaft 3 projects.
6 is mounted so that it is arranged.

An upper portion 4A is formed on the balancer housing 4 facing the lower side of the crankshaft 3, and a predetermined height upward from the end of the upper portion 4A facing the balancer chain 7 toward the crankshaft 3 in the figure. And the bosses 42, 4
2 is a predetermined distance, that is, approximately the balancer shaft 5,
6 are projected at positions corresponding to the upper side in the figure.

The boss 42 has a predetermined length in the axial direction of the balancer shafts 5 and 6, and is arranged above the gears 15 and 16 housed in the balancer housing 4 in the figure, while the bosses 42 and 42 are arranged. Ribs 41, 4 of a predetermined height from the upper portion 4A of the balancer housing 4 at both ends in the length direction of the
1 are erected respectively, and the bosses 42, 42 are ribs 41, 4
Contacted by 1. A chain guide 70 that applies tension to the balancer chain 7 is attached to the bosses 42, 42.

An oil sump 40 is formed by the recess defined by the bosses 42, 42 and ribs 41, 41, and the upper portion 4A of the balancer housing 4 serves as the bottom of the oil sump 40. A through hole 43 that penetrates the balancer housing 4 is opened at the bottom of the oil sump 40 above the position where the gears 15 and 16 housed in the balancer housing 4 mesh with each other.

A sprocket 14 for driving a valve operating mechanism (not shown) is provided between the end of the engine block 1 and the sprocket 12 via a timing chain 8.

With the above construction, the operation will be described below.

With the rotation of the crankshaft 3, the balancer shaft 5 rotates at twice the speed via the sprockets 12 and 13 and the balancer chain 7.

The balancer shaft 5 and the gears 15 and 16
The balancer shaft 6 connected via the rotary shaft rotates at the same speed as the balancer shaft 5 in the opposite direction, and the balancer shafts 5 and 6 which rotate in the opposite direction are provided with unbalanced masses, thereby the inertia force of the crankshaft 3, a piston (not shown) and the like. To suppress the engine vibration.

Along with the operation of the engine, the lubrication hydraulic pressure feeding means (not shown) from the journal portion 3A of the crankshaft 3,
Lubricating oil is supplied to moving parts such as the timing chain 8 or the sprocket 14, and the lubricating oil that has lubricated a predetermined moving part falls into the oil pan 2.

Here, the oil sump 40 is the balancer housing 4
Of the gears 15 and 16 housed in the crankshaft 3 are defined as recesses by the bosses 42 and 42 and the ribs 41 and 41 projecting upward in the drawing.
The lubricating oil that lubricates the timing chain 8 is the oil sump 40.
It falls and is stored.

The lubricating oil dropped into the oil sump 40 is passed through the through hole 43 provided in the upper portion 4A of the balancer housing 4 to the gear 1
The gears 15 and 16 housed in the balancer housing 4 are lubricated by further dropping to the meshing positions of 5 and 16.

Thus, the oil reservoir 40 as a recess is formed in the upper portion 4A of the balancer housing 4 facing the lower side of the crankshaft 3, and the balancer housing is provided at the bottom of the oil reservoir 40 above the meshing position of the gears 15 and 16. Since the through-hole 43 that penetrates 4 is formed, the lubricating oil that falls from the journal portion 3A of the crankshaft 3 or the like is stored in the oil reservoir 40.
And the gears 15, 16 through the through hole 43.
The gears 15, 1 for connecting the balancer shafts 5, 6 without dropping a special lubricating device on the gears
6 can be lubricated smoothly, noise from the gears 15 and 16 can be reduced, and wear can be suppressed.

Further, since the boss 42 for mounting the chain guide 70 for guiding the balancer chain 7 is connected by the rib 41, the supporting rigidity of the chain guide 70 is high,
Flapping of the balancer chain 7 can be effectively suppressed. Therefore, the vibration input to the balancer housing 4 due to the tension fluctuation of the balancer chain 7 can be suppressed as much as possible.

[0028]

As described above, according to the present invention, since the through hole which penetrates the bottom of the recess formed in the upper portion of the balancer housing and opens above the rotation transmitting means is provided, the sliding portion such as the crankshaft is prevented. Lubricating oil that drops into the oil pan is dropped onto the rotation transmitting means inside the balancer housing through the recess and the through hole, and it is possible to smoothly lubricate the rotation transmitting means without requiring a special lubricating device. It is possible to provide a balancer device that reduces noise from the rotation transmitting means and reduces wear, and that has high silence and durability.

[Brief description of drawings]

FIG. 1 is a front view of an engine showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a partial cross-sectional view of an engine showing a conventional example.

[Explanation of symbols]

 1 Engine Block 2 Oil Pan 3 Crank Shaft 4 Housing 5, 6 Balancer Shaft 7 Balancer Chain 12, 13 Sprocket 15, 16 Gear 40 Oil Reservoir 43 Through Hole

Claims (1)

[Claims] 1. An oil pan disposed below the engine block, a balancer housing disposed between the engine block and the oil pan, and a balancer housing housed in parallel with the crankshaft. A balancer device for an internal combustion engine, comprising: a plurality of balancer shafts; and a drive means for transmitting rotation of a crankshaft to the balancer shaft, a rotation transmitting means for synchronously rotating the plurality of balancer shafts, and a lower portion of the crankshaft. A balancer device for an internal combustion engine, comprising: a recess formed in an upper portion of the balancer housing facing the above; and a through hole that penetrates the balancer housing and is opened above the rotation transmission means at the bottom of the recess.