JP3087531B2 - Balancer device for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a balancer for reducing the 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 provided with an unbalance mass is rotated in synchronization with a crankshaft to cancel inertial force of a piston or the like. Yes,
As this type of apparatus, an apparatus disclosed in Japanese Utility Model Laid-Open Publication No. 62-24153 is known.

Referring to FIG. 3, two balancer shafts 95, 9 are provided on the inner periphery of an oil pan 92 provided below an engine block 91, as shown in FIG.
6 is provided in parallel with a crankshaft (not shown). The balancer shafts 95 and 96 are the engine block 9
The shaft 94 is rotatably supported inside a housing 94 disposed between the oil pan 1 and the oil pan 92 to prevent 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 meshing with a gear 93 provided on the crankshaft by a gear 97 formed at the end. 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 lubricating oil may cause noises in the gears and the like, and may promote wear of the gears. there were.

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 rotation transmitting means housed inside a housing connecting a balancer shaft. The purpose is to do.

[0007]

According to the present invention, there is provided an oil pan disposed below an engine block, a balancer housing disposed between the engine block and the oil pan, and an oil pan mounted in the balancer housing. In a balancer device for an internal combustion engine, comprising: a plurality of balancer shafts arranged in parallel with a crankshaft; and driving 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 the upper part of the balancer housing facing the lower part of the crankshaft, and a through hole formed in the bottom of the recess so as to pass through the balancer housing and open above the rotation transmitting means.

[0008]

The lubricating oil that falls from the sliding portion such as the crankshaft into the oil pan accumulates in a concave portion formed in the upper portion of the balancer housing, and the lubricating oil passes through a through hole that opens from the bottom of the concave portion above the rotation transmitting means. Is dropped on the rotation transmitting means inside the balancer housing, and the rotation transmitting means can be smoothly lubricated.

[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 journaled to 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 are balancer shafts 5 and 6.
Is disposed, and the balancer shafts 5 and 6 are respectively supported in parallel with the crankshaft 3 by bearings (not shown) provided inside the balancer housing 4. The balancer housing 4 isolates the inner periphery from the external oil pan 2 and prevents the balancer shafts 5 and 6 from stirring the lubricating oil stored in the oil pan 2.

One end of the balancer shaft 5 protrudes from an opening 44 of the balancer housing 4, and a sprocket 13 is attached to the end of the balancer shaft 5, and 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 twice the speed of the crankshaft 3.

The balancer shaft 5 on the opening 44 side is provided with a gear 15 as rotation transmitting means inside the balancer housing 4, and the 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 has an unbalance mass 5A for imparting an inertial force. Although not shown, the balancer shaft 6 is also provided with a similar unbalance mass to cancel the inertia force of the crankshaft 3 and the like.

Here, the balancer housing 4 includes the gears 15, 1 housed inside the balancer housing 4 below the end of the engine block 1 from which the crankshaft 3 projects.
6 is mounted.

An upper portion 4A is formed in the balancer housing 4 facing the lower side of the crankshaft 3, and a predetermined height from the end of the upper portion 4A facing the balancer chain 7 toward the crankshaft 3 upward in the drawing. Boss 42, 4
2 is a predetermined interval, that is, approximately the balancer shaft 5,
6 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 disposed above the gears 15 and 16 housed in the balancer housing 4 in the drawing. The ribs 41, 4 having a predetermined height from the upper part 4A of the balancer housing 4 are provided at both ends in the length direction.
The bosses 42 and 42 are provided with ribs 41 and 4 respectively.
Contacted by 1. A chain guide 70 for applying tension to the balancer chain 7 is attached to the bosses 42, 42.

An oil reservoir 40 is formed by the recesses defined by the bosses 42, 42 and the ribs 41, 41. The upper portion 4A of the balancer housing 4 serves as the bottom of the oil reservoir 40. Above the position where the gears 15 and 16 housed in the balancer housing 4 mesh with each other, a through hole 43 penetrating through the balancer housing 4 is opened at the bottom of the oil reservoir 40.

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

The configuration is as described above. Next, the operation will be described.

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

The balancer shaft 5 and the gears 15 and 16
The balancer shaft 6 is connected to the balancer shaft 5 at the same speed and in the opposite direction as the balancer shaft 5, and the inertia force of the crankshaft 3, the piston (not shown), etc. To suppress engine vibration.

With the operation of the engine, a journal 3A of the crankshaft 3 is
Lubricating oil is supplied to a moving part 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 provided in the balancer housing 4.
The gears 15 and 16 housed in the gears 15 and 16 are defined as recesses formed 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
Fall and store.

The lubricating oil that has fallen into the oil sump 40 passes through the through-hole 43 provided in the upper part 4A of the balancer housing 4 and the gear 1
The gears 15 and 16 further fall to the meshing positions 5 and 16 and lubricate the gears 15 and 16 housed in the balancer housing 4.

Thus, an oil sump 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 formed at the bottom of the oil sump 40 above the meshing position of the gears 15 and 16. 4 is formed, the lubricating oil falling from the journal portion 3A of the crankshaft 3 and the like is formed in the oil reservoir 40.
Gears 15 and 16 through the through holes 43.
Gears 15 and 1 connecting the balancer shafts 5 and 6 without requiring a special lubrication device.
6 can be performed smoothly, and 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 support rigidity of the chain guide 70 is high.
The flapping of the balancer chain 7 can be effectively suppressed. Therefore, vibration input to the balancer housing 4 due to the fluctuation of the tension of the balancer chain 7 can be suppressed as much as possible.

[0028]

As described above, according to the present invention, a through-hole is provided which penetrates through the bottom of the recess formed in the upper part of the balancer housing and opens above the rotation transmitting means. Lubricating oil that falls into the oil pan is dropped onto the rotation transmitting means inside the balancer housing via the concave portion and the through hole, and the rotation transmitting means can be smoothly lubricated without requiring a special lubricating device. It is possible to provide a balancer device with high quietness and high durability by reducing noise from rotation transmission means and reducing wear.

[Brief description of the 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 sectional view of an engine showing a conventional example.

[Explanation of symbols]

 Reference Signs List 1 engine block 2 oil pan 3 crankshaft 4 housing 5, 6 balancer shaft 7 balancer chain 12, 13 sprocket 15, 16 gear 40 oil sump 43 through hole

Claims (1)

(57) [Claims] 1. An oil pan disposed below an engine block, a balancer housing disposed between the engine block and the oil pan, and accommodated in the balancer housing and disposed in parallel with the crankshaft. In a balancer device for an internal combustion engine, comprising: a plurality of balancer shafts; and a driving unit that transmits rotation of a crankshaft to the balancer shaft. A rotation transmitting unit that synchronously rotates the plurality of balancer shafts; A balancer device for an internal combustion engine, comprising: a recess formed in the upper portion of the balancer housing facing the bottom surface; and a through hole formed in the bottom of the recess so as to penetrate the balancer housing and open above the rotation transmitting means.