JP2022139430A - Balancer device and internal combustion engine including the same - Google Patents

Abstract

To provide a balancer device of an internal combustion engine which can effectively radiate heat of bearing parts supporting a first balancer shaft to which a balancer drive gear is fixed, and to provide a balancer device with an oil pump.SOLUTION: A balancer device of an internal combustion engine has: a suction opening of an oil strainer which is provided between a first bearing part of a first balancer shaft and a second bearing part of the first balancer shaft in a direction of a rotation axis of the first balancer shaft and is open to the side of an oil pan; and an oil suction passage of the oil strainer which extends from the suction opening toward the first bearing part of the first balancer shaft and is connected to a suction part of an oil pump. The suction opening of the oil strainer and the oil suction passage of the oil strainer are formed integrally with a housing. The oil suction passage extending from the suction opening of the oil strainer toward the oil pump is formed integrally with the housing, and thus an oil flowing in the oil suction passage can efficiently carry heat of the bearing parts of the first balancer shaft away through a metal forming the housing.SELECTED DRAWING: Figure 10

Description

The present invention relates to a balancer device for an internal combustion engine and an internal combustion engine equipped with this balancer device, and more particularly to a balancer device for transmitting rotation of a crankshaft to the balancer device through a crank gear (engine-side gear) and an internal combustion engine equipped with this balancer device. It is about.

A general internal combustion engine is provided with a balancer device that rotatably accommodates a first balancer shaft driven by a crankshaft and a second balancer shaft driven by the first balancer shaft. to reduce vibrations generated in the internal combustion engine.

Balancer weights are provided on the first balancer shaft and the second balancer shaft, and the first balancer shaft and the second balancer shaft are rotated at twice the rotational speed of the crankshaft, causing the crankshaft to rotate at twice the rotational speed of the crankshaft. Vibration of the internal combustion engine is reduced by balancing the inertial force with the inertial force generated by the first balancer shaft and the second balancer shaft.

In this balancer device, as disclosed in International Publication No. WO 2017/141917 (Patent Document 1), the balancer device is fastened to the lower portion of the internal combustion engine main body and arranged in the oil pan, and the first of the two balancer shafts is installed. The balancer shaft is rotationally driven by a crank gear (rotated by the crankshaft), the first balancer shaft drives the second balancer shaft through synchronous gear transmission means, and the second balancer shaft drives the oil pump. driving the

In this balancer device, a first balancer shaft and a second balancer shaft arranged in parallel are provided, and gears in which a first gear and a second gear are meshed with one ends of the first balancer shaft and the second balancer shaft, respectively. A transmission mechanism is provided. In this case, the first gear and the second gear have the same number of teeth, and the first balancer shaft and the second balancer shaft rotate synchronously at the same number of revolutions.

A balancer drive gear is provided at the other end of the first balancer shaft, and a reduction gear for driving the oil pump is provided at the other end of the second balancer shaft. meshed with a pump drive gear fixed to the Since the crank gear rotated by the internal combustion engine is meshed with the balancer drive gear of the first balancer shaft, when the crank gear is rotated by the crankshaft of the internal combustion engine, this rotation is the balancer drive gear → the first balancer shaft. The balancer shaft→first gear→second gear→second balancer shaft→reduction gear→pump drive gear, and finally the oil pump is rotated and driven.

Here, the balancer drive gear, the first balancer shaft, the first gear, the second gear, the second balancer shaft, and the reduction gear described above are mounted on the lower housing, and are combined with the lower housing. It is covered by the housing and housed in the space formed by both housings.

Since the crank gear meshes with the balancer drive gear from above, the upper housing in the area where the balancer drive gear and the pump drive gear arranged close thereto are located is cut open. .

WO 017/141917

By the way, the crank gear is assembled with the balancer drive gear facing downward (not necessarily directly downward). , towards the balancer drive gear. Therefore, the first balancer shaft to which the balancer drive gear is fixed is strongly pressed against the bearing portion that supports the first balancer shaft, and a large amount of heat is generated in this pressed portion.

When the bearing heats up, the gap between the bearing and the first balancer shaft increases, causing the first balancer shaft to move in the gap between the bearing and the tooth between the crank gear and the balancer drive gear. There is a phenomenon that the hitting sound becomes louder.

Therefore, in order to suppress the rattling noise, it is required to effectively dissipate the heat of the bearing portion that bears the first balancer shaft to which the balancer drive gear is fixed. Therefore, it is rational to dissipate the heat using the lubricating oil stored in the oil pan.

However, in the balancer device disclosed in Patent Document 1, the oil suction passage leading from the oil strainer to the oil pump is provided with a gap from the outer surface of the lower housing. The heat of the shaft bearing cannot be carried away efficiently.

SUMMARY OF THE INVENTION An object of the present invention is to provide a balancer device for an internal combustion engine capable of effectively dissipating heat from a bearing portion that supports a first balancer shaft to which a balancer drive gear is fixed, and an internal combustion engine equipped with this balancer device. That's what it is.

The present invention
A balancer device for an internal combustion engine having at least an oil pump for sucking oil from an oil pan, and a balancer body to which the oil pump is attached and which is housed inside a housing space formed in a housing,
The balancer body has a balancer shaft provided with a balancer drive gear that meshes with at least the crank gear of the internal combustion engine,
A balancer shaft first bearing provided at a position on the side of the balancer drive gear of the first balancer shaft in the direction of the rotation axis of the balancer shaft housed in the housing and supporting the balancer shaft; and a balancer drive gear of the balancer shaft. a balancer shaft second bearing provided on the opposite side and pivotally supporting the balancer shaft;
Suction of an oil strainer provided between at least the first balancer shaft bearing portion and the second balancer shaft bearing portion in the direction of the rotation axis and having an opening in the direction orthogonal to the rotation axis so as to allow the oil in the oil pan to be sucked. and an oil suction passage of the oil strainer extending from the oil suction opening along the balancer shaft and connected to the suction portion of the oil pump, wherein the oil suction opening of the oil strainer and the oil suction passage of the oil strainer are connected to each other. It is characterized by being formed in a housing.

According to the present invention, the oil suction passage extending from the oil suction opening of the oil strainer to the oil pump is formed integrally with the housing. The heat of the bearing portion of the balancer shaft can be removed efficiently. As a result, it is possible to suppress an increase in rattling noise between the crank gear and the balancer drive gear.

1 is a cross-sectional view showing a cross-section of an internal combustion engine provided with a balancer device; FIG. FIG. 2 is an exploded perspective view of the balancer device shown in FIG. 1; BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which carried out the cross section of the balancer apparatus which becomes the 1st Embodiment of this invention in the axial direction. FIG. 4 is a top view of the balancer device shown in FIG. 3 as seen from the upper side housing; FIG. 4 is an external perspective view of the balancer device viewed from the lower left side of the lower housing; FIG. 4 is an external perspective view of the balancer device viewed from the lower right side of the lower housing; FIG. 4 is an external view of the lower housing before assembly as seen from the outside; FIG. 4 is an external view of the inside of the lower housing before assembly; FIG. 4 is an explanatory diagram for explaining a meshing state of a crank gear, a balancer drive gear 15, a reduction gear 21, and a pump drive gear; FIG. 5 is a sectional view of the AA section of FIG. 4; FIG. 5 is a cross-sectional view of the BB cross section of FIG. 4; FIG. 5 is a sectional view of the CC section of FIG. 4;

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments, and various modifications and applications can be made within the technical concept of the present invention. is also included in the scope.

Before describing the embodiment of the present invention, first, the installation state of the internal combustion engine and the balancer device will be described based on FIG. FIG. 1 shows a longitudinal section of an internal combustion engine 01. As shown in FIG. The internal combustion engine 01 is, for example, an in-line four-cylinder reciprocating internal combustion engine. A cylinder block 03 is provided below the cylinder head 02 , and a cylinder block 04 is fixed to the lower surface of the cylinder block 03 . A crankshaft (not shown) is rotatably supported by the cylinder block 04, and the axial direction of the crankshaft is arranged along the longitudinal direction of the internal combustion engine.

The internal combustion engine 01 is mounted on the vehicle such that the crankshaft is oriented laterally with respect to the longitudinal direction of the vehicle body, and a crank gear (not shown) is fixed to a part of the crankshaft in the axial direction. The crank gear is a driving gear for driving the balancer device 10, which will be described later.

Further, an oil pan 05 for storing lubricating oil is attached to the lower portion of the cylinder block 04. Inside the oil pan 05 is a balancer device for suppressing secondary vibration of the internal combustion engine 01. 10 are accommodated. The oil pan 05 is provided on the opposite side (ground side) of the internal combustion engine, and stores lubricating oil to lubricate the sliding parts of the internal combustion engine.

The balancer device 10 has an upper housing, a lower housing, a balancer main body, and an oil pump 11, details of which will be described later. The upper housing and the lower housing are fixed to the lower surface of the cylinder block 04 by a plurality of balancer fastening bolts 06 so as to overlap vertically. Further, the oil pump 11 is connected to and integrated with the balancer device 10 by a plurality of oil pump fastening bolts 07 . The oil pump 11 is a variable displacement oil pump that changes the amount of change in the volume of the pump chamber according to a predetermined operating state.

The variable displacement oil pump used in the present embodiment is a vane pump having a mechanism for reducing the amount of change in the volume of the pump chamber during high speed rotation of the pump. things are used. The oil pump 11 is fixed to the front side of the lower housing with a plurality of oil pump fastening bolts 07 . Since the oil pump 11 is attached to the lower housing, high support rigidity can be obtained.

By the way, as described above, the crank gear that drives the balancer device 10 is assembled so as to press the balancer drive gear downward (oil pan side) in order to properly mesh with the balancer drive gear. Therefore, the first balancer shaft to which the balancer drive gear is fixed is strongly pressed against the bearing portion that supports the first balancer shaft, and a large amount of heat is generated in this pressed portion.

When the bearing heats up, the gap between the bearing and the first balancer shaft increases, causing the first balancer shaft to move in the gap between the bearing and the tooth between the crank gear and the balancer drive gear. There is a phenomenon that the hitting sound becomes louder.

In order to suppress this rattling noise, it is necessary to effectively dissipate the heat of the bearing portion that bears the first balancer shaft to which the balancer drive gear is fixed. Therefore, it is rational to dissipate the heat using the lubricating oil stored in the oil pan.

However, in the balancer device disclosed in Patent Document 1, the oil suction passage leading from the oil strainer to the oil pump is provided with a gap from the outer surface of the lower housing. There is a problem that the heat of the bearing portion of the shaft cannot be removed efficiently.

In terms of manufacturing, the oil intake passage from the oil strainer to the oil pump is spaced from the outer surface of the lower housing. For this reason, it is necessary to manufacture the oil strainer separately, and then fix the oil strainer to the lower housing again, which raises the problem of increased manufacturing costs.

Therefore, in this embodiment, the oil suction opening of the oil strainer that opens on the oil pan side shown in FIG. It is characterized in that it is formed integrally with the lower housing.

Since the oil suction passage leading from the oil suction opening of the oil strainer to the oil pump is formed integrally with the lower housing, the oil flowing through the oil suction passage passes through the metal forming the housing to the first balancer shaft. heat from the bearing can be efficiently removed.

In addition, since the oil suction opening and the oil suction passage of the oil strainer are integrally formed in the lower housing, it is no longer necessary to manufacture the oil strainer separately and then fix the oil strainer to the housing again. An increase in manufacturing cost can be suppressed.

A first embodiment of the present invention will be described in detail below with reference to FIGS. 2 to 12. FIG. FIG. 2 is an oblique view of the balancer device 10 disassembled for each component. The left side of the drawing is the front side (front side) of the vehicle, and the right side of the drawing is the rear side (rear side) of the vehicle. The balancer device 10 is fixed to the cylinder block 04 with balancer fastening bolts 06 as shown in FIG.

In FIG. 2, the storage space formed by the lower housing 12 and the upper housing 13 accommodates a balancer body that suppresses vibrations of the internal combustion engine. A pump 11 is fixed by an oil pump fastening bolt 07 . The oil pump 11 is provided with an oil discharge port 27 for discharging the sucked oil. The oil discharged from the oil discharge port 27 is sent to the internal combustion engine, lubricates the mechanical sliding parts of the internal combustion engine, and then is collected in the oil pan.

The balancer main body is composed of a first rotation system having a balancer weight and a second rotation system which also has a balancer weight. The rotation of the first rotation system is reversed by a gear transmission mechanism to rotate the second rotation system. It has become. By rotating the first rotation system and the second rotation system, a vibratory force is generated, and a vibratory force having a phase opposite to the secondary component of the vibratory force of the internal combustion engine caused by the reciprocating motion of the piston is generated. to reduce the vibration of the internal combustion engine.

The first rotation system includes a balancer drive gear 15 fixed to both ends of a first balancer shaft 14, a first gear 16, a first balancer shaft second bearing portion 17 that supports the first balancer shaft 14, and a first balancer. It is composed of a shaft first bearing portion 18 and a first balancer weight 19 provided on the first balancer shaft 14 .

The first balancer shaft second bearing portion 17 and the first balancer shaft first bearing portion 18 are supported between the lower housing 12 and the upper housing 13, thereby rotating and supporting the first balancer shaft 14. be. Also, the balancer drive gear 15 and the first gear 16 are rotatably housed in the housing space between the lower housing 12 and the upper housing 13 .

On the other hand, the second rotation system includes a reduction gear 21 fixed to both ends of a second balancer shaft 20, a second gear 22, a second balancer shaft second bearing 23 that supports the second balancer shaft 20, and a second balancer. It is composed of a shaft first bearing portion 24 and a second balancer weight 25 provided on the second balancer shaft 23 . Here, the reduction gear 21 is meshed with a pump driving gear (see the pump driving gear 48 shown in FIG. 9) fixed to the rotary shaft of the oil pump 11 to rotate the pump driving gear.

The second balancer shaft second bearing 23 and the second balancer shaft first bearing 24 are supported between the lower housing 12 and the upper housing 13, thereby rotating and supporting the second balancer shaft 20. is. Also, the reduction gear 21 and the second gear 22 are rotatably housed in a housing space between the lower housing 12 and the upper housing 13 . The lower housing 12 and the upper housing 13 are integrated with each other by housing fixing bolts 08 .

Here, since the pump driving gear is integrally fixed to the oil pump 11, it cannot be seen in the drawing of FIG.

When the crank gear fixed to the crankshaft disposed above the balancer device 10 rotates, the balancer driving gear 15 rotates at a rotational speed twice that of the crank gear, and the balancer driving gear rotates. The first balancer shaft 14 to which 15 is fixed is also rotated. Further, by rotating the second gear 22 meshing with the first gear 16 fixed to the first balancer shaft 14, the second balancer shaft 20 phase-adjusted with the first balancer shaft 14 is rotated, and the balancer vibrates. generating power.

The balancer device 10 reduces the vibration of the internal combustion engine by generating a vibrational force having a phase opposite to the secondary component of the vibrational force of the internal combustion engine caused by the reciprocating motion of the piston. Such a balancer device 10 is well known.

FIG. 3 shows an axial cross section of the balancer device 10 . In FIG. 3 , an oil pump 11 is fixed to the rear side of the balancer device 10 and is rotationally driven by a second balancer shaft 20 incorporated in the balancer device 10 . The balancer device 10 has a balancer body housed in a storage space formed by a lower housing 12 and an upper housing 13 .

3 shows a cross section of the second balancer shaft 20 side, and a balancer drive gear 15 is fixed to the end face of the first balancer shaft 14 (see FIG. 2) on the oil pump 11 side. The balancer drive gear 15 is rotated and driven by a crank gear (see crank gear 47 shown in FIG. 9) rotated by the crankshaft.

A reduction gear 21 that meshes with the pump driving gear of the oil pump 11 is fixed to one end of the second balancer shaft 20, and a second gear 22 that constitutes a gear transmission mechanism is attached to the other end of the second balancer shaft 20. Fixed. The second gear 22 is configured to mesh with the first gear 16 fixed to the first balancer shaft 14, as shown in FIG. Furthermore, a second balancer weight 25 is provided on the second balancer shaft 20 between the reduction gear 21 and the second gear 22 .

The space between the second balancer weight 25 and the second gear 22 is supported by a second balancer shaft second bearing portion 23, and the space between the balancer weight 25 and the reduction gear 21 is supported by a second balancer shaft first bearing portion 24. ing. The second balancer shaft second bearing portion 23 and the second balancer shaft first bearing portion 24 are supported by bearing support portions provided inside the lower housing 12 . Also, the first balancer shaft second bearing portion 17 and the first balancer shaft first bearing portion 18 have the same configuration.

The second balancer shaft second bearing portion 23 and the second balancer shaft first bearing portion 24, and the first balancer shaft second bearing portion 17 and the first balancer shaft first bearing portion 18 use rolling bearings or plain bearings. However, in this embodiment, plain bearings are used.

A pump driving gear (see a crank gear 48 shown in FIG. 9) is fixed to the rotating shaft of the oil pump 11 and rotated by a reduction gear 21 fixed to the end surface of the second balancer shaft 20 . A pump driving gear of the oil pump 11 is integrated with the oil pump 11 and meshes with the reduction gear 21 by being assembled to the balancer device 10 . Therefore, the pump driving gear is arranged between the oil pump 11 side end surfaces of the lower housing 12 and the upper housing 13 and the oil pump 11 .

An exposure opening (see FIG. 4) is formed in the area of the upper housing 13 where the balancer driving gear 15 is arranged, and a part of the balancer driving gear 15 is exposed by protruding upward from this exposure opening. . This allows meshing with the crank gear. An oil-proof wall (see FIG. 4) is formed on the upper housing 13 to cover the pump drive gear from above, on the oil pump 11 side of the exposure opening.

An oil strainer 28 that sucks the lubricating oil stored in the oil pan 05 (see FIG. 1) and supplies it to the oil suction port 26 of the oil pump 11 is integrated with the lower side (on the oil pan side) of the lower housing 12 . is formed In other words, the oil strainer 28 and the lower housing 11 are integrally and inseparably formed by the metal forming the lower housing 12 .

Here, the oil strainer 28 includes an oil suction opening 29 opened in the oil pan 05 , a filter member 30 arranged in the oil suction opening 29 , the oil suction opening 29 and the oil suction port 26 of the oil pump 11 . It includes the connecting oil suction passage 31 and the pipe wall portion forming the oil suction opening 29 and the oil suction passage 31 .

The oil intake opening 29 and the oil intake passage 31 are formed integrally with the lower housing 12 as described above. That is, when the lower housing 12 is formed by casting or the like, the oil intake opening 29 and the oil intake passage 31 are formed at the same time. Therefore, the lubricating oil flowing through the oil intake passage 31 comes into direct contact with the metal forming the lower housing 12 .

As shown in FIG. 3, the oil strainer 28 has an oil intake passage 31 formed parallel to the second balancer shaft 20 and the first balancer shaft 14 (not shown). Therefore, the axis CA of the oil intake passage 31 is parallel to the rotation axes of the second balancer shaft 20 and the first balancer shaft 14 (not shown).

Thus, the oil intake passage 31 has an elongated hole shape along the longitudinal direction of the second balancer shaft 20 . Also, the oil suction opening 29 of the oil strainer 28 is formed so as to protrude toward the lubricating oil stored in the oil pan 05 . In other words, the oil intake opening 29 opens on the opposite side of the upper housing 13 and extends away from the outer surface of the lower housing 12 . The axis CB of the oil intake opening 29 and the axis CA of the oil intake passage 31 are perpendicular to each other, but do not intersect as shown in FIG.

As described above, in the balancer device 10 of the present embodiment, in the direction of the rotation axis of the first balancer shaft 14 housed in the housings 12 and 13, the balancer driving gear 15 side of the first balancer shaft 14 has A first balancer shaft first bearing portion 18 provided in a housing which is provided to support the first balancer shaft 14, and a first balancer shaft provided at a position on the opposite side of the balancer drive gear of the first balancer shaft to support the first balancer shaft. and a first balancer shaft second bearing portion provided in a housing that connects at least the first balancer shaft first bearing portion 18 and the first balancer shaft second bearing portion 17 in the direction of the rotation axis of the first balancer shaft 14. A suction opening 29 of an oil strainer 28 which is provided between and is open to allow the oil in the oil pan to be sucked in the direction orthogonal to the rotation axis, and a first balancer shaft along the first bearing portion 18 from the suction opening 29. The oil strainer has an oil suction passage 31 extending along the length of the oil pump and connected to the suction portion 26 of the oil pump, and the oil strainer suction opening 29 and the oil strainer oil suction passage 31 are integrally formed in the housing. .

Here, the oil intake passage 3 1 is positioned below the second balancer shaft 20 (on the oil pan 05 side) when viewed from a plane perpendicular to the rotation axis of the second balancer shaft 20 . Further, it is located between the second balancer shaft second bearing portion 23 and the second balancer shaft first bearing portion 24 , extends along the second balancer shaft 20 and is connected to the oil suction port 26 of the oil pump 11 . there is This position is because the oil suction port 26 of the oil pump 11 is arranged on the second balancer shaft 20 side.

However, since the first balancer shaft 14 is arranged parallel to the second balancer shaft 20, the oil intake passage 31 is the same as that of the first balancer shaft 14 when viewed from a plane orthogonal to the rotation axis of the first balancer shaft 14. It can be seen that it is positioned below the shaft 14 (on the oil pan 05 side). Further, it is positioned between the first balancer shaft second bearing portion 17 and the first balancer shaft first bearing portion 18, extends along the first balancer shaft 14, and is connected to the suction portion 26 of the oil pump. You can also see

Next, the structure of the balancer device 10 viewed from the upper housing 13 side will be described. In FIG. 4, the upper housing 13 has an exposure opening 32 formed in a region where the balancer driving gear 15 is arranged, and a portion of the balancer driving gear 15 protrudes upward from the exposure opening 32 and is exposed. . This allows meshing with the crank gear. An oil-proof wall 33 is formed on the upper housing 13 on the side of the oil pump 11 from the exposure opening 32 to cover the pump drive gear from above.

Also, it will be explained later. The upper housing 13 is formed with an oil introduction opening 45 for introducing lubricating oil from the internal combustion engine. This oil introduction opening 45 is connected to the oil introduction opening 44 (see FIG. 8) of the lower housing 12 .

Next, the shape and the like of the oil strainer 28, which characterizes this embodiment, will be described with reference to FIGS. 3 and 5 to 12. FIG.

Here, FIG. 5 is an external perspective view of the balancer device 10 formed in the lower housing 12 and viewed from the lower left side on the left side of the intake opening 29 of the oil strainer, and FIG. 7 is an external perspective view of the intake opening 29 of the oil strainer formed in 12 as viewed from the lower right side on the right side, FIG. 7 is an external view of the lower housing 12 before assembly as viewed from below, and FIG. 4] is an external view of the lower housing 12 before assembly as viewed from the inside. [FIG.

9 is an explanatory diagram for explaining the engagement state of the crank gear, the balancer drive gear 15, the reduction gear 1, and the pump drive gear, and FIG. 11 is a sectional view of the BB section of FIG. 4, and FIG. 12 is a sectional view of the CC section of FIG.

First, in FIGS. 5 and 6, the balancer device 10 has a lower housing 12 and an upper housing 13 that are integrated with housing fixing bolts 08 . An oil strainer 28 is formed in the lower housing 12 . As described above, the oil strainer 28 and the lower housing 11 are integrally and inseparably formed by the metal forming the lower housing 12 .

The oil strainer 28 is formed to protrude from the outer surface of the lower housing 12 opposite to the upper housing 13 toward the lubricating oil stored in the oil pan 05 . That is, the oil suction passage forming wall 34 forming the oil suction passage 31 (see FIG. 3) is formed in a shape protruding from the outer surface of the lower housing 12 toward the lubricating oil side of the oil pan 05 . Similarly, an oil suction opening forming wall 35 forming the oil suction opening 29 (see FIG. 3) is formed in a shape protruding from the surface of the lower housing 12 toward the lubricating oil side of the oil pan 05 .

Since the oil suction passage forming wall 34 and the oil suction opening forming wall 35 are shaped to protrude from the outer surface of the lower housing 12 in this way, heat can flow in and out of these portions to a great extent, and the heat of the bearing portion can be increased. make it easier to escape.

FIG. 7 shows the outer surface of the lower housing 12 on the side not coupled with the upper housing 13 . In FIG. 7, the left end side is the side where the first gear 16 and the second gear 22 are located, and the right end side is the side where the balancer driving gear 15 and the reduction gear 21 are located. Therefore, the first balancer shaft 14 and the second balancer shaft 20 are arranged parallel to each other from the left end to the right end.

An oil suction opening forming wall 35 formed in the lower housing 12 is formed in an annular shape, and an oil suction opening 29 is formed therein. As shown in FIG. 3, the oil suction opening forming wall 35 exists to a position where it overlaps the area of the second balancer shaft second bearing 23 of the second balancer shaft 20 .

In other words, when viewed in the direction of the rotation axis of the second balancer shaft 20, the area where the second balancer shaft second bearing 23 is formed and the area where the oil intake opening 29 is formed overlap with each other with the metal portion of the lower housing 12 interposed therebetween. there is As a result, the second balancer shaft second bearing 23 and the oil suction opening 29 are brought closer to each other to enhance heat transfer. The same can be said for the first balancer shaft 14 as well.

The oil suction opening forming wall 35 is continuously connected to the oil suction passage forming wall 34 , and the oil suction passage 31 formed therein is connected to the oil suction port 26 of the oil pump 11 . . The oil intake passage forming wall 34 is formed parallel to the second balancer shaft 20 .

Therefore, as shown in FIG. 3, the region where the second balancer shaft first bearing portion 24 is formed and the region where the oil intake passage 31 is formed overlap with each other with the metal portion of the lower housing 12 interposed therebetween. As a result, the second balancer shaft first bearing portion 24 and the oil intake passage 31 are brought closer to each other to enhance heat transfer. The same can be said for the first balancer shaft 14 as well.

Further, as described above, the first balancer shaft 14 (see FIG. 2) and the second balancer shaft 20 (see FIG. 2) are arranged in parallel in the lower housing 12. , two rows of housing fixing bolt holes 36 are formed at intervals. Each row is formed from three housing fixing bolt holes 36, and the three housing fixing bolt holes 36 in each row are arranged at approximately equal intervals.

Here, the housing fixing bolt hole 36C in the middle of the row of housing fixing bolt holes 36 on the left end side is provided between the first balancer shaft second bearing portion 17 and the second balancer shaft second bearing portion 23. . Therefore, the housing fixing bolt hole 36</b>C in the middle of the row of housing fixing bolt holes 36 on the left end side is formed at a position included in the area inside the oil intake opening forming wall 35 . When the housing fixing bolt 08 is tightened, the housing fixing bolt 08 is exposed to the oil intake opening 29 as shown in FIG.

In this manner, the housing fixing bolts 08C can be arranged at approximately equal intervals with the other housing fixing bolts 08 inside the oil intake opening forming wall 35, and by tightening the housing fixing bolts 08, the upper housing 13 can be fixed with equal force.

Next, lubrication of the bearings in the balancer device 10 will be briefly described with reference to FIG. A part of the oil discharged from the oil pump 11 and lubricating the mechanical sliding parts of the internal combustion engine is introduced into the upper housing 13 of the balancer device 10 to lubricate the sliding parts such as bearings in the balancer device 10. An oil introduction passage is formed at least in the lower housing 12 so as to do so. Although there are various configurations of this oil introduction passage, the following configurations are known.

FIG. 8 shows the shape of the inner side of the lower housing 12. As shown in FIG. Inside the lower housing 12, there are provided first balancer shaft second bearing support portions for supporting first balancer shaft second bearing portions 17 and first balancer shaft first bearing portions 18 at both ends of the first balancer shaft 14. 37 and a first balancer shaft first bearing support portion 38 are formed.

Similarly, a second balancer shaft second bearing support portion 39 for supporting the second balancer shaft second bearing 23 and the second balancer shaft first bearing portion 24 at both ends of the second balancer shaft 20, and a second balancer shaft A first bearing support portion 40 is formed.

The oil returned from the internal combustion engine flows through the oil introduction passage 41 from the oil introduction opening 44 and branches into the first oil introduction passage 42 and the second oil introduction passage 43 .

The first oil introduction passage 42 flows to the first balancer shaft first bearing support portion 38 , then the oil that has passed through the first balancer shaft first bearing support portion 38 flows to the second balancer shaft first bearing support portion 40 . be guided. This lubricates the first balancer shaft first bearing portion 18 and further lubricates the second balancer shaft first bearing portion 24 .

Similarly, the second oil introduction passage 43 flows to the first balancer shaft second bearing support portion 37, and then the oil that has passed through the first balancer shaft second bearing support portion 37 flows into the second balancer shaft second bearing support portion 37. It is led to part 39. This lubricates the first balancer shaft second bearing portion 17 and further lubricates the second balancer shaft second bearing portion 23 .

Thus, the first oil introduction passage 42 of the lower housing 12 connects the oil introduction opening 44 and the second balancer shaft first bearing support 40, and the first balancer shaft first bearing support 38 is It is provided between the oil introduction opening portion 44 and the second balancer shaft first bearing support portion 40 .

Similarly, the second oil introduction passage 43 of the lower housing 12 connects the oil introduction opening 44 and the second balancer shaft second bearing support 39, and the first balancer shaft second bearing support 37 connects the oil It is provided between the introduction opening portion 44 and the second balancer shaft second bearing support portion 39 .

Next, the meshing state of the crank gear, balancer drive gear 15, reduction gear 21, and pump drive gear will be described. FIG. 9 is a cross section between the oil pump 11, the lower housing 12, and the upper housing 13, and virtually represents the engagement state of the crank gear, the balancer drive gear 15, the reduction gear 21, and the pump drive gear. there is

In FIG. 9, a crank gear 47 is arranged in a recess 46 formed in the center of the upper housing 13 . This crank gear 47 is rotated by the crankshaft of the internal combustion engine and transmits this rotation to the balancer drive gear 15 . Rotation of the balancer drive gear 15 is transmitted to the reduction gear 21 through the first balancer shaft 14, the first gear 16, the second gear 22, and the second balancer shaft 20, as shown in FIG. The rotation of the reduction gear 21 is transmitted to the pump driving gear 48 to rotate the pump shaft to perform the pump action.

Next, the arrangement and configuration of the oil suction passage 31 will be described with reference to FIGS. 10 to 12. FIG. 10 shows the AA section of FIG. 4, FIG. 11 shows the BB section of FIG. 4, and FIG. 12 shows the CC section of FIG. 10 to 12 are collectively described below.

As shown in FIG. 10 , the lower housing 12 and the upper housing 13 are firmly fixed to each other by housing fixing bolts 08 . Between the lower housing 12 and the upper housing 13, a first balancer shaft 14 and a second balancer shaft 20 are arranged parallel to each other with a predetermined distance therebetween so as to extend in a direction orthogonal to the plane of the drawing. there is 10, the first balancer shaft first bearing portion 18 and the second balancer shaft first bearing portion 24 are supported.

On the outer surface of the lower housing 12 opposite to the upper housing 13 when viewed in a plane orthogonal to the rotational axes of the first balancer shaft 14 and the second balancer shaft 20, an oil intake passage forming wall 34 and an oil inlet passage forming wall 34 are provided. A suction opening forming wall 35 is formed away from the outer surface of the lower housing 12 . Accordingly, the oil suction passage forming wall 34 and the oil suction opening forming wall 35 are shaped to protrude from the outer surface of the lower housing 12 .

10 to 12, the first balancer shaft 14 and the second balancer shaft 20 are supported by a first balancer shaft first bearing support portion 38 and a second balancer shaft first bearing support portion 40. ing. Therefore, metal for forming the lower housing 12 exists in this portion. Therefore, the heat generated in each bearing portion, particularly the first balancer shaft first bearing portion 18, is transferred to the oil flowing through the oil suction passage 31 in the oil suction passage forming wall 34 by transferring the heat through the metal. .

The oil intake passage forming wall 34 is formed between the outermost peripheral surface of the first balancer shaft 14 and the outermost peripheral surface of the second balancer shaft 20 in the first balancer shaft 14 and the second balancer shaft 20 arranged in parallel. It is arranged within the range of the arrangement region (Rgn).

However, depending on the physical size of the lower housing 12 and the shape of the oil suction passage forming wall 34, the oil suction passage forming wall 34 may be outside the range of the arrangement region (Rgn). In this case, in consideration of heat dissipation, it is advantageous in terms of heat dissipation effect to configure so that at least half of the oil intake passage 31 exists in the arrangement region (Rgn).

Furthermore, as can be seen from the drawings, an oil suction passage is provided on the outer surface of the lower housing 12 opposite to the upper housing 13 when viewed in a plane orthogonal to the rotation axes of the first balancer shaft 14 and the second balancer shaft 20. A forming wall 34 and an oil suction opening forming wall 35 are formed so as to be distant from the outer surface of the lower housing 12 .

The oil intake passage 31 is formed so as to overlap the second balancer shaft 20 when viewed from a plane perpendicular to the rotation axis. In other words, when the second balancer shaft 20 is projected onto the oil suction passage forming wall 34, the second balancer shaft 20 and the oil suction passage 31 are positioned to overlap each other.

Further, a specific description will be given with reference to FIG. 11 . As shown in FIG. 11, in a direction (OD) orthogonal to a virtual line (VL) connecting the rotation axes (O) of the first balancer shaft 14 and the second balancer shaft 20 arranged in parallel, the second balancer The shaft 20 and the oil suction passage forming wall 34 are determined to overlap each other when the oil suction passage forming wall 34 is viewed from the second balancer shaft 20 . Of course, the oil suction opening forming wall 35 also extends along the direction (OD) perpendicular to the virtual line (VL).

As a result, as can be seen from FIG. 7, it is possible to achieve the effect of improving the unity of the overall arrangement structure including the oil intake passage forming wall 34 . Here, when the oil suction port 26 of the oil pump 11 is arranged on the side of the first balancer shaft 14 , the first balancer shaft 14 and the oil suction passage forming wall 34 are arranged so that oil is sucked from the first balancer shaft 14 . When the passage forming wall 34 is viewed, they are in an overlapping positional relationship.

As can be seen from FIG. 3 , the second balancer shaft first bearing portion 18 and the second balancer shaft second bearing portion 17 are also formed so as to overlap with the oil intake passage 31 . In other words, when the second balancer shaft first bearing portion 18 and the second balancer shaft second bearing portion 17 are projected onto the oil suction passage forming wall 34, the second balancer shaft 20 and the oil suction passage 31 overlap each other. It is said that As a result, as can be seen from FIG. 7, it is possible to achieve the effect of improving the unity of the overall arrangement structure including the oil intake passage forming wall 34 .

When the balancer device 10 described above is attached to an internal combustion engine, the configuration is as shown in FIG. That is, as shown in FIG. 10 , the upper housing 13 is fixed to the lower surface of the cylinder block 04 between the oil pan 05 and the cylinder block 04 by the balancer fastening bolts 06 .

In this state, the tip end side of the oil suction opening forming wall 35 of the oil strainer 28 is immersed in the surface of lubricating oil stored in the oil pan 5 . When the oil pump 11 is driven to rotate in this state, as shown in FIG. . The inflowing oil is pressurized by the oil pump 11 and discharged toward the internal combustion engine.

As described above, according to the present invention, in the direction of the rotation axis of the balancer shaft housed in the housing, the first balancer shaft is provided at a position on the side of the balancer drive gear of the second balancer shaft and pivotally supports the balancer shaft. and a balancer shaft second bearing provided at a position on the opposite side of the balancer drive gear of the balancer shaft to support the balancer shaft, wherein at least the balancer shaft first bearing and the A suction opening of an oil strainer provided between the balancer shaft second bearing portion and open in a direction orthogonal to the rotation axis so as to allow the oil in the oil pan to be sucked, and along the balancer shaft from the oil suction opening. An oil suction passage of an oil strainer extends to be connected to the suction portion of the oil pump, and the oil suction opening of the oil strainer and the oil suction passage of the oil strainer are formed in the housing.

According to this, since the oil suction passage leading from the suction opening of the oil strainer to the oil pump is formed integrally with the housing, the oil flowing through the oil suction passage passes through the metal forming the housing to the first oil. The heat of the bearing portion of the balancer shaft can be removed efficiently. As a result, it is possible to suppress an increase in rattling noise between the crank gear and the balancer drive gear.

In addition, the present invention is not limited to the above-described embodiment, and includes various modifications. For example, the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described. Also, part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Moreover, it is possible to add, delete, or replace part of the configuration of each embodiment with another configuration.

REFERENCE SIGNS LIST 10 balancer device 11 oil pump 12 lower housing 13 upper housing 14 first balancer shaft 15 balancer drive gear 16 first gear 17 first balancer shaft second bearing Parts 18... First balancer shaft first bearing part 19... First balancer weight 20... Second balancer shaft 21... Reduction gear 22... Second gear 23... Second balancer shaft second bearing part 24 ... second balancer shaft first bearing portion 25 ... second balancer weight 26 ... pump suction port 27 ... oil discharge port 28 ... oil strainer 29 ... oil suction opening 31 ... oil suction passage 34 ... oil Intake passage forming wall 35 . . . Oil suction opening forming wall.

Claims (17)

A balancer device for an internal combustion engine, comprising at least an oil pump for sucking oil from an oil pan, and a balancer body to which the oil pump is attached and which is housed inside a housing space formed in a housing,
The balancer body includes a balancer shaft provided with a balancer drive gear that meshes with at least a crank gear of an internal combustion engine,
a balancer shaft first bearing provided at a position on the balancer drive gear side of the balancer shaft in the direction of the rotation axis of the balancer shaft housed in the housing and supporting the balancer shaft; a balancer shaft second bearing provided at a position on the opposite side of the balancer drive gear and pivotally supporting the balancer shaft;
It is provided between at least the balancer shaft first bearing portion and the balancer shaft second bearing portion in the direction of the rotation axis, and is opened in the direction orthogonal to the rotation axis so that oil in the oil pan can be sucked. and an oil suction passage of the oil strainer extending from the oil suction opening along the balancer shaft and connected to the suction portion of the oil pump, wherein the oil suction opening is and an oil intake passage are formed in the housing. It has at least an oil pump that draws in oil from an oil pan and supplies lubricating oil to the internal combustion engine, and a balancer main body to which the oil pump is attached and that is housed inside a housing space formed in a housing. A balancer device for an internal combustion engine,
The housing is
comprising an upper housing and a lower housing fixed to the upper housing and housing the balancer main body,
The balancer body includes a first rotation system and a second rotation system,
The first rotation system has a balancer drive gear fixed to one end thereof, which meshes with a crank gear rotated by the internal combustion engine, and a first gear fixed to the other end thereof, and is provided between the balancer drive gear and the first gear. a first balancer shaft having a first balancer weight provided in the first balancer shaft provided on the side of the balancer driving gear; a first bearing portion of the first balancer shaft provided on the side of the balancer drive gear; comprising a second bearing,
The second rotating system has one end fixed with a second gear that meshes with the first gear, and the other end with a reduction gear that meshes with the pump driving gear of the oil pump. a second balancer shaft having a second balancer weight provided between and in a parallel positional relationship with the first balancer shaft; a second balancer shaft first bearing portion provided on the side of the reduction gear; A second balancer shaft second bearing provided on the side of the second gear _,
provided at least between the first balancer shaft first bearing portion and the first balancer shaft second bearing portion in the direction of the rotation axes of the first balancer shaft and the second balancer shaft; In an orthogonal direction, an oil suction opening of an oil strainer that is open to allow the oil in the oil pan to be sucked in, and an oil suction opening extending from the oil suction opening along the first balancer shaft and connected to a suction portion of the oil pump. and an oil suction passage for the oil strainer, wherein the oil suction opening and the oil suction passage are formed in the lower housing. A balancer device for an internal combustion engine according to claim 2,
The oil intake passage is provided between an arrangement area connecting the outermost peripheral surface of the first balancer shaft and the outermost peripheral surface of the second balancer shaft when viewed from a plane orthogonal to the rotation axis. A balancer device for an internal combustion engine. A balancer device for an internal combustion engine according to claim 3,
A balancer device for an internal combustion engine, wherein more than half of the oil intake passage is provided in the arrangement area when viewed in a cross section orthogonal to the rotation axis. A balancer device for an internal combustion engine according to claim 3,
A balancer device for an internal combustion engine, wherein the oil intake passage is provided at a position overlapping with the second balancer shaft when viewed in a cross section orthogonal to the rotation axis. A balancer device for an internal combustion engine according to claim 3,
A balancer device for an internal combustion engine, wherein the oil intake passage is an elongated hole along the rotation axis of the second balancer shaft when viewed in a cross section orthogonal to the rotation axis. A balancer device for an internal combustion engine according to claim 2,
The lower housing pivotally supports the second balancer shaft first bearing portion and the second balancer shaft second bearing portion. A balancer device for an internal combustion engine, wherein the balancer device is provided at a position where the second balancer shaft first bearing portion and the second balancer shaft second bearing portion overlap each other. A balancer device for an internal combustion engine according to claim 7,
the lower housing pivotally supports the first balancer shaft first bearing portion and the first balancer shaft second lower bearing portion;
When the lower housing is viewed from the upper housing toward the lower housing, the oil intake opening is positioned so as to overlap the first balancer shaft second bearing portion and the second balancer shaft second bearing portion. A balancer device for an internal combustion engine, wherein a portion is formed, and the oil intake opening opens on the side opposite to the upper housing. A balancer device for an internal combustion engine according to claim 8,
When the lower housing is viewed from the lower housing toward the upper housing, a fastening member for fastening the upper housing and the lower housing is provided inside the oil suction opening. A balancer device for an internal combustion engine, characterized by: A balancer device according to claim 9,
A balancer device for an internal combustion engine, wherein the fastening member is provided between the first balancer shaft second bearing portion and the second balancer shaft second bearing portion. A balancer device for an internal combustion engine according to claim 2,
Oil from the internal combustion engine is introduced into the upper housing, and oil from the upper housing is guided to the second balancer shaft first bearing after passing through the first balancer shaft first bearing. A balancer device for an internal combustion engine, characterized by: A balancer device for an internal combustion engine according to claim 2,
The upper housing has an upper oil introduction opening through which oil that has passed through the internal combustion engine is introduced,
The lower housing has a lower oil introducing opening connected to the upper oil introducing opening, a lower oil introducing opening connected to the lower oil introducing opening, and a first bearing portion of the first balancer shaft and the second balancer. A balancer device for an internal combustion engine, comprising: an oil introduction passage connecting the shaft first bearings. A balancer device for an internal combustion engine according to claim 12,
In the oil introduction passage, the first balancer shaft first bearing portion is provided between the lower oil introduction opening and the second balancer shaft first bearing portion. balancer device. A balancer device for an internal combustion engine according to claim 2,
An oil suction opening forming wall forming the oil suction opening and an oil suction passage forming wall forming the oil suction passage are integrally and inseparably formed with the lower housing. Device. A balancer device for an internal combustion engine according to claim 14,
A balancer device for an internal combustion engine, wherein the oil suction opening forming wall and the oil suction passage forming wall are formed to protrude from the outer surface of the lower housing. A balancer device for an internal combustion engine according to claim 15,
In a direction perpendicular to an imaginary line connecting the rotation axes of the first balancer shaft and the second balancer shaft arranged in parallel, the second balancer shaft and the oil intake passage forming wall A balancer device for an internal combustion engine, wherein the balancer device for an internal combustion engine is determined to overlap when the oil intake passage forming wall is viewed from the shaft. An oil pan fixed to a cylinder block, an oil pump housed inside the oil pan that sucks and discharges lubricating oil from the oil pan, and an oil pump housed inside the oil pan to which the oil pump is attached. and a balancer device fixed to the cylinder block by
The balancer device is the balancer device according to any one of claims 1 to 16, and the oil suction opening of the oil strainer of the balancer device is adapted to the lubricating oil stored in the oil pan. An internal combustion engine characterized by being submerged.

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