JP7412463B2 - internal combustion engine - Google Patents

Description

The present invention relates to internal combustion engines.

BACKGROUND ART Conventionally, an internal combustion engine is known in which an oil pump is driven by rotation of a balance shaft.

Japanese Patent Application Publication No. 2014-88807

In this type of internal combustion engine, it is beneficial if oil can be efficiently supplied to the oil supply target.

The present invention has been made in view of the above, and one object of the present invention is to enable oil to be efficiently supplied to an oil supply target in an internal combustion engine.

In order to solve the above-mentioned problems and achieve the objects, an internal combustion engine according to the present invention includes a balance shaft, which is a separate part from the balance shaft, which is connected to the balance shaft by fitting, and which is a separate part from the balance shaft. A rotary shaft that rotates integrally, a cover having a hole into which the rotary shaft is inserted, an oil pump driven by the rotary shaft, and a connecting portion from the cover to the balance shaft and the rotary shaft. a guide portion that protrudes to the side and guides oil falling from an oil hole located above the joint portion to the joint portion , and the rotating shaft and the oil hole are arranged in a direction perpendicular to a vertical direction. The guide portion extends from the oil hole side toward the rotating shaft .

According to such a configuration, the oil falling from the oil hole can be supplied to the joint, so that oil can be efficiently supplied to the joint. Furthermore, even if the oil hole and the rotating shaft are vertically misaligned, the oil that falls from the oil hole can be smoothly supplied to the coupling portion by the guide portion.

In the internal combustion engine, for example, the guide portion extends from the oil hole side toward the rotating shaft at an angle with respect to the vertical direction.

According to this configuration, the oil that has fallen from the oil hole to the guide part can flow down along the slope of the guide part, so that the oil that has fallen from the oil hole can be smoothly supplied to the joint part by the guide part. Can be done.

According to the present invention, oil can be efficiently supplied to an oil supply target in an internal combustion engine.

FIG. 1 is a sectional view showing a part of an internal combustion engine according to an embodiment. FIG. 2 is a cross-sectional perspective view showing a part of the internal combustion engine of the embodiment. FIG. 3 is a cross-sectional perspective view showing a part of the internal combustion engine of the embodiment. FIG. 4 is a perspective view showing the pump cover in the internal combustion engine of the embodiment.

Embodiments will be described below with reference to FIGS. 1 to 4. Note that, in this specification, a constituent element according to an embodiment and a description of the element may be described using a plurality of expressions. The components and their descriptions are examples and are not limited by the language in this specification. Components may also be identified by different names than herein. Also, components may be described using language that differs from that used herein.

FIG. 1 is a sectional view showing a part of an internal combustion engine 10 according to an embodiment. FIG. 2 is a cross-sectional perspective view showing a part of the internal combustion engine 10 of the embodiment. FIG. 3 is a cross-sectional perspective view showing a part of the internal combustion engine 10 of the embodiment. The internal combustion engine 10 is, for example, a reciprocating engine mounted on a vehicle. Note that the internal combustion engine 10 may be another type of internal combustion engine or may be installed in another device.

As shown in the drawings, the X, Y, and Z axes are defined herein for convenience. The X-axis, Y-axis, and Z-axis are orthogonal to each other. The X-axis is provided along the width of the vehicle. A Y-axis is provided along the length of the vehicle. The Z-axis is provided along the height of the vehicle.

Additionally, the X direction, Y direction and Z direction are defined herein. The X direction is a direction along the X axis, and includes a +X direction indicated by an arrow on the X axis, and a -X direction opposite to the arrow on the X axis. The Y direction is a direction along the Y axis, and includes a +Y direction indicated by an arrow on the Y axis and a -Y direction which is the opposite direction to the arrow on the Y axis. The Z direction is a direction along the Z axis, and includes a +Z direction indicated by an arrow on the Z axis and a -Z direction opposite to the arrow on the Z axis.

In the following description, the +Z direction is defined as a vertically upward direction, and the -Z direction is defined as a vertically downward direction. Note that the Z direction may be different from the vertical direction depending on various conditions such as the location where the vehicle is located and the condition of the tires.

Internal combustion engine 10 includes a crankcase 11, a chain cover 12, a balance shaft 13, an oil pump 14, a rotating shaft 15, a first bearing 16, and a second bearing 17. Note that the internal combustion engine 10 includes a cylinder block, an oil pan, a crankshaft, a chain, and the like in addition to the above.

Crankcase 11 has an outer surface 11a. Further, the crankcase 11 is provided with an internal space 11b that is open to the outer surface 11a. Further, the crankcase 11 is provided with a support portion 11c that supports the first bearing. Furthermore, an oil hole 51 is provided on the outer surface 11a of the crankcase 11. Oil circulating in the internal combustion engine 10 flows out from the oil hole 51 due to the operation of the oil pump 14. For example, oil that has passed through the cylinder head flows out from the oil hole 51.

The chain cover 12 is placed over the outer surface 11a of the crankcase 11. The chain cover 12 is fixed to the crankcase 11 with a coupling member 22 (FIG. 2) such as a bolt. The chain cover 12 covers a chain (not shown) located between the crankcase 11 and the chain cover 12. The inner surface 12a of the chain cover 12 is provided with a recess 12b. The recess 12b is open to the inner surface 12a. Furthermore, the chain cover 12 is provided with a bottomed hole 12c. The hole 12c opens at the bottom of the recess 12b. A second bearing 17 is provided on a peripheral surface 12d forming a hole 12c in the chain cover 12. The second bearing 17 is a sliding bearing. That is, the second bearing 17 is constituted by a part of the circumferential surface 12d.

At least a portion of the balance shaft 13 is housed inside the crankcase 11. The balance shaft 13 is rotatably supported around the rotation center axis Ax by two bearings (one bearing is not shown) including the first bearing 16. One end 13a of the balance shaft 13 is rotatably supported by a first bearing 16. Hereinafter, unless otherwise specified, the axial direction, radial direction, and circumferential direction refer to the axial direction, radial direction, and circumferential direction of the rotation center axis Ax.

The first bearing 16 is a rolling bearing and includes an outer ring 16a, an inner ring 16b, and rolling elements 16c.

The rotating shaft 15 has one end 15a and the other end 15b. The rotating shaft 15 has a large diameter portion 15c and a small diameter portion 15d. The large diameter portion 15c includes one end portion 15a. The small diameter portion 15d includes the other end 15b and has a smaller diameter than the large diameter portion 15c.

The rotating shaft 15 is coupled to the balance shaft 13 by fitting, and rotates together with the balance shaft 13 around the rotation center axis Ax.

Specifically, the rotating shaft 15 and the balance shaft 13 are spline-coupled. The large diameter portion 15c of the rotating shaft 15 is provided with a male spline portion 15e. The male spline portion 15e is composed of external teeth. On the other hand, a hole 13b is provided in one end 13a of the balance shaft 13, and a female spline portion 13d is provided in a surface 13c of the balance shaft 13 that forms the hole 13b. The female spline portion 13d is composed of internal teeth. The large diameter portion 15c of the rotating shaft 15 is inserted into the hole 13b of the balance shaft 13, and the male spline portion 15e and the female spline portion 13d are engaged with each other. The male spline portion 15e and the female spline portion 13d constitute a connecting portion 21 between the balance shaft 13 and the rotating shaft 15. The coupling portion 21 is also referred to as a spline coupling portion.

The oil pump 14 is, for example, a trochoid oil pump, and includes a casing 31, an outer rotor 32, and an inner rotor 33. As the inner rotor 33 rotates, the oil pump 14 sucks oil stored in an oil pan through a suction port, and discharges the sucked oil from a discharge port. Oil discharged from the oil pump 14 is supplied to each part of the internal combustion engine 10 via passages and the like. The oil supplied to each part falls under the action of gravity and returns to the oil pan.

The casing 31 includes a base portion 34 provided on the chain cover 12 and a pump cover 35. The base portion 34 is a portion of the chain cover 12 that includes the recess 12b, and is integrally formed with the chain cover 12. That is, a part of the chain cover 12 constitutes the base portion 34.

The pump cover 35 is fixed to the chain cover 12 with a coupling member 23 such as a screw while covering the recess 12b. The pump cover 35 is fixed to the crankcase 11 via the chain cover 12, and is not directly fixed to the crankcase 11.

The pump cover 35 has one side 35a and the other side 35b. One surface 35a is overlapped with the inner surface 12a of the chain cover 12. Further, the pump cover 35 is provided with a hole 35c. The hole 35c passes through the pump cover 35 in the thickness direction of the pump cover 35. That is, the hole 35c is open on one side 35a and the other side 35b. The small diameter portion 15d of the rotating shaft 15 is inserted into the hole 35c. The circumferential surface 35d forming the hole 35c in the pump cover 35 and the outer circumferential surface 15f of the rotating shaft 15 are spaced apart, and there is a gap between the circumferential surface 35d of the pump cover 35 and the outer circumferential surface 15f of the rotating shaft 15. Sa is formed.

The outer rotor 32 has a plurality of recesses formed in a trochoidal curve or the like. The inner rotor 33 has one less convex portion than the concave portions of the outer rotor 32, is disposed inside the outer rotor 32, and meshes with the outer rotor 32. A hole 33a is formed in the inner rotor 33. The hole 33a passes through the inner rotor 33 in the axial direction. The small diameter portion 15d of the rotating shaft 15 is press-fitted into the hole 33a. That is, the inner rotor 33 rotates together with the rotation shaft 15 and the balance shaft 13 around the rotation center axis Ax. The inner rotor 33 rotates while the tip of the convex portion slides on the inner surface of the concave portion of the outer rotor 32. As a result, oil is sucked and discharged. Note that the oil pump 14 is not limited to the above configuration.

FIG. 4 is a perspective view showing a pump cover in the internal combustion engine 10 of the embodiment. Two guide portions 36 and 37 are provided on the other surface 35b of the pump cover 35. The guide portion 36 protrudes from the pump cover 35 toward the connecting portion 21 between the balance shaft 13 and the rotating shaft 15. The guide portion 36 is provided below the rotating shaft 15. The guide portion 36 is located closer to the inner ring 14b of the outer ring 14a and the inner ring 14b of the first bearing 16, and faces the first bearing 16 in the axial direction. The guide portion 36 is spaced apart from between the outer ring 14a and the inner ring 14b of the first bearing 16. The guide portion 36 is located closer to the inner ring 14b between the outer ring 14a and the inner ring 14b, and faces the first bearing 16 in the axial direction. The guide portion 36 is an arcuate rib. The arc of the guide portion 36 extends along the circumferential direction of the first bearing 16 . The guide portion 36 guides oil from the oil pump 14 leaking from the gap Sa between the circumferential surface 35 d of the pump cover 35 and the outer circumferential surface 15 f of the rotary shaft 15 to the first bearing 16 .

The guide portion 37 is provided above the rotating shaft 15. The guide portion 36 protrudes from the pump cover 35 toward the connecting portion 21 between the balance shaft 13 and the rotating shaft 15. The guide portion 37 is located offset from the oil hole 51 (FIG. 2) in a direction perpendicular to the vertical direction, and extends from the oil hole 51 side toward the rotating shaft 15. The guide portion 37 is a flat rib that extends from the oil hole 51 side toward the rotating shaft 15 while being inclined with respect to the vertical direction (Z direction). The guide portion 37 guides oil falling from the oil hole 51 located above the joint portion 21 to the joint portion 21 . A portion of the oil that has fallen from the guide section 37 falls onto the guide section 37 and is supplied from the guide section 37 to the first bearing 16 .

In the internal combustion engine 10 having the above configuration, the rotary shaft 15 rotates as the balance shaft 13 rotates, and an oil pump driving method is performed in which the oil pump 14 is driven by the rotation of the rotary shaft 15.

As described above, in the present embodiment, the internal combustion engine 10 includes the balance shaft 13, the rotary shaft 15, the oil pump 14, and the guide section 37. The rotary shaft 15 is a separate component from the balance shaft 13. It is connected to the balance shaft 13 by fitting and rotates together with the balance shaft 13. The oil pump 14 has a pump cover 35 (cover) in which a hole 35c into which the rotating shaft 15 is inserted is formed, and is driven by the rotating shaft 15. The guide portion 37 protrudes from the pump cover 35 toward the joint portion 21 between the balance shaft 13 and the rotating shaft 15, and guides oil falling from the oil hole 51 located above the joint portion 21 to the joint portion 21.

According to such a configuration, the oil falling from the oil hole 51 can be supplied to the joint part 21, so that oil can be smoothly supplied to the joint part 21. Therefore, the frictional force generated in the coupling portion 21, the rotating shaft 15, and the balance shaft 13 can be suppressed. Therefore, it is possible to improve fuel efficiency.

Furthermore, the rotating shaft 15 and the oil hole 51 are positioned offset in a direction orthogonal to the vertical direction, and the guide portion 37 extends from the oil hole 51 side toward the rotating shaft 15.

According to such a configuration, even if the oil hole 51 and the rotating shaft 15 are deviated from each other in a direction perpendicular to the vertical direction, the oil falling from the oil hole 51 can be smoothly supplied to the coupling portion 21 by the guide portion 37. Can be done.

Further, the guide portion 37 extends from the oil hole 51 side toward the rotating shaft 15 at an angle with respect to the vertical direction.

According to this configuration, the oil that has fallen from the oil hole 51 to the guide section 37 can flow down along the slope of the guide section 37, so that the oil that has fallen from the oil hole 51 can be smoothly combined by the guide section 37. 21.

In addition, although the example in which the guide part 36 was spaced apart from between the outer ring 14a and the inner ring 14b of the 1st bearing 16 was shown in the said embodiment, it is not limited to this. For example, the tip of the guide portion 36 may be located between the outer ring 14a and the inner ring 14b of the first bearing 16.

The embodiments of the present invention described above do not limit the scope of the invention, but are merely examples included within the scope of the invention. An embodiment of the present invention includes changes, omissions, and at least some of the specific uses, structures, shapes, actions, and effects of the above-described embodiments without departing from the gist of the invention. It may be one that has been added.

DESCRIPTION OF SYMBOLS 10... Internal combustion engine, 13... Balance shaft, 14... Oil pump, 15... Rotating shaft, 16... First bearing (bearing), 35... Pump cover (cover), 35c... Hole, 35d... Surrounding surface, 37... Guide Part, 51...Oil hole, Sa...Gap.

Claims (2)

balance shaft and
a rotating shaft that is a separate part from the balance shaft, is coupled to the balance shaft by fitting, and rotates together with the balance shaft;
an oil pump having a cover formed with a hole into which the rotating shaft is inserted, and driven by the rotating shaft;
a guide part that protrudes from the cover toward the joint between the balance shaft and the rotating shaft and guides oil falling from an oil hole located above the joint to the joint;
Equipped with
The rotating shaft and the oil hole are positioned offset in a direction perpendicular to a vertical direction,
In the internal combustion engine, the guide portion extends from the oil hole side toward the rotating shaft . The guide portion is inclined with respect to the vertical direction and extends from the oil hole side toward the rotating shaft.
The internal combustion engine according to claim 1 .

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