JP6965702B2 - Oil supply mechanism - Google Patents

Description

The present disclosure relates to an oil supply mechanism that supplies oil into the cylinder of an engine.

In the cylinder of the engine, the piston slides along the inner surface of the cylinder. Therefore, the engine is provided with a mechanism or the like for supplying oil to the inner surface of the cylinder. For example, as a mechanism for supplying oil to the inner surface of a cylinder, there is a mechanism in which an oil passage leading to a crankpin is formed in a crankshaft and abundant oil is supplied to this oil passage. According to such a mechanism, the oil after lubricating the crankpin can be flipped up by the rotation of the crankshaft and supplied to the inner surface of the cylinder.

Japanese Unexamined Patent Publication No. 2016-217501 Japanese Unexamined Patent Publication No. 2013-79630 Japanese Unexamined Patent Publication No. 2006-29523

However, it is possible that a mechanism that flips up oil by the rotation of the crankshaft may not be able to supply a sufficient amount of oil to the inner surface of the cylinder.

Therefore, the present disclosure was devised in view of such circumstances, and an object thereof is to provide an oil supply mechanism capable of increasing the amount of oil supplied to the inner surface of the cylinder.

According to one aspect of the invention
An oil groove formed on the inner surface of the crank web that overlaps the large end of the connecting rod in an annular shape coaxial with the crank pin and receives oil from the crank pin.
An oil ejection hole formed in the crank web and for ejecting the oil in the oil groove toward the inner surface of the cylinder.
It is provided with a protrusion provided at the large end and projected into the oil groove.
An oil supply mechanism is provided in which the protrusion is arranged so as to approach the inlet of the oil ejection hole when the outlet of the oil ejection hole faces the direction of the cylinder.

Preferably, the oil ejection hole is formed at the tip of the crank web.

Preferably, the inlet of the oil ejection hole is formed on the outer peripheral surface of the oil groove.

Preferably, the inlet portion of the oil ejection hole is inclined in a direction opposite to the rotation direction of the crank web.

Further, a throttle portion for narrowing the flow path may be formed at the outlet of the oil ejection hole.

Further, the oil groove may be provided with a gate member that blocks the oil groove so as to increase the pressure in the oil ejection hole so as to be openable and closable.

According to the present disclosure, the amount of oil supplied to the inner surface of the cylinder can be increased.

It is a schematic diagram of the main part of the engine to which the oil supply mechanism which concerns on one Embodiment of this invention is applied. It is sectional drawing of the main part of a crankshaft and a connecting rod. It is a front view of a connecting rod. It is a perspective view of the main part of a connecting rod. FIG. 2 is a cross-sectional view taken along the line AA of FIG. It is a front sectional view explaining operation of an oil supply mechanism. It is a front sectional view explaining operation of an oil supply mechanism. It is a front sectional view explaining operation of an oil supply mechanism. It is an enlarged view of the main part of the oil supply mechanism which shows the other embodiment. It is an enlarged view of the main part of the oil supply mechanism which shows the other embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the embodiment described later, for convenience of explanation, the moving direction of the piston during the compression stroke is upward, and the opposite direction is downward. Further, the left side of the paper surface in FIG. 1 is the front side, and the right side of the paper surface is the rear side.

FIG. 1 is a schematic view of a main part of an engine to which the oil supply mechanism according to the present embodiment is applied. FIG. 2 is a cross-sectional view of a crankshaft and a connecting rod showing an oil supply mechanism, and shows a state of top dead center. The engine (internal combustion engine) E is a multi-cylinder compression ignition type internal combustion engine mounted on a vehicle, that is, a diesel engine. The illustrated example shows an in-line 4-cylinder engine, but the cylinder arrangement type, the number of cylinders, and the like of the engine are arbitrary. Further, the engine E may be a gasoline engine.

First, an engine to which the oil supply mechanism according to the present embodiment is applied will be described.

The engine E has a cylinder block 2 in which a cylinder 1 is formed, a crankshaft 4 rotatably supported by the cylinder block 2 via a journal bearing 3, and a rotatably lower end portion of a crankpin 5 of the crankshaft 4. A connecting rod 6 to be connected and a piston 7 rotatably connected to the upper end of the connecting rod 6 and housed in the cylinder 1 are provided.

The crankshaft 4 includes a plurality of journals 8 rotatably supported by the journal bearing 3 and arranged at intervals in the axial direction, and a crankweb 9 extending radially at the end of each journal 8. A crank pin 5 provided between the opposing crank webs 9 eccentrically with respect to the journal 8 and a counter weight 10 provided on the crank web 9 extending in the direction opposite to the crank web 9.

The connecting rod 6 has a large end 11 formed at the lower end and rotatably connected to the crankpin 5, a small end 12 formed at the upper end and rotatably connected to the piston 7, and a large end 11. And a rod-shaped rod main body portion 13 formed between the small end portions 12.

The cylinder block 2 constitutes the outer shell of the engine E. A main gallery 14 is formed in the cylinder block 2, and a first oil passage 15 for supplying oil from the main gallery 14 to the journal bearing 3 is formed in the cylinder block 2. A pump P is connected to the main gallery 14. The pump P supplies the oil from the oil pan 16 to the main gallery 14, and is driven by the power from the crankshaft 4. The pump P may be driven by a driving device such as a motor.

The crankshaft 4 is formed with a second oil passage 17 for guiding the oil from the first oil passage 15 to the crank pin 5.

Next, the oil supply mechanism according to this embodiment will be described.

As shown in FIGS. 2 and 3, the oil supply mechanism 18 is formed in an oil groove 19 formed in the crank web 9 of the crankshaft 4 to receive oil from the crank pin 5 and in the oil groove 19 formed in the crank web 9. It includes an oil ejection hole 20 for ejecting oil toward the inner surface of the cylinder 1 (see FIG. 1), and a protrusion 21 provided at the large end 11 of the connecting rod 6 and projected into the oil groove 19.

The oil groove 19 is formed on the inner side surface 9a of the crank web 9 that overlaps with the large end portion 11, and is formed in an annular shape coaxial with the crank pin 5. Further, the oil groove 19 is formed to have a rectangular cross section. The cross-sectional shape of the oil groove 19 is not limited to this. For example, the oil groove 19 may be formed in a semicircular cross section.

As shown in FIGS. 2 and 5, the oil ejection hole 20 is formed in the tip portion 9b of the crank web 9. Here, the tip portion 9b of the crank web 9 means a portion of the crank web 9 facing the crank pin 5 where the distance from the rotation center of the journal 8 is farther than the center of the crank pin 5. Further, the inlet 20a of the oil ejection hole 20 is formed in the oil groove 19 of the crank web tip portion 9b and is formed on the outer peripheral surface 19a of the oil groove 19. In particular, the inlet portion 20b of the oil ejection hole 20, that is, the oil ejection hole 20 of the portion branched from the oil groove 19, is inclined in a direction opposite to the rotation direction R of the crank web 9. As a result, the oil ejection hole 20 is inclined in the rotation direction of the protrusion 21 that rotates relative to the oil groove 19. Therefore, the oil pushed by the protrusion 21 is efficiently ejected from the oil ejection hole 20 to the outside of the crank web 9. Further, the outlet 20c of the oil ejection hole 20 is formed by opening on the outer surface of the tip end portion of the crank web 9. The oil ejection hole 20 is shown to extend in the same direction as the inlet portion 20b, but the oil ejection hole 20 is not limited to this. The oil ejection hole 20 downstream of the inlet portion 20b may extend in a direction different from that of the inlet portion 20b.

As shown in FIGS. 4 and 5, the protrusion 21 is for pushing the oil in the oil groove 19 in the circumferential direction of the oil groove 19, and is projected from the large end 11 in the axial direction of the crank pin 5. NS. Further, the protrusion 21 is formed in a columnar shape that is loosely fitted in the oil groove 19. The protrusion 21 is approached to the outer peripheral surface 19a, the inner peripheral surface 19b, and the bottom surface 19c of the oil groove 19 with a minute gap, and partitions the inside of the oil groove 19 in the circumferential direction. Further, in particular, the protrusion 21 is arranged so that the outlet 20c of the oil ejection hole 20 approaches the inlet 20a of the oil ejection hole 20 when the outlet 20c is directed toward the cylinder 1, that is, upward.

The operation of this embodiment will be described.

FIG. 5 is a cross-sectional view taken along the line AA of FIG. 2, showing the positional relationship between the protrusion 21 and the oil ejection hole 20 at top dead center. FIG. 6 shows a state in which the crankshaft 4 is rotated by 90 ° from the state of FIG. FIG. 7 shows a state in which the crankshaft 4 is rotated by 180 ° from the state of FIG. FIG. 8 shows a state immediately before the top dead center where the crankshaft is further rotated by an angle of less than 90 ° from the state of FIG. 7 and the protrusion 21 is brought close to the inlet 20a of the oil ejection hole 20.

As shown in FIG. 1, when the crankshaft 4 is rotated, the pump P is driven. The pump P sucks oil from the oil pan 16 and supplies the oil to the main gallery 14. The oil supplied to the main gallery 14 is supplied to the surface of the crankpin 5 via the first oil passage 15, the journal bearing 3, and the second oil passage 17. As shown in FIG. 2, the oil is continuously and abundantly supplied from the second oil passage 17 to the surface of the crank pin 5, spreads over the entire circumference of the crank pin 5, and flows toward both ends of the crank pin 5. As a result, the space between the crankpin 5 and the large end portion 11 is lubricated. The oil that reaches both ends of the crank pin 5 spreads radially outward of the crank pin 5 along the gap between the crank web 9 and the large end portion 11. As a result, the oil spreads between the crank web 9 and the large end portion 11 and collects in the oil groove 19. Then, a small part of the oil accumulated in the oil groove 19 overflows outward in the radial direction and spreads between the crank web 9 and the large end portion 11 on the outer peripheral side of the oil groove 19.

Further, as shown in FIGS. 5 and 6, the crankshaft 4 is rotated, so that the crankpin 5 is rotated around the journal 8. As a result, the oil groove 19 arranged coaxially with the crank pin 5 is also rotated around the journal 8.

In the connecting rod 6, the movement direction of the small end portion 12 is regulated only in the vertical direction by the piston 7 and the cylinder 1. Therefore, the connecting rod 6 maintains an upright posture while being rotated around the journal 8 on the large end 11 side. As a result, the large end portion 11 is rotated relative to the crank pin 5 and the crank web 9, and the protrusion 21 provided on the large end portion 11 is also formed in the oil groove 19 formed in the crank web 9. On the other hand, it is relatively rotated along its circumferential direction.

The protrusion 21 rotates relative to the oil groove 19 to push the oil forward in the rotation direction. At this time, the oil is continuously and abundantly supplied into the oil groove 19. The oil has a relatively high viscosity, and the protrusion 21 is rotated relative to the oil groove 19 at a relatively high speed. Therefore, the oil in front of the protrusion 21 in the rotation direction has a higher pressure than the oil in the rear in the rotation direction.

As shown in FIGS. 7 and 8, when the protrusion 21 approaches the inlet 20a of the oil ejection hole 20 in this state, the oil pressure at the inlet 20a of the oil ejection hole 20 rapidly rises, and the outlet 20c of the oil ejection hole 20 A relatively large amount of oil is spouted vigorously from. At this time, since the inlet portion 20b of the oil ejection hole 20 is inclined in the direction opposite to the rotation direction of the crank web 9, the oil is ejected from the oil groove 19 at a shallow angle with respect to the direction pushed by the protrusion 21. Branched into hole 20. Therefore, the oil pushed by the protrusion 21 is smoothly introduced into the oil ejection hole 20. Further, as shown in FIG. 8, the oil ejection hole 20 is in a posture in which the outlet 20c is directed upward, and the piston 7 is near the top dead center. Therefore, the oil ejected from the outlet 20c of the oil ejection hole 20 flies upward and is abundantly supplied to the inner surface of the cylinder 1 below the piston 7.

After that, when the protrusion 21 passes through the inlet 20a of the oil ejection hole 20, the oil pressure at the oil ejection hole inlet 20a drops sharply, and the oil ejection temporarily stops or decreases.

After that, every time the piston 7 approaches the top dead center, a large amount of oil is vigorously ejected from the outlet 20c of the oil ejection hole 20, and at other timings, the oil ejection from the outlet 20c of the oil ejection hole 20 is stopped or decreased. The operation of being done is repeated.

As described above, the oil supply mechanism 18 has an oil groove 19 formed in the crank web 9 in an annular shape to receive the oil from the crank pin 5, and an oil groove 19 formed in the crank web 9 to direct the oil in the oil groove 19 toward the inner surface of the cylinder 1. The oil ejection hole 20 for ejecting the oil and the protrusion 21 provided in the large end portion 11 and projecting into the oil groove 19 are provided, and the protrusion 21 has the outlet 20c of the oil ejection hole 20 in the direction of the cylinder 1. When facing, it is arranged so as to approach the inlet 20a of the oil ejection hole 20. Therefore, the oil supplied into the oil groove 19 can be ejected from the oil ejection hole 20 toward the cylinder 1 in synchronization with the rotation of the crankshaft 4, and the amount of oil supplied into the cylinder 1 can be increased. Can be done.

Further, the oil ejection hole 20 is formed in the tip portion 9b of the crank web 9. Therefore, when the piston 7 is located near the top dead center, the oil can be ejected from the oil ejection hole 20, and the oil can be reliably supplied to the inner surface of the cylinder 1.

Further, the inlet 20a of the oil ejection hole 20 is formed on the outer peripheral surface 19a of the oil groove 19. Therefore, the oil that receives the centrifugal force due to the rotation of the crank web 9 can be easily ejected from the oil ejection hole 20.

Further, the inlet portion 20b of the oil ejection hole 20 is inclined in a direction opposite to the rotation direction of the crank web 9. Therefore, the direction of the inlet portion 20b of the oil ejection hole 20 can be brought closer to the direction in which the protrusion 21 pushes the oil, and the oil in the oil groove 19 can be smoothly guided into the oil ejection hole 20.

Although the embodiments of the present invention have been described in detail above, the present invention can also have other embodiments as follows.

(1) As shown in FIG. 9, a throttle portion 30 for narrowing the flow path may be formed at the outlet 20c of the oil ejection hole 20. According to this, the momentum of the oil ejected from the oil ejection hole 20 can be strengthened, and the oil can be more reliably reached on the inner surface of the cylinder 1.

(2) As shown in FIG. 10, the oil groove 19 may be provided with a gate member 31 that blocks the oil groove 19 so as to increase the pressure in the oil ejection hole 20 so as to be openable and closable. In this case, the gate member 31 may be arranged in the oil groove 19 on the relative rotation direction side of the protrusion 21 from the inlet 20a of the oil ejection hole 20. Further, the gate member 31 may be pivotally supported by the crank web 9 for partitioning the oil groove 19 so as to be tilted in the relative rotation direction side of the protrusion 21. The crank web 9 that partitions the oil groove 19 may be provided with a spring 32 that urges the gate member 31 in the upright direction, that is, in the direction that closes the oil groove 19.

Further, it is preferable that the crank web 9 is formed with a recess 33 for accommodating the fallen gate member 31 and allowing the protrusion to pass through. Further, the spring 32 may be set to a spring strength such that the gate member 31 does not fall under the pressure when the protrusion 21 overlaps the position of the oil ejection hole 20. According to this, the pressure forward in the relative rotation direction can be continuously increased until the protrusion 21 overlaps the position of the oil ejection hole 20, and the momentum of the oil ejected from the oil ejection hole 20 can be strengthened. Then, the oil can be more reliably reached on the inner surface of the cylinder 1. Further, after the protrusion 21 exceeds the position of the oil ejection hole 20, the protrusion 21 hits the gate member 31, or the pressure in front of the protrusion 21 in the relative movement direction acts on the gate member 31, and the gate member 31 Opens.

The configurations of each of the above embodiments can be combined partially or wholly, unless otherwise inconsistent. The embodiment of the present invention is not limited to the above-described embodiment, and all modifications, applications, and equivalents included in the idea of the present invention defined by the claims are included in the present invention. Therefore, the present invention should not be construed in a limited manner and can be applied to any other technique belonging within the scope of the idea of the present invention.

1 Cylinder 5 Crankpin 6 Connecting rod 9 Crank web 9a Inner side surface 11 Large end 18 Oil supply mechanism 19 Oil groove 20 Oil ejection hole 20a Inlet 20c Outlet 21 Protrusion

Claims (6)

An oil groove formed on the inner surface of the crank web that overlaps the large end of the connecting rod in a ring shape coaxial with the crank pin and receives oil from the crank pin.
An oil ejection hole formed in the crank web and for ejecting the oil in the oil groove toward the cylinder,
It is provided with a protrusion provided at the large end and projected into the oil groove.
The oil supply mechanism is characterized in that the protrusion is arranged so as to approach the inlet of the oil ejection hole when the outlet of the oil ejection hole faces the direction of the cylinder. The oil ejection hole was formed at the tip of the crank web.
The oil supply mechanism according to claim 1. The oil supply device according to claim 1 or 2, wherein the inlet of the oil ejection hole is formed on the outer peripheral surface of the oil groove. The oil supply mechanism according to any one of claims 1 to 3, wherein the inlet portion of the oil ejection hole is inclined in a direction opposite to the rotation direction of the crank web. The oil supply mechanism according to any one of claims 1 to 4, wherein a throttle portion for narrowing the flow path is formed at the outlet of the oil ejection hole. The oil supply according to any one of claims 1 to 5, wherein a gate member for blocking the oil groove is provided in the oil groove so as to increase the pressure in the oil ejection hole so as to be openable and closable. mechanism.

Images