JP2000104725A - Lubrication structure of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lubricating structure of internal-combustion engines that can prevent abrasion or wear of end-side connecting rod bearings and thus suppress vibration and noise without causing increases in weight and in friction loss. SOLUTION: An end-side crank journal 21a has an internal oil hole 27. Another oil hole 28 opens at one end onto one end of the oil hole 27 and at the other end onto the periphery of a crankpin 23. An end-side journal bearing 24a has an arcuately sectioned groove 29 cut along the internal surface of an upper bearing part 24U to open on an oil feed passage 25. The oil feed passage 25, oil holes 27 and 28 and groove 29 cooperate to feed lubricating oil to an end-side connecting rod bearing 26a without interruption. An intermittent lubricating means consists of the oil feed passage 25, and an oil hole passing through the crank arm that exists between a crank journal other than such end-side ones and the crankpin 23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubrication structure for an internal combustion engine, and more particularly to a lubrication structure for a crankshaft.

[0002]

2. Description of the Related Art Generally, a pulley is mounted on one end (front end) and a flywheel is mounted on the other end (rear end) of a crankshaft of a vehicle-mounted internal combustion engine. However, due to the resonance of the pulley and the flywheel, the runout of the crankshaft increases at the end. Therefore,
When the cylinder at the end explodes, the fluctuation of the crankpin of that cylinder is larger than the fluctuation of the crankpin of the cylinders other than the end, and the load applied to the connecting rod bearing is changed to that of the other cylinder. It is larger and more prone to wear and more prone to vibration and noise.

[0003] Many proposals have been made to solve such a problem. For example, the one in which the diameter of the crank journal at the end is made larger than the diameter of the other crank journals to increase the rigidity (actually-open flat tire). Japanese Unexamined Patent Publication No. 3-55941) and those in which the thickness of a crank arm at the end is made greater than the thickness of the other crank arms to increase rigidity (see Japanese Utility Model Laid-Open No. 62-41923). I have. Further, a method for reducing the oil clearance of all bearings is also known.

[0004]

However, the diameter of the crank journal at the end is made larger than the diameter of the other crank journals, or the thickness of the crank arm at the end is made larger than the thickness of the other crank arms. Increasing the size has the problem of increasing the weight. Also, reducing the oil clearance of all bearings has the problem of increasing friction loss.

The present invention has been made in view of the above-mentioned problems, and has been made in consideration of the above-mentioned problems, and has an advantage in that lubrication that can reduce vibration of a connecting rod bearing at an end portion and improve vibration and noise without increasing weight or friction loss. It is intended to provide structure.

[0006]

According to the first aspect of the present invention, there is provided a lubrication system for an internal combustion engine having a lubricating oil supply path for supplying lubricating oil to a plurality of journal bearings and a plurality of connecting rod bearings. In the structure, there is provided a continuous lubricating means capable of continuously lubricating an end-side connecting rod bearing closest to at least one of both ends of the crankshaft, and can intermittently lubricate connecting rod bearings other than the same-side connecting rod bearing. Intermittent refueling means was provided.

In the invention described in claim 2, the continuous lubricating means includes an oil hole for supplying lubricating oil from the crank journal to the crankpin, and at least one of a journal bearing, a connecting rod bearing, a crank journal or a crankpin. The diameter of the oil hole of the end-side crank journal closest to at least one of both ends of the crankshaft is made larger than the diameter of the oil hole of the crank journal other than the end-side crank journal. .

[0008] In the third aspect of the present invention, the continuous lubrication means is provided in an oil hole for supplying lubricating oil from the end side crank journal to the end side crank pin and the end side journal bearing. And the groove formed so as to always communicate with the oil hole, and the intermittent oil supply means supplies lubricating oil from a crank journal other than the end crank journal to a crank pin other than the end crank pin. The oil hole to be supplied is constituted by an oil hole provided with an opening facing an oil supply passage provided in a crank journal other than the end-side crank journal from time to time when the crankshaft rotates.

According to the first aspect of the present invention, the lubricating oil is continuously supplied from the end journal bearing to the end connecting rod bearing by the continuous lubrication means, and the lubricating oil is continuously supplied from the journal bearings other than the end by the intermittent lubrication means. The lubricating oil is intermittently supplied to connecting rod bearings other than the side. Therefore, more lubricating oil is supplied to the end-side connecting rod bearing than to the other connecting rod bearings, and the lubricity is improved.

[0010] According to the second aspect of the present invention, the first aspect is provided.
In addition to the effects of the invention described in (1), lubricating oil is supplied to each connecting rod bearing by an oil hole, and since the groove is formed, the lubricating oil is supplied from the journal bearing to the connecting rod bearing without resistance. Further, since the diameter of the oil hole of the continuous oil supply means is set larger than the oil hole of the intermittent oil supply means, the amount of lubricating oil supplied to the end-side connecting rod bearing increases.

According to the third aspect of the present invention, the first aspect is provided.
Or in addition to the operation of the invention described in 2, since the groove is provided in the end journal bearing, there is no need to provide a groove in the crank journal or crank pin,
It does not reduce the rigidity of the crank journal or crankpin.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. As shown in FIG. 1, the crankshaft 11 includes a plurality of crank journals 21 provided at predetermined intervals on the same axis L1.
A crank arm 22 fixed to the longitudinal end of each journal 21, and a crank pin 2 fixed between the arms 22 and parallel to the journal 21.
And 3. The above crank journal 21
Is composed of end-side crank journals 21a provided at both ends of the crankshaft 11 and crank journals 21b other than the end-side crank journals.

The journal bearing 24 is provided on the outer periphery of the crank journal 21 and supports the end crank journal 21a.
And a journal bearing 24b other than the end that supports the crank journal 21b other than the end. In the crankshaft 11, a crank journal 21 is rotatably supported by journal bearings 24a and 24b. The journal bearings 24a and 24b are formed by joining an upper bearing portion 24U and a lower bearing portion 24L as shown in FIGS. The oil supply passage 25 is
It is formed on the upper bearing portion 24U.

The connecting rod bearing 26 is provided on the outer periphery of the crank pin 23. The connecting rod bearing 26 includes an end connecting rod bearing 26a adjacent to the end crank journal 21a and a connecting rod bearing 26b other than the end. The connecting rod bearings 26a, 26
b is formed by joining the upper bearing 26U and the lower bearing 26L as shown in FIGS. A connecting rod bearing 26a,
A connecting rod (not shown) is rotatably connected via 26b. The crankshaft 11 is moved by a reciprocating piston (not shown).
Is rotated by the connecting rod to rotate about the axis L1 of the crank journal 21.

FIG. 2 is a schematic sectional view taken in the direction of the arrow 2-2 in FIG. 1, and shows the positional relationship between the end side crank journal 21a and the crank pin 23. As shown in the figure, the end side crank journal 21a and the crank pin 2
3, the axes L1 and L2 are parallel to each other, and are connected to each other by a crank arm 22 as shown in FIG. An oil hole 27 that penetrates in a substantially diametrical direction is provided inside the end side crank journal 21a. The oil hole 28 penetrates through the crank arm 22 between the crank journal 21 a and the crank pin 23, and has one end connected to the vicinity of one end opening of the oil hole 27 and the other end opened to the outer peripheral surface of the crank pin 23. . A groove 29 is formed on the inner peripheral surface of the upper bearing portion 24U of the end-side journal bearing 24a so as to have a semi-circular cross section. The groove 29 communicates with the oil supply passage 25 and the oil supply passage 2.
5 has the same width as the diameter. Groove 29
Is disposed so as to face the opening of at least one end of the oil hole 27.

In this embodiment, the oil supply passage 25, the oil hole 2
7, the oil hole 28 and the groove 29 constitute a continuous oil supply means. The lubricating oil is distributed from an oil pump (not shown) to each oil supply passage 25 through an oil filter and a main oil gallery, and is supplied to each journal bearing 24. Here, since the groove 29 is formed in the upper bearing portion 24U of the end-side journal bearing 24a, the lubricating oil is supplied into the groove 29, and the journal bearing 24a and the crank journal 21 are formed.
It is led to the gap a.

Further, since the groove 29 is formed in a semicircular shape, a state where the groove 29 and the oil hole 27 are always in communication when the crank journal 21a rotates is formed. In addition, even when the oil hole 27 is located horizontally,
Since the oil hole 27 itself has a width, continuous communication between the groove 29 and the oil hole 27 is possible without interruption. The lubricating oil guided to the oil hole 27 passes through an oil hole 28 communicating with one end of the oil hole 27 and is guided to a gap between the crankpin 23 and the end-side connecting rod bearing 26a.

FIG. 3 is a schematic cross-sectional view as viewed from the direction of arrow 3-3 in FIG. 1, and shows the positional relationship between the crank journal 21b and the crank pin 23 except for the end side. As shown in the figure, the oil hole 30 penetrates the crank arm 22 between the crank journal 21b and the crank pin 23, one end is opened on the outer circumferential surface of the crank journal 21b, and the other end is formed on the outer circumferential surface of the crank pin 23. It is open. The opening of the oil hole 30 is provided at a position that can face the oil supply passage 25. The diameter of the oil hole 30 is set smaller than the diameter of the oil hole 27. Further, an oil hole that penetrates in a substantially diametric direction as shown in FIG. 2 is not provided inside the crank journal 21b other than the end side. Further, the groove as shown in FIG. 2 is not formed in the upper bearing portion 24U of the journal bearing 24b.

In the present embodiment, the oil supply passage 25 and the oil hole 30 constitute an intermittent oil supply means. That is, the lubricating oil distributed to the oil supply passage 25 is supplied into the journal bearing 24b other than the end side, and is guided to the gap between the journal bearing 24b and the crank journal 21b other than the end side. When the crank journal 21b rotates, there is a period in which the opening of the oil supply passage 25 and the opening of the oil hole 30 face each other. Since the communication state is formed only during this opposing period, the lubricating oil passes through the oil hole 30 and the crankpin 23
And the gap between the connecting rod bearings 26b other than the end side is intermittently supplied.

According to the present embodiment, since more lubricating oil is supplied to the end connecting rod bearing 26a than to the other connecting rod bearings 26b, wear of the end connecting rod bearing 26a is prevented, and vibration and noise are reduced. Generation can be suppressed. Further, since the groove 29 is formed, the lubricating oil can be supplied from the end journal bearing 24a to the end connecting rod bearing 26a without resistance. Since the oil hole 27 has a diameter larger than that of the oil hole 30, the amount of lubricating oil supplied to the end-side connecting rod bearing 26a can be increased.

Further, the continuous oil supply means includes an oil supply passage 25,
Since the oil hole 27, the oil hole 28 and the groove 29 constitute the intermittent oil supply means with the oil supply passage 25 and the oil hole 30, it is necessary to separately provide a plurality of oil pumps in order to change the lubricating oil supply amount. Absent. Further, since the groove 29 is provided in the upper bearing portion 24U of the end journal bearing 24a, it is not necessary to provide a groove in the crank journal or the crank pin, and the rigidity of the crank journal or the crank pin is not reduced.

The present invention can be configured as follows in addition to the above-described embodiment. (1) The journal bearing 24b other than the end side may be configured as shown in FIG. That is, the groove 31 may be formed on the inner peripheral surface of the upper bearing portion 24U of the journal bearing 24b as shown by a solid line in FIG. The same groove 31
Is the end journal bearing 24 in the above embodiment.
The length in the circumferential direction of the bearing is shorter than that of the groove 29 provided in a. With such a configuration, the intermittent oil supply means can be provided, and more lubricating oil can be supplied to the connecting rod bearing 26b other than the end side than in the case of the above embodiment.

The location where the groove is formed is not limited to the above, and the groove may be provided on any of the journal bearing, the connecting rod bearing, the crank journal or the crank pin, or a plurality of grooves may be provided. Furthermore, the circumferential length of the groove in the bearing is not limited to the above.
A groove may be provided on the entire inner peripheral surface of a. In this case, the oil hole 27 in FIG. 2 may be omitted, and even in such a case, continuous lubrication is possible.

Further, in FIG. 4, the circumferential end of the groove 31 is cut at right angles to the inner peripheral surface of the upper bearing portion 24U, but in FIG. A cut may be formed obliquely through a taper so as to gradually become deeper.

(2) The oil hole inside the end side crank journal 21a may be configured as shown in FIG. That is, in the embodiment, the end-side crank journal 21a
Although the oil hole 27 inside is provided so as to penetrate substantially in the diameter direction as shown in FIG. 2, the oil hole 32 may be provided at an eccentric position as shown in FIG. In this case, the groove 33 is longer than the groove 29 in the bearing circumferential direction so that the oil hole 32 and the groove can maintain communication even when the oil hole 32 is positioned horizontally. Therefore, the continuous oil supply means can be formed by the oil holes 32 and the grooves 33 as well.

(3) In the above embodiment, the diameter of the oil hole 28 is constant over the entire length.
4 shape. That is, the oil hole 34 may be formed such that the opening end on the side that opens to the crankpin 23 is flared. In this case, since the opening cross-sectional area of the oil hole 34 on the side of the crank pin 23 is large, the amount of lubricating oil supplied to the end-side connecting rod bearing 26a is increased, and lubricity can be improved. The shape of the opening end is not limited to the above, and for example, a groove formed in an arc-shaped cross section may be provided on the outer peripheral surface of the crankpin 23. In addition, the end portions of the oil holes 27 and 30 other than those described above may be shaped as shown in FIG.

(4) In the above embodiment, the oil hole 28 supplies the lubricating oil to the end-side connecting rod bearing 26a. In addition, the crank journal 21b and the end other than the end side adjacent to the end-side connecting rod bearing 26a are connected. Penetrates the crank arm 22 between the crank pins 23 supported by the side connecting rod bearing 26a, and has one end connected to the crank journal 21b.
Of the crank pin 23
An oil hole may be provided separately on the outer peripheral surface. In this case, more lubricating oil can be supplied to the end-side connecting rod bearing 26a than in the above-described embodiment.

(5) The continuous lubrication means and the intermittent lubrication means are:
It may be realized by adjusting the amount of lubricating oil discharged from the oil pump. That is, the end side crank journal 21a is provided with a first pump for continuously supplying lubricating oil, and the crank journals other than the end side are not provided with the first pump.
1b may be provided with a second pump for intermittently supplying lubricating oil. In the first embodiment, the oil hole 28 is used.
The oil hole 30 and the oil hole 30 have different diameters. However, when the pump is provided, oil holes having the same diameter can be used. When grooves are provided on the entire inner peripheral surface of the end-side connecting rod bearing 26a, the oil hole 27 in the first embodiment can be omitted.

Next, technical ideas other than the claims which can be understood from the above embodiments will be described together with their effects. (A) In the lubricating structure for an internal combustion engine according to any one of claims 1 to 3, an opening cross-sectional area of an oil hole opening in an end crank journal and a crank pin adjacent to the crank journal is different from that of the end side. A lubricating structure for an internal combustion engine, wherein an opening cross-sectional area of an oil hole opening in a crank journal and a crank pin adjacent to the crank journal is larger than that of the crank journal. In this case, more lubricating oil can be supplied to the end-side connecting rod bearing, the wear of the coaxial bearing can be prevented, and the generation of vibration and noise can be suppressed. Also,
According to the above configuration, even when the diameter of the oil hole over the entire length excluding the opening is the same, more lubricating oil can be supplied to the end-side connecting rod bearing.

(B) In the lubricating structure for an internal combustion engine according to any one of claims 1 to 3, the continuous lubricating means and the intermittent lubricating means include an oil hole for supplying lubricating oil from the crank journal to the crankpin, and a journal bearing. And a groove provided on at least one of the connecting rod bearing, the crank journal and the crank pin, and the groove of the end crank journal as the continuous lubrication means is the end crank journal as the intermittent lubrication means. A lubricating structure for an internal combustion engine, characterized in that the length of the bearing in the circumferential direction is longer than the grooves of the other crank journals. In this case, grooves are provided on the end side and other crank journals, but more lubricating oil is guided by the end side crank journal, so that more lubricating oil can be supplied to the end side connecting rod bearing and wear of the coaxial bearing is prevented. In addition, generation of vibration and noise can be suppressed.

[0031]

According to the first aspect of the present invention, since more lubricating oil is supplied to the end-side connecting rod bearing than to the other connecting rod bearings, wear of the end-side connecting rod bearing is prevented, and vibration is prevented. In addition, generation of noise can be suppressed.

According to the second aspect of the present invention, in addition to the effects of the first aspect of the present invention, since the groove is formed, the lubricating oil can be supplied from the journal bearing to the connecting rod bearing without resistance. it can. Further, since the oil hole of the continuous oil supply means has a diameter larger than that of the intermittent oil supply means, the amount of lubricating oil supplied to the end-side connecting rod bearing can be increased. Further, since the continuous oil supply means and the intermittent oil supply means are constituted by oil holes and grooves, it is not necessary to separately provide a plurality of oil pumps for changing the supply amount of the lubricating oil.

According to the third aspect of the present invention, in addition to the effects of the first or second aspect, the groove is provided on the end journal bearing, so that the groove is formed on the crank journal or the crank pin. Is not required, and the rigidity of the crank journal or the crank pin is not reduced.

Further, since the minimum amount of lubrication required for each pin portion is required, the size of the oil pump can be reduced, which greatly contributes to reducing engine friction (mechanical loss).

[Brief description of the drawings]

FIG. 1 is a side view showing an internal combustion device of the present embodiment.

FIG. 2 is a schematic cross-sectional view of the internal combustion apparatus of FIG. 1 viewed from the direction of arrow 2-2.

FIG. 3 is a schematic cross-sectional view of the internal combustion device of FIG.

FIG. 4 is a schematic sectional view of an internal combustion apparatus according to another embodiment.

FIG. 5 is a schematic sectional view of an internal combustion apparatus according to another embodiment.

FIG. 6 is a schematic sectional view of an internal combustion apparatus according to another embodiment.

[Explanation of symbols]

11 ... Crankshaft, 21 ... Crank Shanar,
Reference numeral 22: crank arm, 23: crank pin, 24: journal bearing, 25: oil supply passage, 26: connecting rod bearing, 27, 28: oil hole, 29: groove.

Claims (3)

[Claims] In a lubricating structure for an internal combustion engine having a lubricating oil supply path for supplying lubricating oil to a plurality of journal bearings and a plurality of connecting rod bearings, an end-side connecting rod bearing closest to at least one of both ends of a crankshaft is provided. A lubricating structure for an internal combustion engine provided with a continuous lubricating means capable of continuously lubricating the same, and intermittent lubricating means capable of intermittently lubricating connecting rod bearings other than the connecting rod bearing at the same end. 2. The continuous oil supply means includes an oil hole for supplying lubricating oil from a crank journal to a crankpin, and a groove provided on at least one of a journal bearing, a connecting rod bearing, a crank journal or a crankpin. 2. The oil pump according to claim 1, wherein the diameter of the oil hole of the end-side crank journal closest to at least one of both ends of the crankshaft is larger than the diameter of the oil hole of the crank journal other than the end-side crank journal. Lubrication structure of internal combustion engine. 3. The continuous lubrication means is provided in an oil hole for supplying lubricating oil from the same end crank journal and the same end crank journal to an end crank pin and the end journal bearing. The intermittent oil supply means is an oil hole for supplying lubricating oil from a crank journal other than the end crankpin to a crankpin other than the end crankpin. The internal combustion engine according to claim 1, wherein the internal combustion engine includes an oil hole having an opening opposed to an oil supply passage provided in a crank journal other than the end-side crank journal from time to time when the crankshaft rotates. Lubrication structure.