JPH085291Y2 - Lubricating oil supply mechanism for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention mainly relates to a lubricating oil supply mechanism for an internal combustion engine that supplies lubricating oil to a crankpin.

[Prior Art] Generally, a lubricating oil supply mechanism of this type includes a gear case having a lubricating oil pump, a crank shaft having one end facing the gear case, and a lubricating oil from the lubricating oil pump formed in the crank shaft. And an oil passage in the crankshaft for supplying the pin (for example, Japanese Patent Laid-Open No. 59-28007: Feb. 1984).
Issued 14th of May). The gear case is provided with an oil passage in the gear case for supplying hydraulic oil from the lubricating oil pump. Then, in order to connect the oil passage in the gear case and the oil passage in the crankshaft, one end of the crankshaft is fitted and inserted in the gear case while maintaining liquid tightness.

According to the above structure, the lubricating oil supplied from the lubricating oil pump is supplied to the crank pin via the oil passage in the crank shaft, and the working portion of the crank pin is lubricated.

[Problems to be solved by the invention] However, in that structure, in order to make the oil passage in the gear case and the oil passage in the crankshaft communicate with each other, one end of the crankshaft is fitted and inserted in the gear case while maintaining liquid tightness. Therefore, the vibration of the crankshaft is transmitted to the gear case, which may cause abnormal noise in the gear case. In addition, the crankshaft may not operate smoothly due to vibration resistance of the crankshaft and the gear case.

 The present invention aims to solve the above problems.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a gear case having a lubricating oil pump, a crankshaft having one end facing the gearcase, and the lubricating oil pump formed in the crankshaft. In a lubricating oil supply mechanism for an internal combustion engine, comprising: an internal crankshaft oil passage for supplying lubricating oil from a crankpin to the crankpin; an internal oil passage in the gear case communicating with the discharge opening of the lubricating oil pump; A crankshaft is provided by providing a hydraulic chamber that communicates an oil passage with the oil passage in the crankshaft, and inserting a cylindrical seal ring with a small outer diameter at one end into the hydraulic chamber from the other end while maintaining liquid tightness. Slidably in the axial direction of the crankshaft, the one end of the crankshaft is formed with a recess corresponding to the outer diameter of the seal ring having a small diameter, and one end of the seal ring and one end of the crankshaft are halved. A gap is formed in the radial direction, and one end of the seal ring and one end of the crankshaft are in close contact with each other in the axial direction. The seal ring maintains liquid tightness and the oil passage in the gear case It is characterized by communicating with the oil passage in the crankshaft.

[Operation] The vibration of the crankshaft is absorbed by the seal ring slidably moving in the crankshaft direction in the hydraulic chamber.

[Embodiment] In the embodiments described below, the same members are designated by the same reference numerals, and the description thereof will be omitted.

(First Embodiment) FIG. 1 is a schematic partial sectional view of an internal combustion engine adopting the present invention.
In the figure, 10 is a gear case, which is provided with a lubricating oil pump 11 on its side part. The lubricating oil pump 11 is provided with a driven pump shaft 12, and the pump shaft 12 is concentrically connected to a cam shaft 13. When the cam shaft 13 rotates the pump shaft 12, the pump 11 discharges the hydraulic oil supplied from an oil pan (not shown) from the discharge port 14.

The pump discharge port 14 communicates with an upper end portion of a gear case internal oil passage 15 formed in the gear case 10. The oil passage 15 in the gear case extends vertically in FIG. 1, and its lower end communicates with the hydraulic chamber 16 having a circular cross section.

A crankshaft 17 faces the hydraulic chamber 16. The hydraulic chamber 16 is opened concentrically with the crankshaft 17. A cylindrical seal ring 18 is fitted in the hydraulic chamber 16 so as to be slidable in the axial direction of the crankshaft 17, and its tip end is joined to the crankshaft end. The seal ring 18 is a metallic member, and has a bore 19 in the center thereof. Also crank shaft 17
Is an oil passage in the crankshaft communicating with the bore 19 of the seal ring 18.
Equipped with 20. The crankshaft oil passage 20 includes a crank arm 21, a connecting rod 22, and a crankpin metal 23.
The lubricating oil is supplied to the crank pin 27 through the oil passages 24, 25 and 26 respectively provided in the crank pin 27. In this embodiment, the anti-crankshaft of the seal ring 18
A compression coil spring 28 for adjusting pressure is contracted on the 17 side, and the spring force presses the seal ring 18 against the end surface of the crankshaft 17.

As shown in the lower side of FIG. 1 and in FIG.
Has a small diameter tip 29 concentrically,
The end surface of 17 is provided with an annular small-diameter recess 30 with which the small-diameter tip 29 is in pressure contact. As shown in the drawing, a radial gap L is formed between the small diameter tip portion 29 and the small diameter recess 30. As a result, the seal ring 18 and the end of the crankshaft 17 are connected while maintaining liquid tightness, and vibration from the crankshaft 17 side can be damped as much as possible.

According to the above structure, as shown in FIG. 1, the rotation of the cam shaft 13 drives the pump shaft 12 and, as a result,
The lubricating oil pump 11 discharges lubricating oil from an oil pan (not shown).
Discharge from 14. Then, the lubricating oil discharged from the discharge port 14 is supplied into the hydraulic chamber 16 via the gear case internal oil passage 15, and the hydraulic pressure pushes the seal ring 18 toward the crankshaft 17 side, and the bore in the seal ring 18 is also pressed. 19. Lubricating oil is supplied to the crankpin 27 via the oil passage 20 in the crankshaft and the oil passages 24, 25, 26. The compression coil spring 28 works in conjunction with the hydraulic pressure in the hydraulic chamber 16 to move the seal ring 18 to the crankshaft 17
It is pushing to the side. Therefore, the small diameter tip of the seal ring 18
29 and the small-diameter recess 30 of the crankshaft 17 are joined with an appropriate pressure, and as a result, sufficient liquid tightness is maintained.

Moreover, since the seal ring 18 is slidably fitted in the hydraulic chamber 16 in the axial direction of the crankshaft 17, the crankshaft 17
Even if the side vibration propagates to the seal ring 18, it is damped by the pressure of the hydraulic chamber 16 and the spring force of the compression coil spring 28 described above. Therefore, the vibration of the crankshaft 17 is not transmitted to the gear case 10, and there is no possibility that the gear case 10 vibrates and produces an abnormal noise. Further, since vibration resistance does not occur between the crankshaft 17 and the gear case 10, the crank operation can be performed smoothly.

(Second Embodiment) In the embodiment shown in FIG. 3, a pipe 34 that fits into the bore 19 of the seal ring 18 and the oil passage 20 in the crankshaft is adopted. Further, as shown in the lower side of FIG. 3, an O-ring arranged on the outer periphery of the pipe 34 by providing an annular groove 35 on the crankshaft end face.
36 is fitted. By adopting the pipe 34 and the O-ring 36, the liquid tightness of the joint portion between the seal ring 18 and the crankshaft 17 can be maintained more completely.

In the embodiment shown in FIG. 3, the compression coil spring 28 described in FIGS. 1 and 2 is omitted. Further, when the second embodiment shown in FIG. 3 is adopted, the O-ring 36 may be omitted.

(Third Embodiment) In the embodiment shown in FIG.
The structure in which the driven part 41 and the driven part 41 are divided is disclosed. Further, in the embodiment shown in FIG. 4, the bottom of the hydraulic chamber 16 is provided with the gear case 10.
And a lid 42 that is a separate body.

The lid 42 is provided with a boss portion 44 integrally extending from the flange portion 43 to the crankshaft 17 side, and the boss portion 44 is a gear case.
It is fitted in the large-diameter recessed portion 45 provided in 10. Large diameter recess 45
Communicate with the hydraulic chamber 16 concentrically from the side opposite to the crankshaft 17. The lid boss portion 44 is provided with a recess 46 that is recessed toward the side opposite to the crankshaft 17, and a through hole 46a communicating with the oil passage 15 in the gear case is formed in the peripheral wall of the recess 46. The drive section 40 and the driven section 41 are concentrically arranged between the end surface of the boss portion 44 and the end surface of the crankshaft 17.

The drive unit 40 includes a slide contact portion 47 that slides in contact with the inner peripheral surface of the hydraulic chamber 16,
The sliding contact portion 47 is integrally provided with a small-diameter cylindrical portion 48 concentrically extending toward the crankshaft 17, and the inner peripheral surface of the driven portion 41 is slidably fitted to the outer peripheral surface of the small-diameter cylindrical portion 48. There is. A small-diameter tip portion 29 is integrally formed with the driven portion 41 on the crankshaft 17 side, and is joined to the small-diameter recess 30 of the crankshaft 17.

A compression coil spring 28 is compressed between the end surface of the sliding contact portion 47 and the end surface of the driven portion 41. It should be noted that concentric holes are bored in the driving portion 40 and the driven portion 41, respectively, and these holes constitute the bore 19 of the seal ring 18.

According to the above structure, when the crankshaft 17 is attached, the rear end face of the drive portion 40 is in pressure contact with the front end face of the boss portion 44 as shown from the center line C in FIG. Extend in the axial direction of the crankshaft 17. The driven force 41 is pressed toward the crankshaft 17 by the spring force, and the small-diameter tip portion 29 is joined to the small-diameter recess 30.

When lubricating oil is supplied from the oil passage 15 in the gear case through the through hole 46a, the hydraulic pressure in the recess 46 rises while being regulated against the compression coil spring 28. The drive unit 40 is a recess
Since the hydraulic pressure in the cylinder 46 and the reaction force of the compression coil spring 28 balance each other, the stationary state causes the hydraulic pressure in the recess 46 to rise, so that the crankshaft 17 as shown from the center line C in FIG. 4 to the lower side.
It is pressed to the side. In the embodiment shown in FIG. 4, the drive unit 40
Is provided with a drain port 49 that communicates with the hydraulic chamber 16 when the compression coil spring 28 is compressed and moved by a certain amount.
After the hydraulic pressure of 46 reaches a certain level, the lubricating oil drain port 49
It is drained from and it doesn't press up any more.

Fourth Embodiment In the embodiment shown in FIG. 5, the lubricating oil pump 11 is a pump shaft.
The structure when driven by the crankshaft 17 via 12 is shown.

The seal ring 18 is formed in a cylindrical shape, the outer peripheral surface of which is slidably fitted to the inner peripheral surface of the hydraulic chamber 16 provided in the gear case 10, and the front end surface thereof is joined to the crankshaft 17. are doing.

A cylindrical bush 50 is fitted inside the crank shaft 17, and the tip end portion of the pump shaft 12 is fitted inside the bush 50.

As shown in FIG. 6, the cross section of the tip portion of the pump shaft 12 is
It is cut flat and the inner circumference of the bush 50 is also the pump shaft.
The flat shape along the cross section of the tip of 12 has gaps γ and δ, respectively.
It is formed by extending. The construction, operation, etc. of the pump shaft 12, the bush 50, etc. are disclosed in detail in Japanese Utility Model Laid-Open No. 59-154809.

Also in the above configuration, the lubricating oil discharged from the lubricating oil pump 11 is supplied from the discharge port 14 to the hydraulic chamber 16 via the oil passage 15 in the gear case, and the bore 19 while urging the seal ring 18 toward the crankshaft 17 side. , And the oil passage 20 in the crankshaft, to the crankpin 27 (FIG. 1).

[Effects of the Invention] As described above, according to the present invention, a gear case having a lubricating oil pump, a crank shaft having one end facing the gear case, and a lubricating oil from the lubricating oil pump formed in the crank shaft are provided. A lubricating oil supply mechanism for an internal combustion engine, comprising: a crankshaft internal oil passage for supplying to a crankpin; a gear case internal oil passage communicating with a discharge port of the lubricating oil pump; a gear case internal oil passage; An oil pressure chamber communicating with the in-shaft oil passage is provided, and a cylindrical seal ring whose outer diameter at one end has a small diameter is inserted into the oil pressure chamber from the other end while maintaining liquid tightness and sliding in the axial direction of the crankshaft. It is movably provided, and one end portion of the crankshaft forms a recess corresponding to the outer diameter of the seal ring having a small diameter, and one end of the seal ring and one end portion of the crankshaft form a radial gap. In addition, one end of the seal ring and one end of the crankshaft are in close contact with each other in the axial direction, and the oil ring inside the gear case and the oil passage inside the crankshaft are kept in a liquid-tight state by the seal ring. Therefore, the vibration of the crankshaft is not transmitted to the gear case via the seal ring, and no abnormal noise is generated in the gear case. Moreover, since the vibration of the crankshaft is not transmitted to the gear case, the crank operation can be performed smoothly.

Since the differential pressure of the hydraulic oil is used to maintain the liquid tightness between the seal ring and the crankshaft, it is not necessary to use a spring having a strong elastic force. Moreover, since the liquid pressure is maintained by using the differential pressure of the hydraulic oil, even if the spring used as an auxiliary to hold the seal ring before the hydraulic oil is supplied is damaged during the hydraulic oil supply. No oil leakage will occur.

Moreover, according to the present invention, a cylindrical seal ring is provided in the hydraulic chamber so as to be slidable in the crankshaft direction. Therefore, it can be easily implemented without requiring a large design change.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic partial sectional view of an internal combustion engine adopting the present invention, FIG. 2 is an enlarged view of an essential part of FIG. 1, and FIG. 3 is an enlarged view of an essential part of another embodiment. FIG. 4 is an enlarged schematic view of an essential part showing still another embodiment, FIG. 5 is an enlarged schematic view of an essential part showing yet another embodiment, and FIG. 10 ... Gear case, 11 ... Lubricating oil pump, 15 ... Oil passage in gear case, 16 ... Hydraulic chamber, 17 ... Crank shaft, 18 ... Seal ring, 20 ... Oil passage in crank shaft

Claims (1)

[Scope of utility model registration request] 1. A gear case having a lubricating oil pump, a crank shaft having one end facing the gear case, and a crank shaft oil passage formed in the crank shaft for supplying lubricating oil from the lubricating oil pump to a crank pin. In a lubricating oil supply mechanism for an internal combustion engine including: a gear case inner oil passage communicating with the discharge port of the lubricating oil pump; and a hydraulic chamber communicating the gear case inner oil passage with the crankshaft inner oil passage in the gear case. And a cylindrical seal ring whose one end has a small outer diameter is inserted into the hydraulic chamber from the other end while maintaining liquid tightness so as to be slidable in the axial direction of the crankshaft. One end portion forms a recess corresponding to the outer diameter of the seal ring having a small diameter, one end portion of the seal ring and one end portion of the crankshaft form a radial gap, and
One end of the seal ring and one end of the crank shaft are in close contact with each other in the axial direction, and the oil passage in the gear case and the oil passage in the crank shaft are communicated with each other while maintaining liquid tightness by the seal ring. A lubricating oil supply mechanism for an internal combustion engine.