JP2011236818A - Lubrication device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lubrication device for an internal combustion engine which when a journal bearing in the lubrication device is constituted by a rolling bearing, prevents the influence of oil leakage from the rolling bearing on a connecting rod large-end bearing and reduces a load of an oil pump.SOLUTION: The lubrication device for an internal combustion engine includes an oil supply route to a journal bearing 23 of a crank shaft 21 and the connecting rod large-end bearing 26, wherein the journal bearing 23 is constituted by the rolling bearing, the crank shaft is provided with a main oil supply route 34, and an oil supply route to the journal bearing 23 and the connecting rod large-end bearing 26 comprises an oil supply route 38 for the journal bearing and an oil supply route 39 for the connecting rod large-end bearing, each branched from the main oil supply route 34 and independent from each other.

Description

  The present invention relates to a lubricating device for an internal combustion engine such as an automobile, and more particularly to a reduction in the load of an oil pump.

  FIG. 2 shows an oil supply system in a conventional lubricating device for an internal combustion engine (Patent Document 1). The bearings to be lubricated in this lubrication system are fitted around a journal bearing 3 supporting the journal 2 of the crankshaft 1, a connecting rod large end bearing 5 fitted around the crankpin 4, and a piston pin 6. This is the connecting rod small end bearing 7. The journal bearing 3 and the connecting rod large end bearing 5 are sliding bearings made of a metal divided into two parts. The connecting rod small end bearing 7 constitutes a sliding bearing by directly fitting the connecting rod small end portion 8 to the piston pin 6 without interposing a bearing member.

  A journal bearing oil supply path 11 branched for each journal bearing 3 of the crankshaft 1 is provided in a main gallery 10 connected to an oil pump 9 of the internal combustion engine. Each journal bearing oil supply path 11 passes through the journal 2 from the bearing support 12 provided in the engine block through the oil hole 13 of the journal bearing 3 in the radial direction and reaches the inner peripheral surface on the opposite side of the journal bearing 3. Thus, the journal bearing 3 is lubricated.

  The journal bearing oil supply path 11 is branched obliquely inside the journal 2, and the connecting rod large end bearing oil supply path 14 is formed by the branched path. The oil supply path 14 reaches the inner diameter surface of the connecting rod large end bearing 5 and supplies oil thereto. The connecting rod large end bearing 5 has an oil hole 15. The connecting rod large end portion 16 is provided with an oil injection hole 17 that reaches the outer peripheral surface of the connecting rod large end portion 16 from the bearing 5. The connecting rod small end bearing 7 and the sliding surface 20 of the piston 19 are lubricated by the lubricating oil injected from two locations of the oil injection hole 17 and the oil injection nozzle 18 communicating with the main gallery 10. Yes.

  As described above, the lubrication system of the journal bearing 3 and the connecting rod large end bearing 5 in the conventional lubrication apparatus belongs to the same system from the journal bearing lubrication path 11 to the oil injection hole 17, and the journal bearing is viewed from the lubrication flow direction. 3 is on the upstream side, and the connecting rod large end bearing 5 is on the downstream side.

  On the other hand, the needle bearing has a high load capacity and high rigidity for a small bearing projected area, and has excellent characteristics that it can be operated with a small amount of lubricating oil as well as low friction compared to a sliding bearing. . Focusing on this point, a proposal to use a needle bearing as the journal bearing 3 of the crankshaft 1 has been made early (Patent Document 2).

  Based on such a proposal, in particular, in order to reduce the friction of the bearing and reduce the amount of lubricating oil, it is conceivable to use not only the needle bearing but also a general rolling bearing as the journal bearing 3.

  However, since a rolling bearing generally has a large space volume, it has a characteristic that a so-called hydraulic pressure drop is likely to occur due to leakage of lubricating oil. For this reason, when the upstream journal bearing is constituted by a rolling bearing, the amount of oil supplied to the downstream connecting rod large end bearing is reduced, which may cause a problem of poor lubrication in the connecting rod large end bearing. .

  Further, in the lubricating device for an internal combustion engine using a slide bearing as a journal bearing as in the conventional example (see FIG. 2), the lubrication system for the journal bearing and the lubrication system for the connecting rod large end bearing are separated. It has been conventionally known (see Patent Documents 3 and 4).

  The oil supply path to the journal bearing in this case is configured to supply oil from the outer peripheral surface of the journal bearing via an oil supply path provided in the bearing support portion of the engine block from the oil pump. In addition, the oil supply path from the oil pump through the oil supply path provided in the crankshaft and the oil supply hole provided in the crankshaft to the connecting rod large end bearing from the inner peripheral surface of the connecting rod big end bearing. The so-called crankshaft center refueling system is used.

  Thus, by making the oil supply path to the journal bearing and the connecting rod large end bearing different systems, it is possible to prevent the influence of oil leakage occurring in the journal bearing from reaching the connecting rod large end bearing.

  However, in the above-described lubrication apparatus in which the oil supply path of the journal bearing and the connecting rod large end bearing is separated, the oil supply path to the journal bearing becomes long, and the direction of oil supply to the journal bearing depends on the rotation of the crankshaft. Since the direction is against the centrifugal force, there is a problem that the load of the oil pump increases.

JP 7-27126 A U.S. Pat. No. 1,192,488 and drawings JP 2007-224859 A JP-A-6-66119

  Therefore, in the present invention, when the journal bearing in the lubricating device of the internal combustion engine is configured by a rolling bearing to reduce friction and reduce lubricating oil, the influence of oil leakage in the rolling bearing is affected by the connecting rod large end bearing. The object is to reduce the load of the oil pump.

  In order to solve the above-described problems, the present invention provides a lubricating device for an internal combustion engine having a journal bearing of a crankshaft and an oil supply path for a connecting rod large end bearing, wherein the journal bearing is constituted by a rolling bearing, A main oil supply path is provided on the shaft, and an oil supply path for the journal bearing and the connecting rod large end bearing is constituted by a journal bearing oil supply path and a connecting rod large end bearing oil supply path which are branched from the main oil supply path and are independent of each other. It was assumed.

  The main oil supply passage is provided axially at the center of the journal portion and the crankpin portion of the crankshaft, and the journal portion and the crankpin portion have an angle with respect to the center. The structure connected by the inclination channel | path can be taken.

  The journal bearing oil supply path may be configured to branch radially from the main oil supply path in the journal portion of the crankshaft.

  As described above, in the present invention, the oil supply path for the journal bearing and the connecting rod large end bearing is divided by the journal bearing oil supplying path and the connecting rod large end bearing oil supplying path branched from the main oil supplying path provided in the crankshaft, respectively. Since it is configured, oil supply to the journal bearing and the connecting rod large end bearing is independent of each other. For this reason, even if lubricating oil leaks in the journal bearing, it is possible to ensure a stable oil supply amount to the connecting rod large end bearing.

  Further, since the journal bearing is constituted by a rolling bearing, the required amount of oil is less than in the case of using a conventional sliding bearing, and the oil supply path is shortened because both the oil supply paths are of the crankshaft center oil supply system. In addition, the load of the oil pump can be greatly reduced in combination with the addition of the lubricating oil pumping action due to the centrifugal force accompanying the rotation of the crankshaft.

FIG. 1 is an oil supply route diagram of the first embodiment. FIG. 2 is a prior art oiling path diagram.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

[Embodiment 1]
FIG. 1 shows a lubricating device for an internal combustion engine according to a first embodiment. The bearings to be lubricated in this case are, as in the conventional case, a journal bearing 23 that supports the journal 22 of the crankshaft 21 and a connecting rod large end that is fitted around the crankpin 24 and supports the connecting rod large end 25. The connecting rod small end bearing 29 is fitted around the partial bearing 26 and the piston pin 27 and supports the connecting rod small end portion 28. All of these bearings are constituted by rolling bearings (in the illustrated case, needle bearings).

  The oil supply system is configured as follows. That is, a journal main oil supply path 31 is provided at the center of the journal 22 of the crankshaft 21, and a crankpin main oil supply path 32 is provided at the crankpin 24. The main oil supply paths 31 and 32 of these parts are mutually connected by the inclination path 33, and the main oil supply path 34 is comprised as a whole. Among these, in the journal 22 at one end portion of the crankshaft 21, the journal portion main oil supply passage 31 is connected to the main gallery 36 and further to the oil pump 35 through a radial introduction passage 37.

  Each journal 22 is provided with a journal bearing oil supply path 38 that is branched from the journal main oil supply path 31 in the radial direction. The journal bearing oil supply passage 38 reaches the inner diameter surface of the journal bearing 23 and supplies oil to the bearing 23. Further, in the crank pin 24, a connecting rod large end bearing oil supply path 39 is provided on the extension of the inclined path 33 from the crank pin main oil supply path 32 with the same inclination angle. The connecting rod large end bearing oil supply passage 39 reaches the inner diameter surface of the connecting rod large end bearing 26 and supplies oil to the bearing 26.

  As described above, the oil supply system for the journal bearing 23 and the connecting rod large end bearing 26 is independently supplied from the journal bearing oil supply path 38 and the connecting rod large end bearing oil supply path 39 connected in parallel to the main oil supply path 34. The crankshaft center oiling system is used.

  An oil injection hole 40 that obliquely penetrates the connecting rod large end 25 is provided on the outer diameter surface of the connecting rod large end bearing 26. The sliding surface 43 of the connecting rod small end bearing 29 and the piston 42 is lubricated by the lubricating oil injected from the oil injection hole 40 and the oil injection nozzle 41 connected to the main gallery 36. ing.

  The internal combustion engine lubrication apparatus according to the first embodiment is configured as described above. When the internal combustion engine is driven, the lubricating oil is supplied from the oil pump 35 to the main oil supply path 34 of the crankshaft 21 through the main gallery 36 and the introduction path 37. Supplied. A journal bearing oil supply path 38 and a connecting rod large end bearing oil supply path 39 are connected to the main oil supply path 34, so that the journal bearing 23 and the connecting rod large end bearing 26 pass through these oil supply paths 38 and 39, respectively. Refueled.

  Further, the lubricating oil injected from the oil injection hole 40 via the connecting rod large end bearing 26 and the lubricating oil injected from the oil injection nozzle 41 via the main gallery 36 are connected to the connecting rod small end bearing 29 and the piston. The sliding surface 43 of 42 is lubricated.

  As described above, the oil supply paths 38 and 39 for the journal bearing 23 and the connecting rod large end bearing 26 constitute separate oil supply paths that are independent of each other. However, it is possible to avoid the influence on the connecting rod large end bearing 26.

  Further, as described above, the oil supply path is shortened by adopting the crankshaft center oil supply method as compared with the conventional method (see FIG. 2). Further, since both the journal bearing oil supply path 38 and the connecting rod large end bearing oil supply path 39 are formed in the radial direction from the main oil supply path 34, the lubricating oil supplied through the path is accompanied by the rotation of the crankshaft 21. Pump action by centrifugal force is added.

  Further, since the journal bearing 23, the connecting rod large end bearing 26 and the connecting rod small end bearing 29 are each constituted by a rolling bearing, the oil supply amount is reduced in comparison with a conventional case constituted by a sliding bearing. The pump 35 can be downsized and the load can be reduced, which contributes to a reduction in fuel consumption of the entire internal combustion engine.

DESCRIPTION OF SYMBOLS 1 Crankshaft 2 Journal 3 Journal bearing 4 Crankpin 5 Connecting rod big end bearing 6 Piston pin 7 Connecting rod small end bearing 8 Connecting rod small end 9 Oil pump 10 Main gallery 11 Journal bearing oil supply path 12 Bearing support 13 Oil hole 14 Connecting rod large end bearing oil supply path 15 Oil hole 16 Connecting rod large end 17 Oil injection hole 18 Oil injection nozzle 19 Piston 20 Sliding surface 21 Crankshaft 22 Journal 23 Journal bearing 24 Crank pin 25 Connecting rod large end 26 Connecting rod large end Bearing 27 Piston pin 28 Connecting rod small end portion 29 Connecting rod small end bearing 31 Journal portion main oiling path 32 Crankpin portion main oiling path 33 Inclined path 34 Main oiling path 35 Oil pump 36 Main gallery 37 Introduction path 38 Journal bearing oil supply path 39 Connecting rod large end bearing oil supply path 40 Oil injection hole 41 Oil injection nozzle 42 Piston 43 Sliding surface

Claims (6)

  In a lubricating device for an internal combustion engine having an oil supply path for a journal bearing of a crankshaft and a connecting rod large end bearing, the journal bearing is constituted by a rolling bearing, the main oiling path is provided on the crankshaft, and the journal bearing and the connecting rod 2. An internal combustion engine lubrication apparatus according to claim 1, wherein an oil supply path for the large end bearing is constituted by a journal bearing oil supply path and a connecting rod large end bearing oil supply path which are branched from the main oil supply path and are independent of each other.   The main oil supply path connects a journal part main oil supply path provided at the center of the journal part of the crankshaft, a crankpin part main oil supply path provided at the center of the crankpin part, and these oil supply paths. 2. The internal combustion engine lubricating device according to claim 1, wherein the lubricating device is constituted by an inclined path.   The journal bearing oil supply path is formed by branching from the journal main oil supply path in the radial direction, and the connecting rod large end bearing oil supply path is in the radial direction with an angle of the inclined path from the crankpin main oil supply path. The lubricating device for an internal combustion engine according to claim 2, wherein the lubricating device is formed by branching into two.   The connecting rod large end portion is provided with an oil injection hole communicating with the inside of the connecting rod large end portion bearing, and the connecting rod small end bearing is lubricated by the lubricating oil injected from the oil injection hole. The internal combustion engine lubricating device according to any one of claims 1 to 3.   The lubricating device for an internal combustion engine according to claim 4, wherein both the connecting rod large end bearing and the connecting rod small end bearing are constituted by rolling bearings. 6. A lubricating device for an internal combustion engine according to claim 1, wherein each of the rolling bearings constituting the journal bearing, the connecting rod large end bearing, and the connecting rod small end bearing is a needle bearing.

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