JPH0727137A - Journal bearing - Google Patents

Abstract

PURPOSE:To improve durability of the periphery of a through-hole, and improve an installing performance by providing the through-hole penetrating through a fixed surface and a sliding surface as an oil flow hole, and reducing sliding resistance by forming an oil film on the sliding surface. CONSTITUTION:A rigid member 4 and a lining 5 are brought into pressure contact with each other, and are formed as a main body of a journal bearing 1. A projecting part 9 having a hole 8 to constitute an oil flow passage 7 by being formed integrally with a through-hole 6 of the main body, is arranged on the fixed surface 2. As a result, when the projecting part 9 is fitted to an oil passage 12 of a connecting rod 10 or the like, reliable positioning becomes possible, and the opening area of the oil flow passage 7 to the oil passage 12 is secured easily and reliably. Since the periphery of the through-hole 6 is reinforced by the projecting part 9, deformation around the through-hole 6 caused by an oil pressure change in an oil film formed on a sliding surface 3 is restrained, and durability against separation of the lining 5 is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a journal bearing, and in particular, a through hole penetrating a fixed surface and a sliding surface is provided as an oil circulation hole, and an oil film is formed on the sliding surface to reduce sliding resistance. Regarding journal bearings.

[0002]

2. Description of the Related Art Conventionally, a journal bearing has been known as one of refueling type rotary bearings. As such a journal bearing, generally, a rigid member made of iron or the like is pressed with a lining made of aluminum or the like, sintered or cast to form a main body, and a through hole penetrating the main body is provided.

The journal bearing having such a structure functions as a rotary bearing by using the rigid member side as a fixed surface and the lining side as a sliding surface, and forming an oil film of lubricating oil on this sliding surface. It will be demonstrated
The through hole provided in the main body functions as an introduction hole or a discharge hole for the lubricating oil that forms an oil film.

As described above, since the journal bearing is intended to reduce the sliding resistance by forming an oil film on its sliding surface, it is essential that an appropriate oil film is formed at the time of use. There are roughly two points to consider when using a rotary system.

One is the assembling precision when assembling the journal bearing to a fixed system such as a housing. The through hole provided in the journal bearing is aligned with the oil passage provided in the fixed system to ensure a desired flow rate. It is required to realize a distribution channel. And the other is
This is to set the area of the through hole that opens on the sliding surface to the minimum necessary.To form an oil film as wide as possible even in the through hole part and to secure appropriate sliding resistance in the peripheral part as well. It is required.

In this case, with respect to the former requirement, that is, the requirement regarding the assembling accuracy of the journal bearing, Japanese Utility Model Laid-Open No. 61-57227 discloses a structure of a journal bearing which can easily meet the above requirement.

In this journal bearing, the housing, which is a fixed system, is aligned with the journal bearing by using a tubular fixing pin having an oil flow path formed along the central axis. By inserting into both the oil passage of the housing and the through hole of the journal bearing, it is inevitable that the both are aligned and the desired oil circulation path is secured.

[0008]

However, in the case where an oil flow path is formed in the fixed pin as in the conventional journal bearing described above, the through hole of the journal bearing opened so that the fixed pin can be inserted has a necessary oil. The diameter is significantly larger than the diameter of the distribution channel. In other words, such a configuration satisfies the requirement regarding the assembly accuracy of the above-mentioned two requirements required for the journal bearing, but is completely contrary to setting the opening area of the through hole small.

Further, in the conventional journal bearing described above, the differential pressure between the hydraulic pressure in the oil passage of the housing and the hydraulic pressure of the oil film portion of the journal bearing is directly applied to the fixing pin. Therefore, for example, when the oil pressure in the oil film portion periodically fluctuates as the rotary system rotates, stress is repeatedly applied to the fixed pin in the axial direction due to the fluctuation of the hydraulic pressure.

The repetitive stress is transmitted to the through-hole portion of the journal bearing in which the fixing pin is inserted and held, causing the lining to be prematurely separated from the rigid member of the journal bearing.

The present invention has been made in view of the above points, and a protrusion having a hole that forms an oil passage hole integrally with a through hole that opens in the sliding surface is provided on the fixed surface of the journal bearing. In this way, it aims at providing the journal bearing which can solve the said subject.

[0012]

The above object is a member that is interposed between a shaft and a housing to reduce sliding resistance when the two relatively rotate, and one surface of the main body. Is a fixed surface and the other surface is a sliding surface, and a through hole penetrating the main body is provided, and in a journal bearing for reducing sliding resistance by forming an oil film on the sliding surface, in the fixed surface, This is achieved by a journal bearing provided with a convex portion having a hole that forms an oil circulation hole integrally with the through hole.

[0013]

In the journal bearing according to the present invention, an oil film is formed on the sliding surface to reduce sliding resistance. On this occasion,
The through hole formed in the main body is set to a minimum diameter that can secure the flow rate of the lubricating oil necessary for forming an oil film, and an oil film having an appropriate area is formed even in the periphery of the through passage.

On the other hand, a convex portion is formed on the fixed surface to form an oil flow passage integrally with the through hole. Therefore, in the fixed system that holds the journal bearing,
If an oil passage that can be fitted to this convex portion is formed, the positioning of the journal bearing is inevitably performed by fitting the convex portion to this oil passage.

Further, the portion where the differential pressure between the oil pressure generated in the oil film on the sliding surface and the oil pressure in the oil passage of the fixed system holding the journal bearing is applied as stress, that is, the periphery of the oil flow passage. As for the parts, the main body is in a state of being reinforced by the convex parts. Therefore, even when repetitive stress due to the differential pressure is applied to the periphery of the through-passage, the strain generated in that portion is suppressed, so that early separation between the rigid member of the journal bearing and the lining is prevented.

[0016]

1 is a diagram showing the structure of a journal bearing 1 according to an embodiment of the present invention. FIG. 1 (A) is a front view thereof, and FIG. 1 (B) is a connecting rod 10 of an internal combustion engine. The example in which the journal bearing 1 is used as the rotary bearing of FIG. 3C is an enlarged view of the main part when the journal bearing 1 is assembled to the connecting rod 10.

Here, as shown in FIG. 1B, the journal bearing 1 is a member that functions as a rotary bearing of the connecting rod 10 of the internal combustion engine, etc. Generally, the journal bearing 1 faces the journal bearing 1. 11
Is provided, and the function as a rotary bearing is secured by these one set.

By the way, the connecting rod 10 is a member that connects the crankshaft and the piston of the internal combustion engine and converts the reciprocating motion of the piston into the rotary motion of the crankshaft, as will be described later, and is the largest among the constituent members of the internal combustion engine. It is one of the members that receive stress.

Therefore, the rotary bearing of the connecting rod 10 must be able to maintain an appropriate sliding resistance under such a large stress. Journal bearing 1,
In order to satisfy such requirements, 11 forms an oil film of lubricating oil on the sliding surface thereof, and the crankshaft and connecting rod 1
It suppresses metal contact in the sliding portion when 0 rotates relatively.

Here, in the journal bearing 1 of this embodiment, as shown in FIG. 1 (A), the outer circumference of the journal bearing 1 is a fixed surface 2 and the inner circumference is a sliding surface 3, and these are used as a rigid member 4 made of iron or the like. The lining 5 made of aluminum or the like is pressed, sintered, or cast. Then, at a predetermined portion of the fixed surface 2, there is provided a cylindrical convex portion 9 having a hole 8 which is integrated with a through hole 6 penetrating the rigid member 4 and the lining 5 and constitutes an oil flow passage 7. There is.

By the way, in the structure in which an oil film is formed on the sliding surface 3 to secure an appropriate sliding resistance, it is necessary to circulate appropriately purified lubricating oil to the sliding surface 3 of the journal bearing 1. If the lubricating oil is stagnant on the sliding surface 3, metal powder or the like generated by sliding will accumulate, or the lubricating oil will run short and sliding heat will accumulate, resulting in a situation where a sufficient lubricating action cannot be obtained. This is because the internal combustion engine may be burned in.

For this reason, when the journal bearing 1 is used to form a rotary bearing, it is essential to provide a mechanism for circulating lubricating oil on the sliding surface 3, and the oil flow passage 7 described above is It constitutes a part of the lubrication path. Then, in the case of the present embodiment, FIG.
In the oil passage 12 provided in the connecting rod 10 as shown in
A configuration is adopted in which the above-mentioned convex portion 9 is inserted to communicate the oil flow passage 7 with the oil passage 12.

The journal bearing 11 shown in FIG.
The oil flow passage 7 and the oil passage 12 of the connecting rod 10 discharge the lubricating oil from the sliding surface 3 side of the journal bearing 1 to the diagonally upper side of the connecting rod 10 to supply oil to other parts inside the internal combustion engine. And constitutes a part of the distribution path of the lubricating oil in the internal combustion engine.

The structure of the lubricating oil flow path in the internal combustion engine using the connecting rod 10 and how the lubricating oil is supplied to the sliding surface 3 of the journal bearing 11 will be briefly described below with reference to FIG. To do.

FIG. 2A is a perspective perspective view of a four-cylinder internal combustion engine 20 in which a piston 21 and a crankshaft 30 are connected by a connecting rod 10. It should be noted that the description of each component shown in the figure is omitted because it is common as a configuration of an internal combustion engine.

As shown by the arrow in the figure, the internal combustion engine 20
The lubricating oil stored in the oil pan formed at the lowest portion of the pump is pumped up by the oil pump 22, flows through the cylinder block, and flows into the oil filter 23.

A passage communicating with the outlet of the oil filter 23 and a passage communicating with the five rotating portions 31a to 31e provided on the crankshaft 30 through a flow passage formed in the cylinder block, and a cam. Shaft 24,
It branches into a passage that circulates around 25.

Here, the crankshaft 30 is shown in FIG.
The rotary parts 31a to 31e at five locations shown in (B) are rotatably held by the cylinder block, and their bearings are journal bearings (not shown) which are oil-filled bearings as in the case of the connecting rod 10. ).

In this case, the oil circulating port provided in the journal bearing functions as a lubricating oil introducing port, and the lubricating oil supplied through the branch pipe branched after the oil filter 23 flows directly to the crankshaft. It will be guided between the rotating parts 31a-31e of 30 and the journal bearing holding these.

By the way, as shown in FIG. 2B, the crankshaft 30 is provided with an oil passage 33a communicating from a predetermined portion on the outer circumference of the rotating portion 31a to a predetermined portion on the outer circumference of the connecting rod connecting shaft 32a. ing. Similarly, the rotating unit 3
An oil passage 33b is provided between the 1b and the connecting rod connecting shaft 32b, and an oil passage 33c is provided between the rotating portion 31d and the connecting rod connecting shaft 32c.
However, an oil passage 33d is provided between the rotating portion 31e and the connecting rod connecting shaft 32d.

For this reason, if the lubricating oil is supplied to the rotating portions 31a to 31e of the crankshaft 30 as described above, the lubricating oil flows through the crankshaft 30 to connect the connecting rod connecting shafts 32a to 32a. It will be appropriately supplied to 32d. The lubricating oil thus supplied forms an oil film between the outer peripheral surfaces of the connecting rod connecting shafts 32 a to 32 d and the journal bearing 1 fixed to the connecting rod 10.

Further, the connecting rod connecting shafts 32a to 32 of the oil passages 33a to 33d provided in the crankshaft 30 are connected.
The d-side opening is open toward the outer circumference of the crankshaft 30. Therefore, the oil passage 1 is located at the position shown in FIG.
When the connecting rod 10 including 2 is combined, the oil passages 33a to 33d communicate with the oil passage 12 of the connecting rod 10 when the connecting rod connecting shafts 32a to 32d reach the vicinity of the top dead center.

Therefore, in the internal combustion engine 20, when the piston 21 of each cylinder is displaced near the top dead center, the lubricating oil is injected from the connecting rod 12 toward the inner wall of the cylinder of each cylinder. The lubricating oil is appropriately supplied to the sliding surface with the cylinder.

In this way, through the oil flow passage 7 provided in the journal bearing 1, every time the connecting rod 10 is displaced near the top dead center, it is necessary to circulate the amount of lubricating oil to be injected to the inner wall of the cylinder. At this time, the opening area of the oil flow passage 7 that determines the injection amount of the lubricating oil to the inner wall of the cylinder is determined by the piston 2
1 is a factor that greatly affects the smoothness, cooling property, etc., and is one of the items required to ensure a predetermined dimension in the assembled state.

By the way, in forming the journal bearing, it is preferable that the area of the through hole opening on the sliding surface is smaller, as described above. As shown in FIG. 3, the member 40 having no hole and the member 40 having no hole are formed. , When comparing the hydraulic pressure distributions formed in the member 42 having the holes 41, the member 4
It is also clear from the fact that the hydraulic pressure distribution formed above 2 is extremely small.

FIG. 4 is a view showing the structure around the through hole 52 of a general journal bearing 51 constructed in view of the above point, and it is necessary that the opening area of the through hole 52 allows a desired flow rate to flow in advance. An example in which the rod is set to the minimum size and assembled to the connecting rod 10 is shown.

In this case, the oil passage 5 provided in the connecting rod 10
If 3 has the same diameter as the through hole 52, theoretically desired lubricating oil can be circulated. But,
When these are configured to have the same diameter, a problem occurs when the mounting position of the journal bearing 51 is deviated as shown by the chain double-dashed line in FIG. Through hole 5 for oil passage 53
This is because No. 2 exerts the function of the orifice and it becomes impossible to obtain a substantially required opening area.

Therefore, when the rotary bearing is constructed by using the journal bearing 51 in which the opening area of the through hole 52 is set to the necessary minimum, as shown in FIG.
A method is generally used in which an oil passage 54 having a diameter larger than that of the through hole 52 is formed in the connecting rod 10 to absorb the assembly tolerance.

If such a construction is adopted, it is possible to reliably inject a desired flow rate of lubricating oil from the oil passage 54 toward the inner wall of the cylinder without extremely improving the processing accuracy of the journal bearing 51 and the connecting rod 10 and the assembly accuracy of both. Piston 21 that can be connected to connecting rod 10
It is possible to secure good lubrication effect and cooling effect in the periphery.

By the way, in the internal combustion engine 20 in which the piston 21 vibrates vertically as shown in FIG. 2, the direction of the stress applied to the connecting portion between the connecting rod 10 and the crankshaft 30 with the vibration of the piston 21 is vertical. Invert periodically.

That is, during the explosive process of the internal combustion engine, the connecting rod 10 pushes down the crankshaft 30, and during the exhausting process, the crankshaft 30 pushes up the connecting rod 10, and during that time, a compressive stress is generated at their connecting portions. Next, when the cylinder shifts to the intake stroke, the crankshaft 30 pulls down the connecting rod 10, and as a result, a tensile stress acts on the connecting portion. Then, in the subsequent compression process, the crankshaft 30 pushes up the piston 21, so that compressive stress acts on the connecting portion again.

Therefore, according to the example shown in FIG. 5, the oil pressure of the oil film 55 formed between the crankshaft 30 and the journal bearing 51 periodically fluctuates as the crankshaft 30 rotates. Becomes At this time, the oil passage 54 provided in the connecting rod 10 is opened to the crankcase internal pressure similarly to the oil passage 12 shown in FIG.
The internal pressure does not change significantly.

As a result, a periodic pressure difference is generated between the oil passage 54 side and the oil film 55 side across the through hole 52 of the journal bearing 51, and the peripheral portion of the through hole 52 corresponds to the pressure difference. As a result, distortion is repeatedly generated.

By the way, in order to achieve both the rigidity and the sliding characteristics required for the journal bearing, a rigid member 4 made of iron or the like and a lining 5 made of aluminum or the like are pressed, sintered or cast to form two layers. As described above, it is effective to use the main body of the structure. However, in such a member having a two-layer structure, peeling may occur at the interface when the strain as described above repeatedly occurs due to the difference in the physical properties of each layer.

Therefore, when the rotary bearing is constructed by using the journal bearing 51 shown in FIG. 5, the lining 5 around the through hole 52 may peel off as shown in FIG. When the lining 5 is peeled off in this way, the portion that was disadvantageous in securing the film pressure of the oil film from the beginning due to the influence of the through hole 52 becomes further unfavorable. Further, if the peeled lining 5 adheres to an inappropriate portion as shown by a broken line in FIG. 6, an appropriate oil film cannot be formed even at that portion.

In this way, as shown in FIG.
The journal bearing 51 which is used by setting the minimum required size is capable of forming a good oil film in the initial state, unlike the one in which the positioning is performed by using the conventional fixing pin, but it is relatively In some cases, the characteristics deteriorated at an early stage.

On the other hand, the journal bearing 1 of this embodiment is provided with the convex portion 9 on the fixed surface 2 as shown in FIG.
The periphery of the through hole 6 is reinforced. Therefore, even when a pressure difference occurs between the oil pressure of the oil film formed on the sliding surface 3 and the oil pressure in the oil passage 12, the strain generated around the through hole 6 is small, and the lining 5 like the journal bearing 51 is used. Peeling does not pose a problem.

Further, the convex portion 9 provided on the fixed surface 2 has a hole 8 forming the oil flow passage 7 therein. Therefore, as shown in FIG. 1C, the oil passage 12 of the connecting rod 10 is
If the configuration in which the convex portion 9 is fitted inside is adopted, if only the processing accuracy of the oil flow passage 7 is properly secured, it will depend on the processing accuracy of other parts and the assembly accuracy of the journal bearing 1 and the connecting rod 10. Instead, it is possible to appropriately flow the desired amount of lubricating oil through the oil passage 12.

Since the journal bearing 1 and the connecting rod 10 can be aligned by fitting the convex portion 9 and the oil passage 12, it is not necessary to provide another positioning member, and the number of parts can be reduced, or It is possible to reduce the number of processing steps, and it is possible to prevent the lining 5 from being damaged due to sliding of a fixing pin or the like, which has been a problem in the past.

As described above, in the journal bearing 1 of the present embodiment, the oil flow passage 7 capable of ensuring a desired lubricating oil flow rate without requiring high processing accuracy and with a good assembling property is formed. In addition, the lining durability can be remarkably superior to that of the conventional journal bearing. That is, according to the journal bearing 1, cost reduction and high durability can be compatible at a high level.

In the journal bearing 1 shown in FIG. 1, the convex portion 9 has a cylindrical shape as shown in FIG. 7A, but the shape is not limited to this. ) And (B) may be used, the protrusions 62 and 72 of a rectangular cylinder shape may be used like the journal bearings 61 and 71 shown, respectively.

As for the convex portion 9, for example, FIG.
As shown in (A), press molding is performed from the inner peripheral side of the journal bearing 1 by using a suitable punch, and as shown in (B) and (C) of the same, by solid phase joining such as pressure welding or by welding. It is possible to form them by fusion bonding such as.

[0053]

As described above, according to the present invention, the convex portion provided on the fixing surface of the journal bearing functions as a positioning member at the time of assembling, and at the periphery of the through hole provided through the main body. It also functions as a reinforcing member.

Therefore, the journal bearing can be easily assembled at an appropriate position by using the convex portion as a reference, and the journal bearing is excellent in the assembling property and forms the oil flow passage which can surely secure a desired lubricating oil flow rate. It is possible to Further, even if stress fluctuations occur around the through hole due to oil pressure fluctuations of the oil film formed on the sliding surface of the journal bearing, the strain generated around the through hole is suppressed by the reinforcing effect of the convex portion, The lining exhibits sufficient durability against peeling.

As described above, the journal bearing according to the present invention is greatly improved in cost, performance and durability as compared with the conventional journal bearing, and realizes a lower cost and a better internal combustion engine. It has the feature of getting.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration and an application example of a journal bearing which is an embodiment of the present invention.

FIG. 2 is a perspective perspective view showing a combination of internal combustion engine configurations in which a rotary bearing is configured using the journal bearing of the present embodiment.

FIG. 3 is a diagram for explaining a difference in hydraulic pressure distribution depending on the presence or absence of holes.

FIG. 4 is a cross-sectional view showing the configuration of a main part of a conventional journal bearing configured by giving priority to securing an oil film area formed on a sliding surface.

FIG. 5: Priority is given to ensuring the area of the oil film formed on the sliding surface,
FIG. 14 is a cross-sectional view showing a configuration of a main part of a conventional journal bearing configured in consideration of an assembly tolerance.

FIG. 6 is a diagram showing a state in which a lining is peeled off due to a strain repeatedly generated around a through hole of a journal bearing.

FIG. 7 is a configuration diagram showing a variation of a journal bearing according to the present invention.

FIG. 8 is a diagram showing a configuration example in which a convex portion, which is a main portion of a journal bearing according to the present invention, is formed by a typical forming method.

[Explanation of symbols]

 1, 61, 71 Journal bearing 2 Fixed surface 3 Sliding surface 4 Rigid member 5 Lining 6 Through hole 7 Oil flow passage 8 Hole 9 Convex portion 10 Connecting rod 12 Oil passage 20 Internal combustion engine 30 Crankshaft

Claims (1)

[Claims] 1. A member that is interposed between a shaft and a housing to reduce sliding resistance when the two relatively rotate, and one surface of the main body is a fixed surface and the other surface is a sliding surface. As a moving surface,
A journal bearing that has a through hole penetrating the body and reduces sliding resistance by forming an oil film on the sliding surface, wherein an oil circulation hole is formed on the fixed surface integrally with the through hole. A journal bearing, which is provided with a convex portion having a hole for