JPH11132221A - Bearing structure for crankshaft of engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the whole length of a crankshaft and lighten weight of a vehicle. SOLUTION: A thrust bearing S is formed by interposing a thrust metal 9 between an upper bearing member 3 holding a crankshaft 1 of the engine from above and the axial face part of a crank journal 2, then the axial width B2 of a lower metal 6 intervening between a lower bearing member 4 of the thrust bearing S and the crank journal 2 is formed wider than the width A1 of a thrust metal abutting face 8 of the upper bearing member 3 of the thrust bearing S. Thus, the length of the bearing of the crankshaft 1 is shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an upper metal and a lower metal for friction reduction interposed between a crank journal of a crankshaft and an upper bearing member and a lower bearing member which rotatably hold the crank journal. And a bearing structure of a crankshaft of the engine.

[0002]

2. Description of the Related Art A conventional bearing structure of a crankshaft 1 will be described with reference to FIG. The crankshaft 1 includes a semicircular upper bearing member (journal receiving portion) 3 in which a plurality of crank journals 2 are formed on a wall of a cylinder block (not shown) and a lower case (not shown). Semicircular lower bearing member (journal receiving part) 4
And is rotatably held by a bearing consisting of

[0003] Between the crank journal 2 of the crankshaft 1 and the upper bearing member 3, as shown in an enlarged view in FIG. The lower metal 6 is interposed between the crank journal 2.

Further, a thrust metal 9 is provided between a metal receiving surface 7 of the crankshaft 1 and a thrust metal contact receiving surface 8 of the upper bearing member 3 for positioning the thrust (axial direction X) of the crankshaft 1. It is interposed.
The thrust metal 9 provides an appropriate clearance in the thrust direction, and the crankshaft 1 rotates smoothly with respect to the thrust metal 9.

[0005] The thrust metal 9 is interposed in one of the upper bearing members 3, the lower bearing member 4 facing the upper bearing member 3, the other upper bearing member 3 and the other lower bearing member 4. No thrust metal 9 is mounted. As a result, the upper bearing member 3 with the thrust metal 9 interposed and the lower bearing member 4 opposed thereto are defined as a thrust bearing S,
Upper bearing member 3 without thrust metal 9 interposed
And the lower bearing member 4 opposed thereto are used as another bearing T.

If the width of the upper metal 5 and the lower metal 6 interposed in the crankshaft 1 in the axial direction X is too small, the bearing surface pressure becomes excessive in the cylinder explosion process, causing seizure. In addition, the bending of the crankshaft 1 during the explosion process is increased, which causes vibration, noise, and the like. For this reason, conventionally, an upper metal 5 and a lower metal 6 having a required width are arranged in each bearing portion.

Therefore, the width B ₀ of the upper metal 5 of the thrust bearing S in the axial direction X must be smaller than the width A of the upper bearing member 3, especially the width A ₀ between the thrust metal contact receiving surfaces 8. That is, it is necessary to _satisfy B ₀ <A ₀ . This is the width A ₀ between the thrust metal contact receiving surfaces 8 of the upper bearing member 3.
This is because even if the width B ₀ of the upper metal 5 is further increased, the upper bearing member 3 does not come into contact with the protruding portion and does not receive a load, which is unnecessary.

Further, the width B _{0 of the} lower metal 6 is set to be smaller than the width C of the lower bearing member 4. This lower metal 6
This is because the minimum size, that is, the width B ₀ is necessary to withstand the load received during the explosion stroke of the crankshaft 1 as described above. The width B ₀ of Roametaru 6, and a width B ₀ of the upper metal 5 in the same width dimension, thereby sharing the parts.

The width of the lower bearing member 4 is C.
The reason is that the thrust metal 9 attached to the upper bearing member 3 is removed.
This is to prevent dropping. This allows the thrust
If the width of the trimetal 9 in the axial direction X is D, the lower bearing member
4 has a width C of A₀ <C <(A ₀ + 2D)
However, here, for example, the thrust metal of the upper bearing member 3
Width A of contact receiving surface 8₀ And the width D of thrust metal 9
It is the same as If this is indicated by a sign,
C = A₀ + D (because D / 2 + D / 2). Ma
The width A of the upper bearing member 3 is also A₀ <A <(A₀ +2
D), and here, for example, a thrust metal contact receiving surface
8 width A₀ And the width D of the thrust metal 9
You. That is, A = A₀ + D. This allows the lower side
The width C of the bearing member 4 and the width A of the upper bearing member 3 are equal. You
That is, C = A.

[0010] Further, as shown in FIG.
Upper bearing member 3 and the lower bearing member 4, since both unaffected by thrust metal 9, the width C of the width A and the lower bearing member 4 of the upper bearing member 3 are both unified A ₀ of the same size . That is, C = A = A ₀ . In addition,
In the case of the crankshaft 1 shown in FIG. 6, all the bearing members 3 and 4 of the other bearings T have the same width as the thrust bearing S. That is, the width is C = A = A ₀ + α (α is an arbitrary value satisfying α ≦ 2D), and the width is a special one elongated in the axial direction.

In FIG. 6, reference numeral 10 denotes a piston, and reference numeral 11 denotes a connecting rod connecting the crankshaft 1 and the piston 10. Reference numeral 12
Indicates a piston pin. Further, reference numeral 13 denotes a pulley fixed to the tip of the crankshaft 1, and reference numeral 14 denotes a chain cover. The reference numeral 15 denotes a timing sprocket provided on the crankshaft 1, the reference numeral 16 denotes a sprocket for an oil pump, and the reference numeral 17 denotes the sprocket 16
This is the pump chain engaged with.

[0012]

In the prior art described above, since the thrust metal is disposed on both sides of the upper bearing member of the thrust bearing, the axial width of the thrust bearing including the thrust metal is reduced. There is a problem that the overall length of the crankshaft becomes longer than that of other bearings not equipped with thrust metal.

Further, in the case of the crankshaft shown in FIG. 6, since the axial width of all the bearing members is the same as the width of the upper bearing member including the thrust metal of the thrust bearing, the overall length becomes longer. I had to make the crankshaft longer. When the crankshaft is lengthened, there is a problem that the shape of the engine becomes large and the weight of the vehicle increases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and has been made to increase the axial width of the lower metal of the thrust bearing, thereby reducing the length of the thrust bearing and other bearings. It is another object of the present invention to provide a crankshaft bearing structure for an engine in which the overall length of the crankshaft is reduced and the weight of the vehicle is reduced.

[0015]

According to the first aspect of the present invention,
A plurality of crank journals of the crankshaft are rotatably held by an upper bearing member and a lower bearing member via an upper metal and a lower metal, and at least one of the bearing members, and In a bearing structure of an engine crankshaft provided with a thrust bearing having a thrust metal contact receiving surface in which a thrust metal is interposed between the lower bearing member and an axial surface portion, an intermediate portion is provided between the lower bearing member and a crank journal. The axial width of the mounted lower metal is formed wider than the width of the thrust metal contact receiving surface of the upper bearing member of the thrust bearing.

The axial width of the lower metal is made larger than the width of the thrust metal contact receiving surface of the upper bearing member of the thrust bearing, thereby improving the durability of the lower metal.
The width of the thrust metal contact receiving surface, including the width of the thrust metal, of the upper bearing member is reduced. That is, when the width of the thrust metal contact receiving surface of the upper bearing member of the present invention is the same as that of the conventional bearing, the durability is increased by the increase in the width of the lower metal. Further, when the width of the lower metal of the present invention and the width of the conventional lower metal are the same, the width of the thrust metal contact receiving surface of the upper bearing member is reduced.

According to a second aspect of the present invention, in the first aspect, the axial width of the upper metal interposed between the upper bearing member of the thrust bearing and a crank journal is set equal to the thrust bearing. The upper bearing member is formed to be narrower than the width of the thrust metal contact receiving surface.

The width of the lower metal in the axial direction is made larger than the width of the thrust metal contact receiving surface of the upper bearing member of the thrust bearing, and the axial direction of the upper metal is larger than the width of the thrust metal contact receiving surface of the upper bearing member of the thrust bearing. The width of the thrust metal contact receiving surface, including the thrust metal width, of the upper bearing member, while reducing the width of the thrust metal or making it approximately the same size as the thrust metal contact receiving surface. Shorten it.

According to a third aspect of the present invention, the axial width of the lower metal interposed between the lower bearing member for holding all the crank journals of the crankshaft from the lower side and the crank journal is reduced. The thrust bearing is formed so as to be wider than the width of the thrust metal contact receiving surface of the upper bearing member, and the axial width of the upper metal interposed between the upper bearing member that holds all the crank journals from above and the crank journal. The upper bearing member is formed to be narrower than the width of the thrust metal contact receiving surface.

The axial width of the lower metal between all the crank journals and the lower bearing member is made larger than the width of the thrust metal contact receiving surface of the upper bearing member of the thrust bearing,
Furthermore, the width of the upper metal between all the crank journals and the upper bearing member is made smaller than the width of the thrust metal contact receiving surface of the upper bearing member of the thrust bearing, or the width of the upper metal is made the same, and the lower metal The durability is improved, the weight is reduced, and the width of the upper bearing member is reduced.

[0021]

FIG. 1 shows an example of an embodiment of the present invention.
2 and FIG. 2, the same members as those in FIGS. FIG. 1 shows a cross section of a thrust bearing S which rotatably holds a crank journal 2 of a crankshaft 1. The thrust bearing S is
A thrust metal 9 for thrust positioning of the crankshaft 1 is disposed on one of a plurality of bearings, each of which holds a plurality of crank journals 2 and includes an upper bearing member 3 and a lower bearing member 4.

The thrust metal 9 is interposed between the thrust metal contact receiving surface 8 of the upper bearing member 3 of the bearing and the axial metal receiving surface 7 of the crankshaft 1, ie, the crank journal 2. The thrust metal 9 provides an appropriate clearance in the thrust direction, and the crankshaft 1 rotates with respect to the thrust metal 9.

The upper bearing member 3 of the thrust bearing S
An upper metal 5 for lubrication is interposed between the crank journal 2 and the crank journal 2. Further, a lower metal 6 for friction reduction is interposed between the lower bearing member 4 of the thrust bearing S and the crank journal 2.

The crankshaft 1 of the lower metal 6
The axial width B ₂ of the upper bearing member 3 of the thrust bearing S is
Is formed wider than the width A ₁ of the thrust metal contact receiving surface 8. That is, a relationship of B ₂ > A ₁ is established.

An axial width B ₁ of the upper metal 5 in the axial direction of the crankshaft ₁ is formed to be smaller than a width A ₁ of the thrust metal contact receiving surface 8 of the upper bearing member 3 of the thrust bearing S. That is, the relationship is B ₁ ≦ A ₁ .

Further, a bearing T other than the thrust bearing S
Have dimensions as shown in FIG. That is, the width B ₂ of the lower metal 6 of the other bearing T is the same as the width B ₀ of the lower metal 6 of the conventional thrust bearing S or the other bearing T shown in FIGS. 7 and 8. The width B ₁ of the upper metal 5 of the other bearing T is the same as the width B ₀ of the upper metal of the conventional thrust bearing S or the other bearing T.

The metal receiving surface 7 of the crankshaft 1
And the connection position with the crank journal 2 (circled Z in FIG. 1)
3) is formed in an R shape as shown in an enlarged manner in FIG. 3, but strictly after a simple curve, as shown in FIG. A cut portion 19 is formed. By this processing, the structure is strengthened by the residual compressive stress (referred to as a deep roll or fillet roll). This structure, a possibility of interference between Roametaru 6 and the crank journal 2 even by increasing the width B ₂ of Roametaru 6 is no longer, it is possible to shorten the dimension of the crank journal 2.

The operation of the embodiment of the present invention is represented by a sign and a numerical value.
explain. That is, in the present invention, B_Two > A₁ ‥‥‥‥ (1) B_Two : Width of lower metal 6 of thrust bearing S, A₁ : Thrust meta of upper bearing member 3 of thrust bearing S
In the prior art, B₀ ≤A₀ ‥‥‥‥ (2) B₀ : Upper metal 5 of conventional thrust bearing S or
Lower metal 6 width A₀ : Thrust of upper bearing member 3 of conventional thrust bearing S
Width of the metal contact receiving surface 8 Here, in the expressions (1) and (2), A₁ = A₀ If
If B_Two > B₀ And B_Two Is large, durability is improved
I do. That is, if A₁ = 20 mm, B_Two 
Exceeds 20mm and B₀ Is 20 mm or less, and B_Two But
B₀ Be larger. Also, in formulas (1) and (2)
And B_Two = B₀ Then A₁ <A₀ And bearing members
Can be shortened. That is, if B_Two 
= 20 mm, A₁ Is less than 20 mm and A₀ Is 2
0 mm or more, A₁ Is A₀ Smaller. Also,
In equations (1) and (2), A₁ ≤A₀ Then
A, A₁ = A ₀ In case of
A₁ <A₀ Then B_Two ≧ B₀ And B_Two Is large
That is, the durability is improved. That is, if A₀ = 20
mm₁ Is less than 20 mm. By this
And B_Two Is B₀ As described above, it becomes larger. B_Two Is B₀ When
If they are the same, the members can be shared with the conventional one.

Further, in the present invention, B ₁ ≦ A ₁ ‥‥‥‥ (3) B ₁ : Width of the upper metal 5 of the thrust bearing S A ₁ : Thrust metal contact receiving surface of the upper bearing member 3 of the thrust bearing S In the prior art, B ₀ ≦ A ₀ ‥‥‥‥ (4) B ₀ : width of the upper metal 5 or lower metal 6 of the conventional thrust bearing S A ₀ : width of the upper bearing member 3 of the conventional thrust bearing S Here, in formulas (3) and (4), if A ₁ = A ₀ , B ₁ and B ₀ are the same, and (3) and (4)
In the equation, if B ₁ = B ₀ , A ₁ and A ₀ become the same, and the members can be shared with the conventional one.
At this time, if B ₁ <B ₀ , A ₁ can be made smaller than A ₀ , and the overall length of the bearing member can be shortened. The case of B ₁ <B ₀ is suitable when the inertial load (not the direct explosion load) is small.

Next, another example of the embodiment of the present invention will be described. This embodiment, as shown in FIG. 5, Roametaru each thrust bearing S width B ₁ in the axial direction of the axial width B ₂ and the upper metal 5 of Roametaru 6 other bearing T other than the thrust bearing S it is obtained by a combined dimension in the width B ₂ and the width B ₁ of the upper metal 5 of 6.

That is, the width B ₂ of the lower metal 6 of the other bearing T is set to a size exceeding the width A ₁ of the thrust metal contact receiving surface 8 of the upper bearing member 3 of the thrust bearing S shown in FIG. B ₂ > A ₁ , and the width B ₁ of the upper metal 5 of the other bearing T is formed to be smaller than the width A ₁ of the thrust metal contact receiving surface 8 of the upper bearing member 3 of the thrust bearing S. . That is, B ₁ ≦ A ₁ . This structure is the same (dimensions) for all the bearing members 3 and 4 for holding the crank journal 2 of the crankshaft 1.

As described above, all the crank journals 2
Width B of the metal 6_Two The thrust of the thrust bearing member 3
Width A of metal contact receiving surface 8₁ If it is wider than
Chi, B _Two > A₁ Then, compared to the conventional,
As in the form, the width B of the lower metal 6_Two Is big,
The durability of the metal 6 is improved and the thrust bearing
Upper bearing member 3 and lower bearing member 4 of S and other bearings T
The width of the crankshaft
The overall length of the shaft 1 can be reduced.

Further, if the width B ₁ of the upper metal 5 of all the crank journals 2 is set to be smaller than the width A ₁ of the thrust metal contact receiving surface 8 of the upper bearing member 3 of the thrust bearing member S, that is, B ₁ If ≦ a _1, as compared with the conventional, it is possible to share the entire crank journal 2 parts condition if B ₁ <B _0, i.e., the width of the upper metal 5 of the thrust bearing S of the present invention B ₁ is
If the width is smaller than the width B ₀ of the upper metal 5 or the lower metal 6 of the conventional thrust bearing S, the total length of all the bearing members 3 and 4 can be reduced.

[0034]

According to the first aspect of the present invention, the axial width of the lower metal of the thrust bearing is made larger than the width of the thrust metal contact receiving surface of the upper bearing member of the thrust bearing.
If the width of the thrust metal contact receiving surface of the upper bearing member of the thrust bearing is the same as the width of the thrust metal contact receiving surface of the upper bearing member of the conventional thrust bearing, the width of the lower metal will be The larger amount can improve the durability of the lower metal.

If the width of the lower metal is the same as the conventional one, the width of the thrust metal contact receiving surface of the upper bearing member of the thrust bearing can be reduced. Thereby, the width of the thrust metal contact receiving surface including the width of the thrust metal can also be reduced, and the overall length of the crankshaft can be reduced.

According to a second aspect of the present invention, the axial width of the lower metal is made larger than the width of the thrust metal contact receiving surface of the upper bearing member of the thrust bearing, and the thrust metal contact receiving portion of the upper bearing member of the thrust bearing is provided. Since the width of the upper metal of the thrust bearing is made smaller than the width of the surface, the width of the lower metal is reduced as long as the width of the thrust metal contact receiving surface of the upper bearing member is the same as that of the conventional one. The larger amount can improve the durability of the lower metal. If the width of the lower metal is the same as that of the conventional one, the width of the thrust metal contact receiving surface of the upper bearing member of the thrust bearing can be reduced. Thereby, the width of the thrust metal contact receiving surface including the width of the thrust metal can be reduced, so that the overall length of the crankshaft can be reduced.

Further, when the width of the upper metal 5 of the thrust bearing S is smaller than the width of the thrust metal contact receiving surface 8 of the upper bearing member 3 of the thrust bearing S, the thrust metal contact receiving surface of the upper bearing member of the thrust bearing S is provided. If the width of the upper thrust bearing is the same as that of the conventional thrust bearing, the width of the upper metal of the thrust bearing and the width of the upper metal or the lower metal of the conventional thrust bearing become the same.

If the width of the upper metal of the thrust bearing is the same as the width of the upper metal or lower metal of the conventional thrust bearing, the width of the thrust metal contact receiving surface of the upper bearing member of the thrust bearing is equal to that of the conventional thrust bearing. And the members can be shared with the conventional one. At this time, if the width of the upper metal of the thrust bearing is smaller than the width of the upper metal or lower metal of the conventional thrust bearing, the width of the upper bearing member including the thrust metal of the thrust bearing can be reduced,
The overall length of the bearing member can be reduced.

According to the third aspect of the present invention, the axial width of the lower metal disposed between all the crank journals and the lower bearing member is made larger than the width of the thrust metal contact receiving surface of the upper bearing member of the thrust bearing. In addition, the width of the upper metal between all the crank journals and the upper bearing member is set to be equal to or less than the width of the thrust metal contact receiving surface of the upper bearing member of the thrust bearing. If the dimensions are the same as those of the conventional one, the durability of all the lower metals can be improved because the width of the lower metal of the present invention is large.

If the width of the lower metal is the same as that of the conventional one, the width of the thrust metal contact receiving surface of the upper bearing member of the thrust bearing becomes smaller than that of the conventional one, and the width of the upper bearing member and the lower side of all the crank journals. The width of the bearing member can be reduced. Thereby, the width of the upper bearing member and the lower bearing member of the thrust bearing, including the width of the thrust metal, and the width of the other upper bearing member and the lower bearing member can be reduced. This, overall,
The total length of the crankshaft can be reduced.

Further, according to the second and third aspects, the weight can be reduced and the cost can be reduced by reducing the size of the upper metal. Furthermore, in claim 3, since the same parts can be applied to all the bearings of the crank journal, the number of parts can be reduced, the weight can be reduced, and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of a thrust bearing of a crankshaft, showing an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of another bearing of the crankshaft, showing the embodiment of the present invention.

FIG. 3 is an enlarged sectional view of a Z portion shown in FIG.

FIG. 4 is a cross-sectional view showing a state where the one shown in FIG. 3 is processed by a roller.

FIG. 5 is an enlarged sectional view of a bearing showing another example of the embodiment of the present invention.

FIG. 6 is a top view for explaining a state of holding a conventional crankshaft.

FIG. 7 is an enlarged sectional view of a conventional thrust bearing of a crankshaft.

FIG. 8 is an enlarged sectional view of another conventional bearing without a thrust of a crankshaft.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Crankshaft 2 Crank journal 3 Upper bearing member 4 Lower bearing member 5 Upper metal 6 Lower metal 8 Thrust metal contact receiving surface 9 Thrust metal A _{1 1} Thrust metal contact receiving surface width B ₁ Upper metal width B ₂ Lower metal width S Thrust bearing

Claims (3)

[Claims] An upper bearing member and a lower bearing member rotatably hold a plurality of crank journals of a crankshaft via an upper metal and a lower metal, and
A crankshaft bearing for an engine having a thrust bearing having a thrust metal contact receiving surface in which a thrust metal is interposed between at least one of the bearing members and an axial surface of the crank journal. In the above structure, the axial width of the lower metal interposed between the lower bearing member and the crank journal is formed to be larger than the width of the thrust metal contact receiving surface of the upper bearing member of the thrust bearing. The bearing structure of the engine crankshaft. 2. The axial width of the upper metal interposed between the upper bearing member of the thrust bearing and the crank journal is larger than the width of the thrust metal contact receiving surface of the upper bearing member of the thrust bearing. 2. The bearing structure for an engine crankshaft according to claim 1, wherein the bearing structure is formed narrow. 3. An axial width of a lower metal member interposed between a lower bearing member for holding all crank journals of a crankshaft from below and a crank journal.
The thrust bearing is formed wider than the thrust metal contact receiving surface of the upper bearing member, and the axial width of the upper metal interposed between the upper bearing member that holds all the crank journals from above and the crank journal is reduced. A bearing structure for an engine crankshaft, wherein the width of the thrust metal contact receiving surface of an upper bearing member of the thrust bearing is formed to be narrower.