JP3518214B2 - Selective mounting method of bearing metal - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for selectively assembling bearing metal, and more particularly to a method for selectively assembling bearing metal suitable for suppressing variations in oil clearance between the bearing metal and the journal. .

[0002]

2. Description of the Related Art Conventionally, in order to rotatably support a shaft, a bearing metal is interposed between the shaft and a bearing portion. For example, a crankshaft of an internal combustion engine is generally rotatably supported by a bearing metal provided between a bearing housing provided in a cylinder block and a journal of the crankshaft. The bearing metal is composed of a member divided into two semicircular shapes. Each member is formed so that its circumferential length is longer than the semicircular shape by a predetermined length. This predetermined length is hereinafter referred to as a crash height. By providing such a crash height, when the bearing metal is assembled to the bearing housing, the bearing metal is compressed and deformed in the circumferential direction by an amount corresponding to the crash height. As a result, the bearing portion is expanded and deformed in the radial direction, and the bearing metal is closely fixed to the bearing portion.

On the other hand, an oil clearance for supplying lubricating oil is provided between the inner peripheral surface of the bearing metal and the journal of the crankshaft. If this oil clearance becomes too large, the crankshaft will rattle,
It causes vibration and noise of the internal combustion engine. Further, if the oil clearance is too small, the rotation resistance of the crankshaft becomes large, which leads to deterioration of the startability of the internal combustion engine and eventually seizure of the crankshaft. Therefore, in order to realize smooth rotation of the crankshaft,
Proper setting of oil clearance is required.

Since the inner diameter of the bearing housing and the outer diameter of the journal of the crankshaft are accompanied by machining errors, the gap between the bearing housing and the journal varies. Therefore, in order to properly set the oil clearance, it is necessary to suppress the variation in the oil clearance by selecting a bearing metal having an appropriate thickness according to the actually measured values of these diameters.

Further, as described above, when the bearing metal is assembled to the bearing housing, the bearing housing expands and deforms in the radial direction. Actual oil clearance when such expansion deformation occurs (hereinafter referred to as actual oil clearance)
Is greater than the designed oil clearance determined by the inner diameter of the bearing portion, the outer diameter of the journal, and the thickness of the bearing metal by the amount of expansion deformation, and variations also occur due to the expansion deformation. Therefore, in order to suppress the variation in the actual oil clearance, it is necessary to consider not only the thickness of the bearing metal but also the amount of expansion and deformation of the bearing housing.

Therefore, for example, Japanese Unexamined Patent Publication No. 8-12843.
In the method of selectively assembling the bearing metal disclosed in No. 5, the bearing metal is selected in consideration of the fact that the expansion deformation amount of the bearing metal changes depending on the size of the crash height. That is, in the above-mentioned conventional method, the thickness of the bearing metal that gives the required actual oil clearance and the crash height are determined based on the measured values of the journal diameters of the cylinder block and the crankshaft, and these predetermined thicknesses are determined. Also, bearing metal having crush height is selected and assembled.

[0007]

However, it is difficult to independently control the thickness and crash height of the bearing metal in the manufacturing process of the bearing metal. Therefore, as in the above-mentioned conventional method of selectively assembling bearing metal, a predetermined thickness, and
If a bearing metal having both predetermined crash heights is selected, only a limited part of the manufactured bearing metal can be used, and the yield of the bearing metal is significantly reduced.

The present invention has been made in view of the above points, and it is possible to suppress the variation in the actual oil clearance between the bearing metal and the journal portion of the shaft without lowering the yield of the bearing metal. It is an object to provide a method of selectively assembling possible bearing metals.

[0009]

The above-mentioned object is defined in claim 1.
In the method for selectively assembling bearing metal, the bearing metal is assembled in the gap between the journal of the shaft and the bearing housing for the journal while expanding and deforming the bearing housing by the interference.
A first step of ranking a plurality of the bearing metals according to their thicknesses in advance, and a tolerance range of the outer diameter of the journal and a tolerance range of the inner diameter of the bearing housing that are at least one rank in advance. A second step of classifying the ranks so that the widths are not uniform and associating the ranks of the bearing metal with the combinations of the ranks, and a third step of actually measuring the outer diameter of the journal and the inner diameter of the housing. And the measured value of the outer diameter of the journal,
And a fourth step of determining which one of the ranks of the tolerance range the measured value of the inner diameter of the housing belongs to, and the rank of the bearing metal associated with the combination of the determined ranks. This is accomplished by a method of selectively assembling bearing metal, which comprises a fifth step and a sixth step of assembling the bearing metal of the determined rank.

In the present invention, at least one of the rank of the tolerance range of the outer diameter of the journal and the rank of the tolerance range of the inner diameter of the bearing housing has an uneven width. By the ranking with the uneven width, the increase in the clearance between the bearing metal and the journal due to the expansion deformation of the bearing housing is absorbed. As a result, variations in oil clearance are suppressed.

Further, as described in claim 2, the above-mentioned object is, in the method of selectively assembling a bearing metal according to claim 1, in the second step, a tolerance range of an outer diameter of the journal, and A tentative ranking step comprising the steps of ranking the tolerance range of the inner diameter of the bearing housing into tentative ranks of uniform width; and associating the bearing metal rank with each combination of the tentative ranks, The clearance between the bearing metal and the journal for each combination of temporary ranks is based on the rank of the bearing metal corresponding to the combination and the expansion deformation amount of the bearing housing associated with the assembly of the bearing metal. A clearance determination step of determining the clearance, and a rank modification step of modifying the temporary rank based on the clearance determined, It is achieved by a method with 択組.

In the present invention, in the clearance determining step, the clearance between the bearing metal and the journal for each combination of the temporary ranks is determined based on the rank of the bearing metal and the expansion deformation amount of the bearing housing. Therefore, at the rank correction stage, the clearance that takes into account the amount of deformation of the bearing housing (hereinafter referred to as the actual clearance)
The provisional rank is corrected based on. This allows
Variations in actual clearance are effectively suppressed.

Further, as described in claim 3, the above-mentioned object is, in the method for selectively assembling bearing metal according to claim 2, in the step of modifying the rank, the combination of the temporary ranks in which the clearance is maximized. This is achieved by a method of selectively assembling a bearing metal, which comprises the step of modifying the temporary rank for at least one of the outer diameter of the journal and the inner diameter of the housing so that a thicker rank of the bearing metal is associated therewith. It

In the present invention, the temporary rank is modified so that the thicker rank of the bearing metal is associated with the combination of temporary ranks that maximizes the actual clearance.
The correction of the provisional rank reduces the maximum value of the actual clearance. Therefore, the difference between the minimum value and the maximum value of the actual clearance, that is, the variation of the actual clearance is reduced.

Further, as described in claim 4, the above-mentioned object is, in the method of selectively assembling bearing metal according to claim 2, in the rank correcting step, the combination of the temporary ranks in which the actual clearance is minimized. A method of selectively assembling a bearing metal, which comprises the step of modifying the temporary rank for at least one of the outer diameter of the journal and the inner diameter of the housing so that a thinner rank of the bearing metal is associated with To be done.

In the present invention, the provisional rank is modified so that the combination of the provisional rank that minimizes the actual clearance is associated with the rank of the thinner bearing metal.
The correction of the temporary rank increases the minimum value of the actual clearance. Therefore, the difference between the minimum value and the maximum value of the actual clearance, that is, the variation of the actual clearance is reduced.

Further, as described in claim 4, the above-mentioned object is, in the method of selectively assembling bearing metal according to claim 2, in the step of modifying the rank, the combination of the temporary ranks that maximizes the clearance is performed. In contrast to the thicker bearing metal ranks being associated with each other, or for the combination of the provisional ranks that minimizes the clearance,
The step of modifying the temporary rank for at least one of the outer diameter of the journal and the inner diameter of the bearing housing so that the thinner rank of the bearing metal is associated with the modified rank is at least a new temporary rank. This is achieved by the method of selectively assembling the bearing metal, which comprises the steps of repeating two or more times.

In the present invention, the provisional rank is such that the combination of the provisional rank that minimizes the actual clearance is associated with the thinner bearing metal rank, or
It is repeatedly corrected so that the rank of thicker bearing metal is associated with the combination of temporary ranks that maximizes the actual clearance. By repeating the temporary rank modification, the minimum value of the actual clearance is increased or the maximum value thereof is decreased. Thereby, the variation in the actual clearance is greatly reduced.

[0019]

1 is a sectional view of a crankshaft 12 of an internal combustion engine 10 in which bearing metal is selectively assembled by a method of selectively assembling bearing metal according to an embodiment of the present invention. As shown in FIG. 1, the crankshaft 12 includes a plurality of journals 14 and a plurality of crankpins 15. The crankshaft 12 is rotatably assembled to the cylinder block 16 by the journal 14 being supported by a plurality of bearing housings 18 provided in the cylinder block 16. A connecting rod 22 connected to a piston 20 is rotatably connected to a crank pin 15 of the crankshaft 12.

FIG. 2 is a sectional view of the bearing housing 18 taken along a plane perpendicular to its axis. As shown in FIGS. 1 and 2, the bearing housing 18 includes a holder 24 formed in the cylinder block 16 and a bearing cap 27 fixed to the holder 24 by a pair of bolts 26.
It is composed of a cylindrical hole defined by and. A bearing metal 28 is interposed in a gap formed between the outer peripheral surface of the journal 14 and the inner peripheral surface of the bearing housing 18. The bearing metal 28 is a cylindrical metal member and is configured by combining a pair of members 28a and 28b that are divided into two semicircular parts.

FIG. 3 is a sectional view showing a state where the member 28a or 28b of the bearing metal 28 is installed in the holder 24 or the bearing cap 27. As shown in FIG. 3, the members 28 a and 28 b forming the bearing metal 28 are the same as the holder 2
4 or the bearing cap 27 in an open state, one end in the circumferential direction thereof is formed to project from the mounting surface of the holder 24 or the bearing cap 27. This protrusion amount is hereinafter referred to as a crash height. That is, the outer peripheral length of the bearing metal 28 is longer than the inner peripheral length of the bearing housing 18 by the sum of the crash heights of the members 28a and 28b. Therefore, the members 28a, 2
When 8b is assembled to the bearing housing 18, the crush height acts as an interference. Therefore, the bearing metal 28 is compressed and deformed outward in the radial direction when it is assembled to the bearing housing 18, whereby the bearing metal 28 is tightly fixed to the bearing housing 18 and the bearing housing 18 has a crash height. Is expanded and deformed in the radial direction in accordance with the size of. Hereinafter, the amount of expansion deformation of the bearing housing 18 associated with the mounting of the bearing metal 28 will be referred to as an assembling expansion amount, and the size thereof will be represented by the amount of increase in the radius of the bearing housing 18. Even if the crush height is constant, if the inner diameter of the bearing housing 18 (hereinafter referred to as the housing diameter) decreases, the action of the crush height as a tightening margin increases. Therefore, as the housing diameter decreases, the assembling expansion amount of the bearing housing 18 increases.

Referring again to FIGS. 1 and 2, an oil clearance C is provided between the inner peripheral surface of the bearing metal 28 and the outer peripheral surface of the journal 14. Lubricating oil is supplied to the oil clearance C through an oil passage 30 provided in the journal 14. As a result, the bearing metal 28 functions as a slide bearing for the journal 14, and the crankshaft 12 is rotatably supported.

If the above-mentioned oil clearance becomes too large, the backlash of the crankshaft becomes large, which causes vibration and noise of the internal combustion engine 10. If the oil clearance becomes too small, the journal 14 and the bearing metal 28 will be
The slip resistance between the internal combustion engine 10 and the internal combustion engine 10 is reduced, and the startability and fuel consumption of the internal combustion engine 10 are reduced.
This will cause inconvenience such as image sticking. Therefore, in order to realize smooth rotation of the crankshaft 12, it is necessary to properly set the oil clearance.

Assuming that the housing diameter is A, the thickness of the bearing metal 28 is t, and the outer diameter of the journal 14 of the crankshaft 12 (hereinafter referred to as the journal diameter) is B, the oil clearance C is C = (A -B-2 · t) / 2. Bearing housing 18, crankshaft 1
Since the second journal 14 or the bearing metal 28 has a dimensional tolerance due to a processing error, the oil clearance C varies. In order to suppress such variations, a method of selectively assembling bearing metal, which is generally called a fitting selection method, is known. According to this fitting selection method, the plurality of bearing metals 28 are divided into a plurality of ranks based on the thickness t in advance, and the housing diameter A
And the tolerance range of the journal diameter B are divided into ranks, respectively, and then the housing diameter A and the crankshaft 1
The journal diameter B of 2 is actually measured, the rank to which the measured values of A and B belong is determined, the optimum bearing metal 28 rank is determined from each determined rank, and the bearing metal 28 belonging to the determined rank is determined. Bearing metal 28 by selecting and assembling it to the bearing housing 18.
By performing the selective assembling, the variation in the oil clearance is suppressed.

However, as described above, the bearing metal 2
When 8 is assembled in bearing housing 18, there is assembly expansion in bearing housing 18. This assembling expansion amount fluctuates depending on the crash height of the bearing metal 28 and the housing diameter A, and such fluctuation also causes variations in the oil clearance C. On the other hand, in the above-mentioned selective fitting method, since the influence of the assembling expansion of the bearing housing 18 is not taken into consideration, the variation in the oil clearance cannot be sufficiently suppressed.

In order to suppress the variation in the oil clearance due to the assembling expansion of the bearing housing 18, it is necessary to select the bearing metal 28 in consideration of the assembling expansion amount. In this case, the assembling expansion amount of the bearing housing 18 changes depending on the crash height, so that the bearing metal 28
It is also conceivable to suppress the variation in the oil clearance due to the assembling expansion of the bearing housing 18 by ranking the oil with respect to both the thickness and the crash height. However, since only a part of the manufactured bearing metal having both the thickness and the crash height within a predetermined range is limited, if such a method is adopted, the yield of the bearing metal 28 is significantly increased. It will decrease.

The method of selectively assembling the bearing metal of this embodiment is as follows.
In the above-described conventional selective fitting method, the tolerance of the housing diameter A or the journal diameter B is appropriately classified in consideration of the assembling expansion amount of the bearing housing 18, without lowering the yield of the bearing metal 28. ,
It is characterized in that variations in oil clearance can be effectively suppressed. As described above, since the method of selectively assembling the bearing metal according to the present embodiment is based on the conventional fitting selection method, first, the fitting selection method will be described with reference to Tables 1 to 4. . According to the conventional fitting selection method, the tolerance ranges of the housing diameter A and the journal diameter B are ranked in a uniform width.

The fitting selection method described below, and
In the bearing metal selection and assembling method of this embodiment, the tolerance range of the housing diameter A is 0 to +16 μm, and the journal diameter B is
Has a tolerance range of 0 to -12 μm, and the housing diameter A and the journal diameter B are measured in units of 1 μm. The bearing metal 28 is divided into five stages of R0 to R4 with a width of 6 μm according to the thickness t, and the rank is increased in order.
The rank of each bearing metal 28 is stamped. The variation of the thickness t of the bearing metal 28 within each rank is ± 4 μm.

Table 1 is a table for selecting the rank of the bearing metal 28 according to each rank of the housing diameter A and the journal diameter B. In Table 1, the vertical direction indicates the housing diameter A, and the horizontal direction indicates the journal diameter B. Table 1
As shown in, the tolerance range of the housing diameter A and the journal diameter B are both 2 μm width, and 8 steps of 0 to 7, respectively.
The bearing metal 28 is associated with each rank combination.

When the bearing metal 28 is selected, the respective ranks are obtained from the measured values of the housing diameter A and the journal diameter B, and the rank of the bearing metal 28 is determined from Table 1 using these ranks. For example, when the tolerance of the housing diameter A is 7 μm or more and less than 8 μm (rank “3”) and the tolerance of the journal diameter B is more than −9 μm and −8 μm or less (rank “4”), as shown by the dotted line in Table 1, The bearing metal 28 has a rank of R2. Generally, when the sum of the rank for the housing diameter A and the rank for the journal diameter B is r, 0 ≦ r ≦ 2: Rank R0; 3 ≦ r ≦ 5: Rank R1; 6 ≦ r ≦ 8: rank R2; 9 ≦ r ≦ 11: rank R3; r = 12: rank R4;

[0031]

[Table 1]

Tables 2 and 3 show the design calculated based on the housing diameter A, the journal diameter B, and the thickness t of the bearing metal 28 when the bearing metal 28 rank is selected according to Table 1. The oil clearance, that is, the oil clearance (hereinafter referred to as the design oil clearance) that does not consider the assembling expansion of the bearing housing 18 is shown in the unit of μm. Tables 2 and 3 show the values in the respective ranks of the bearing metal 28 when the thickness is the maximum and the minimum within the tolerance range. As mentioned above
The thickness variation of bearing metal 28 within each rank is ± 4
Since it is μm, there is a difference of 8 μm in design clearance between Table 2 and Table 3 for the same combination of housing diameter A and journal diameter B. The bearing metal 28 ranks shown in Table 1 are associated with each other so that the design oil clearances fall within predetermined ranges. That is, in the present embodiment, the ranks in Table 1 are associated with each other, as shown in Tables 2 and 3, where the design oil clearance is 6 to 12 μm on the lower limit side and 14 to 2 on the upper limit side.
The thickness is set to 0 μm.

In the rightmost columns of Tables 2 and 3, the assembling expansion amount of the bearing housing 18 for each housing diameter A is shown in μm. Here, Table 2 shows the values when the crash height of the bearing metal 28 is the minimum (that is, the amount of expansion of the bearing housing 18 is minimum), and Table 3
Has the highest crash height (ie bearing housing 1
8 shows the value when the assembly expansion amount is 8).

[0034]

[Table 2]

[0035]

[Table 3]

As described above, the rank of the bearing metal 28 can be obtained from the sum of the rank of the housing diameter A and the rank of the journal diameter B. Therefore, in the process of assembling the internal combustion engine 10, when assembling the bearing metal 28, without referring to Table 1,
The rank of the bearing metal 28 can be selected.

As shown in Tables 2 and 3, the amount of expansion deformation of the bearing housing 18 decreases with an increase in the housing diameter A, and 10.50 to 8.50 for the bearing metal 28 having the minimum crash height. 00 μm, and 12.50 for the bearing metal 28 with the highest crash height.
It is about 10.00 μm. As described above, even if the housing diameter A is the same, the expansion deformation amount of the bearing housing 18 changes by 2 μm due to the variation of the crash height.

When assembly expansion occurs in the bearing housing 18, the oil clearance increases by the assembly expansion amount. Therefore, the actual oil clearance is a value obtained by adding the assembly expansion amount to the design oil clearance. The oil clearance when the assembly expansion amount is generated is hereinafter referred to as an actual oil clearance. The actual oil clearance values corresponding to Tables 2 and 3 are shown in Tables 4 and 5, respectively. Tables 4 and 5 show the respective values of the design clearances in Tables 2 and 3 plus the corresponding amount of assembling expansion. Therefore, Table 4 shows the lower limit of the actual oil clearance within the tolerance range of the thickness of the bearing metal 28 and the crash height, and Table 5 shows the upper limit of the actual oil clearance. As can be seen from Table 4 and Table 5, according to this fitting selection method, the minimum value of the actual oil clearance is 14.17 μm in Table 4.
The maximum value of the actual oil clearance is 32.33 μm in Table 5. Therefore, the variation of the actual oil clearance, that is, the difference between the maximum value and the minimum value is 18.16 μm.

[0039]

[Table 4]

[0040]

[Table 5]

The method of selectively assembling the bearing metal according to the embodiment of the present invention is to divide the tolerance range of the housing diameter A into ranks with unequal widths in the above-mentioned conventional selective fitting method. Hereinafter, the method of selectively assembling the bearing metal according to this embodiment will be described. Table 6 is a table for selecting the rank of the bearing metal 28 from the combination of the housing diameter A and the journal diameter B in this embodiment, and corresponds to Table 1. Further, Tables 7 and 8 are tables showing the design clearance for each combination of the housing diameter A and the journal diameter and the amount of assembly expansion for each housing diameter A when the rank of the bearing metal 28 is selected according to Table 6. Yes, and corresponds to Table 2 and Table 3, respectively. Tables 9 and 10 show actual oil clearances for each combination of the housing diameter A and the journal diameter B, and correspond to Tables 4 and 5, respectively. As shown in Tables 6 to 10, in this embodiment, the width of the ranks "3" and "5" of the housing diameter A is 3 μm.

[0042]

[Table 6]

[0043]

[Table 7]

[0044]

[Table 8]

[0045]

[Table 9]

[0046]

[Table 10]

As can be seen from Tables 9 and 10, in this embodiment, the minimum value of the actual oil clearance is 15.50 μm, as compared with the case of the above-mentioned conventional selective assembly method shown in Tables 4 and 5. The maximum value is 32.3.
The actual oil clearance variation is reduced to 16.83 μm. The reason why such variation is suppressed is as follows.

That is, as described above, in this embodiment,
For housing diameter A, the width of ranks "3" and "5" has been increased to 3 μm. Therefore, in a region where the tolerance of the housing diameter A is 8 μm or more, the rank of the selected bearing metal 28 is lowered, and the thickness of the bearing metal 28 is reduced. The reduction in the thickness of the bearing metal 28 compensates for the reduction in the amount of expansion of the assembling in accordance with the increase in the housing diameter A, thereby suppressing the variation in the actual oil clearance.

As described above, in this embodiment, the variation in the actual oil clearance is suppressed only by changing the ranking of the housing diameter A. That is,
According to the method of selecting and assembling the bearing metal of this embodiment, when the bearing metal 28 is selected, the dimensions other than the thickness such as the crash height are not limited, and therefore the bearing metal 28 is
It is possible to suppress variations in the actual oil clearance without lowering the yield of oil.

In this embodiment, the ranks "7" are eliminated by increasing the widths of the ranks "3" and "5" with respect to the housing diameter A, and the bearing metal is accordingly removed. The 28 rank R4 has also been eliminated. As described above, according to the bearing metal selective assembling method of the present embodiment, the number of ranks of the bearing metal 28 is reduced from 5 to 4, so that the management based on the thickness of the bearing metal 28 is simplified. At the same time, it is possible to obtain an advantage that the possibility of selecting the bearing metal 28 of the wrong rank is reduced.

Also in this embodiment, the sum r of the rank for the housing diameter A and the rank for the journal diameter B, and the rank of the bearing metal 28 corresponding to each combination, as in the above-mentioned conventional selective fitting method. The relationship with is: 0 ≦ r ≦ 2: Rank R0; 3 ≦ r ≦ 5: Rank R1; 6 ≦ r ≦ 8: Rank R2; 9 ≦ r ≦ 11: Rank R3; Has become. Therefore, when selectively assembling the bearing metal 28, the sum r of the respective ranks is referred to without referring to Table 6.
It is possible to easily select the rank of the bearing metal 28 by determining

By the way, in order to suppress the variation in the actual oil clearance, it is conceivable to reduce the rank width of the housing diameter A or the journal diameter B to 1 μm. Tables 11 to 14 show the cases where the housing diameter A and the journal diameter B are divided into ranks each having a width of 1 μm. Tables 11 to 14 are tables corresponding to Tables 2 to 5, respectively.

[0053]

[Table 11]

[0054]

[Table 12]

[0055]

[Table 13]

[0056]

[Table 14]

As shown by the broken lines in Tables 13 and 14, the minimum value and the maximum value of the actual oil clearance are, respectively.
It is 14.00 μm and 31.50 μm. As described above, by reducing the rank division width to 1 μm, the variation in the actual oil clearance is 18. compared to the case where the rank division is performed with the 2 μm width shown in Tables 4 and 5.
It decreased from 16 μm to 17.50 μm.

As described above, by reducing the rank width of the housing diameter A and the journal diameter B to 1 μm, it is possible to reduce the variation in the actual oil clearance. However, when the rank width of the tolerance range is reduced, the number of ranks increases. Bearing housing 1
8 and crankshaft 12 have a machining accuracy of more than 10 μm, so the rank width is 1 μm.
Then, for the housing diameter A and the journal diameter B, the rank numbers are both two digits. In the cases of Tables 7 to 10, the rank numbers of the housing diameter A and the journal diameter B are 15 and 11, respectively.

In general, when selectively assembling the bearing metal 28, the operator memorizes the respective ranks determined for the measured values of the housing diameter A and the journal diameter B.
By inputting this rank to the bearing metal management computer, the bearing metal of a predetermined rank is taken out. In this case, for example, in the four-cylinder type internal combustion engine 10 shown in FIG. 1, since there are five bearing portions for the crankshaft 12, the operator has five sets for each rank of the housing diameter A and the journal diameter B. Must be remembered. Therefore, if the ranks of the housing diameter A and the journal diameter B are two digits, the numerical value that the operator should store is 10 digits (2 digits) for each rank.
(Digits × 5 places), which makes it difficult to store at once. Further, when the number of ranks becomes two digits, for example, when a digit loss occurs such that the place where the rank is "12" is mistakenly read as "2", the rank of the selected bearing metal 28 shifts to the lower rank side, There is also a problem that the actual oil clearance is greatly expanded.

On the other hand, in this embodiment, 2 μ
The number of ranks of the housing diameter A and the journal diameter B is not increased, and the number of ranks of the housing diameter A is rather reduced, as compared with the above-mentioned conventional selective fitting method in which the ranks are divided by m width. Further, the variation in the actual clearance in this embodiment is 1 μm in the above-mentioned conventional selective fitting method.
It is small compared to the case of ranking by width. As described above, according to the method of selectively assembling the bearing metal according to the present embodiment, the actual oil clearance can be suppressed to be small while avoiding that the rank numbers of the housing diameter A and the journal diameter B have two digits. It is possible.

Next, the procedure for deriving the above Table 6 will be described. As described above, the method of selectively assembling the bearing metal according to the present embodiment is based on the above-described conventional selective fitting method so that the variation in the actual oil clearance, that is, the difference between the minimum value and the maximum value is minimized. The width of the rank division of the tolerance range of the housing diameter A is corrected. Therefore, the derivation of Table 6 is performed based on Tables 4 and 5 in which the minimum value and the maximum value of the actual oil clearance in the above-mentioned selective fitting method are shown. In addition, in this embodiment, the variation of the actual oil clearance is suppressed by correcting the rank classification so that the minimum value of the actual oil clearance, that is, the minimum value in Table 4 is increased.

First, in Table 4, the minimum value of the actual oil clearance is 14.17 μm as shown by the dotted line frame in the table. The minimum value of the actual oil clearance is corrected by lowering the rank of the corresponding bearing metal 28 from R4 to R3, that is, the rank of the housing diameter A is expanded so that the width of the rank “6” is increased by 1 μm. Can be increased. The results of performing such rank modification on Tables 4 and 5 are shown in Tables 15 and 16, respectively.

[0063]

[Table 15]

[0064]

[Table 16]

In Table 15, the minimum value 1 in Table 4
The value corresponding to 4.17 μm increased to 20.17 μm,
Instead, as shown by the broken line frame in the table, 14.50 μm
Is the minimum value. On the other hand, in Table 16, the maximum value of the actual oil clearance is 32.33 μm, which is unchanged from the maximum value in Table 5. Therefore, the variation of the actual oil clearance is 1 in the case of Table 4 and Table 5.
This means a decrease from 8.16 μm to 17.83 μm.

Further, similarly, the minimum value 1 in Table 15 is
Corresponding bearing metal 2 to increase 4.50 μm
To reduce the rank of 8, lower the housing diameter A
Modify so that the width of rank "5" expands by 1 μm to the increasing side. Tables 17 and 18 show the results of performing such rank modification on Tables 15 and 16, respectively.

[0067]

[Table 17]

[0068]

[Table 18]

In Table 17, the value corresponding to the minimum value of 14.50 μm in Table 15 is increased to 20.50 μm, and instead, 14.83 μm is the minimum value. On the other hand, the maximum value of the actual oil clearance in Table 18 is 32.33 μm, which is unchanged from the maximum value in Table 16. Therefore, the variation in the actual oil clearance is 17.50 μm, which is further reduced from the cases of Tables 15 and 16.

As described above, "the minimum value of the housing diameter A is reduced so that the rank of the bearing metal 28 corresponding to the minimum value of the actual oil clearance is lowered by one rank, that is, the thickness of the bearing metal 28 is reduced. The width of the rank one below the corresponding rank is expanded by 1 μm toward the increasing side. ”
When the rank correction process is repeated four times with respect to Tables 17 and 18, Tables 9 and 10 described above are obtained,
Therefore, Table 6 is obtained.

By the above rank modification, the table on the lower limit side of the actual oil clearance (Tables 4, 9, 15 and 1)
If the minimum value of 7) is increased, the upper limit side table (Table 5, 1)
0, 16, 18) also increases sequentially from the minimum value side in the table. Therefore, if the above rank correction is repeatedly performed, a value eventually increases in the table on the upper limit side after the rank correction matches or exceeds the maximum value before rank correction. Under such a situation, the variation of the actual oil clearance cannot be reduced by the rank correction, or rather, it will be increased.

For example, when the same rank modification process is applied to Tables 9 and 10, Tables 19 and 20 are obtained.
The minimum value of actual oil clearance in Table 19 is 15.
67 μm, which is a further increase compared to Table 9, but Table 20
Since the maximum value at is also increased to 32.50 μm,
The variation does not change to 16.83 μm, and if the rank correction process is further repeated, the variation will rather increase. In order to avoid such a situation and suppress the variation in the actual clearance to the minimum, the rank correction process may be ended immediately before the situation as described above occurs.

[0073]

[Table 19]

[0074]

[Table 20]

Although the rank width is modified so that the minimum value of the actual oil clearance is increased in the above embodiment, the present invention is not limited to this, and the maximum value of the actual oil clearance is not limited to this. It may be modified so that the value increases. Further, instead of modifying the rank width for the housing diameter A, the rank width may be modified for the journal diameter B, or the rank width may be modified for both the housing diameter A and the journal diameter B. .

Tables 21 and 22 refer to Tables 4 and 5, respectively, in order to increase the housing diameter A corresponding to the maximum value of the actual oil clearance by one rank. Increase the width of the rank one rank higher than the corresponding rank by 1 μm toward the reduction side. ”Rank correction processing is repeated several times, and the shift of the center of variation in actual oil clearance due to the repetition of such rank correction processing is corrected. In order to do so, bearing metal 2 of each rank
8 shows the result of increasing the thickness of No. 8 by 4 μm. The minimum value in Table 21 is 14.17 μm, and the maximum value in Table 22 is 30.83 μm. Therefore, the variation of the actual oil clearance due to the above rank modification is 18.16 μm to 1 as compared with the cases in Tables 4 and 5.
This means that it has been reduced to 6.66 μm. Also, Table 2
As can be seen from Table 1 and Table 22, according to this rank modification, the rank R0 of the bearing metal 28 is unnecessary, and the number of ranks of the bearing metal 28 is reduced by one as in Tables 9 and 10. There is.

[0077]

[Table 21]

[0078]

[Table 22]

Further, Tables 23 and 24 show that, with respect to Tables 4 and 5, "the minimum of the journal diameter B is set so that the rank of the bearing metal 28 corresponding to the minimum value of the actual oil clearance is lowered by one rank. The result of performing the rank modification process of "increasing the width of the rank immediately below the rank corresponding to the value by 1 μm" is shown. With this rank modification, as shown in Table 23, the minimum value of the actual oil clearance is increased to 14.50 μm, while as shown in Table 24,
The maximum value increases to 33.00 μm. As a result,
In Tables 23 and 24, the variation in the actual oil clearance increases to 18.50 μm.

[0080]

[Table 23]

[0081]

[Table 24]

Here, when the housing diameter A is rank-corrected to reduce the increased maximum value, Tables 25 and 26 are obtained. As shown in Table 25,
While the minimum value is maintained at 14.50 μm, Table 26
The maximum value is reduced to 32.33 μm as shown in FIG.
This maximum value is the same as the maximum value shown in Table 5. Therefore,
The variation of the actual oil clearance is reduced from 18.16 to 17.83 μm as compared with the cases of Table 4 and Table 5. As described above, by correcting the rank of the journal diameter B and the rank of the housing diameter A, it is possible to reduce the variation in the actual oil clearance.

[0083]

[Table 25]

[0084]

[Table 26]

In Table 25, since the minimum value of 14.50 μm belongs to the lowest rank of the journal diameter B, the rank correction for the journal diameter B cannot be performed any more. Therefore, when the rank correction is performed on Tables 25 and 26 so that the minimum value of the actual oil clearance increases for the housing diameter A, Tables 27 and 28 are obtained.

As shown in Table 27, the minimum value of the actual oil clearance is increased to 14.83 μm. On the other hand, Table 2
As shown in FIG. 8, the maximum value is maintained at 32.33 μm. Therefore, the actual oil clearance variation is shown in Table 25.
And compared with the case of Table 26, from 17.83 μm to 17.
It is reduced to 50 μm. In Table 27, the minimum value of 14.83 μm does not belong to the lowest rank of the journal diameter B, so the rank correction for the journal diameter B can be performed again. Hereinafter, similarly, journal diameter B
Alternatively, it is possible to successively reduce variations in the actual oil clearance by repeating rank correction for the housing diameter A as appropriate.

[0087]

[Table 27]

[0088]

[Table 28]

Another embodiment of the present invention will be described with reference to Tables 29 to 33. Tables 29 to 33 correspond to Tables 6 to 10 of the above embodiment. As shown in Tables 29 to 33, in the present embodiment, the housing diameter A and the journal diameter B are 3 μm in the conventional selective fitting method.
Housing diameter A based on the case of ranking by width
Are ranked according to the uneven width of 3 μm and 4 μm.
However, the rank “4” is limited to the upper limit of the tolerance and has a width of 2 μm.

[0090]

[Table 29]

[0091]

[Table 30]

[0092]

[Table 31]

[0093]

[Table 32]

[0094]

[Table 33]

Further, Table 34 and Table 35 show the lower limit value and the upper limit value of the actual clearance by the selective fitting method using the rank width of 3 μm which is the basis of this embodiment. Tables 32 and 33 according to this embodiment are Table 34 and Table 3.
5 is obtained by repeating the rank correction as described above.

[0096]

[Table 34]

[0097]

[Table 35]

As shown in Table 34 and Table 35, rank width 3
In the conventional selective fitting method of μm, the minimum value of the actual clearance is 14.00 μm, the maximum value is 33.17 μm, and the variation thereof is 19.17 μm. On the other hand, according to the method of the present embodiment, the minimum value of the actual clearance is 14.83 μm and the maximum value is 32.50 μm as shown in Tables 32 and 33, and the variation is 17.67 μm.
m compared to the case of the conventional selective fitting method.
Further, the number of ranks of the bearing metal 28 is also reduced from 5 ranks to 4 ranks as compared with the conventional selective fitting method.

As described above, the rank of the bearing metal 28 is selected based on the sum of the ranks of the housing diameter A and the journal diameter B. In this embodiment,
By increasing the rank widths of the housing diameter A and the journal diameter B, the rank numbers of the housing diameter A and the journal diameter B are reduced to 5 and 3, respectively. Therefore, in this embodiment, the sum of the ranks of the housing diameter A and the journal diameter B is 8, which is at most one digit, and the calculation of the sum is extremely simple. As described above, in the present embodiment, the calculation of the sum of each rank is simplified, thereby suppressing the possibility of selecting the bearing metal 28 of the wrong rank.

[0100]

As described above, according to the first and second aspects of the present invention, it is possible to suppress variations in the actual clearance between the bearing metal and the journal. According to the third aspect of the present invention, it is possible to increase the minimum value of the actual clearance between the bearing metal and the journal, which can suppress the variation in the actual clearance.

According to the invention described in claim 4, the maximum value of the actual clearance between the bearing metal and the journal can be reduced, and thus the variation in the actual clearance can be suppressed. Further, according to the invention of claim 5, it is possible to more effectively suppress the variation in the actual clearance between the bearing metal and the journal.

[Brief description of drawings]

FIG. 1 is a diagram showing a crankshaft of an internal combustion engine in which a bearing metal is selectively assembled by a bearing metal selective assembly method according to an embodiment of the present invention.

2 is a cross-sectional view of the bearing portion of FIG.

FIG. 3 is a diagram for explaining a crash height of a bearing metal.

[Explanation of symbols]

14 journals 18 Bearing housing 28 Bearing metal

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B23P 19/00-21/00 F16C 35/00-43/08

Claims (5)

(57) [Claims] 1. Bearing metal is provided in the gap between the journal of the shaft and the bearing housing for the journal.
In a method of selectively assembling a bearing metal to be assembled while expanding and deforming the bearing housing by a tightening margin, a first step of ranking a plurality of the bearing metals according to their thicknesses in advance; At least one of the tolerance range of the diameter and the tolerance range of the inner diameter of the bearing housing
A second step of classifying the ranks so that the widths are not uniform and associating the ranks of the bearing metal with each combination of the ranks, and a third step of actually measuring the outer diameter of the journal and the inner diameter of the housing. And a fourth step of determining to which of the ranks of the tolerance range the measured value of the outer diameter of the journal and the measured value of the inner diameter of the housing belong, respectively, and the combination of the determined ranks. And a sixth step of assembling the bearing metal of the determined rank, and a sixth step of assembling the bearing metal of the determined rank. 2. The method of selectively assembling a bearing metal according to claim 1, wherein the second step comprises a tolerance range of an outer diameter of the journal,
And a tentative ranking step comprising the steps of: classifying the tolerance range of the inner diameter of the bearing housing into tentative ranks of equal width; and associating the bearing metal rank with each combination of the tentative ranks. A clearance between the bearing metal and the journal corresponding to each combination of the temporary ranks, a rank of the bearing metal associated with the combination, and a clearance of the bearing housing associated with the assembly of the bearing metal. A method for selectively assembling a bearing metal, comprising: a clearance determining step that is determined based on an expansion deformation amount; and a rank modifying step that modifies the temporary rank based on the determined clearance. 3. The method of selectively assembling a bearing metal according to claim 2, wherein in the rank correction step, a thicker rank of the bearing metal is associated with a combination of the temporary ranks that maximizes the clearance. As described above, the method for selectively assembling bearing metal comprises the step of correcting the temporary rank for at least one of the outer diameter of the journal and the inner diameter of the bearing housing. 4. The method of selectively assembling a bearing metal according to claim 2, wherein, in the rank correction step, a thinner rank of the bearing metal is associated with a combination of the temporary ranks that minimizes the clearance. As described above, the method for selectively assembling bearing metal comprises the step of correcting the temporary rank for at least one of the outer diameter of the journal and the inner diameter of the housing. 5. The method of selectively assembling bearing metal according to claim 2, wherein in the rank modifying step, a thicker rank of the bearing metal is associated with a combination of the temporary ranks that maximizes the clearance. Or at least one of the outer diameter of the journal and the inner diameter of the bearing housing so that a thinner rank of the bearing metal is associated with the combination of the temporary ranks that minimizes the clearance. A method of selectively assembling a bearing metal, comprising the step of correcting the temporary rank and repeating the corrected rank as a new temporary rank at least twice or more.