JPH05192846A - Method for controlling and machining fitting clearance of assembly - Google Patents

Abstract

PURPOSE:To manufacture components of high assembling precision at low manufactur ing cost by making full use of dimensional tolerance permitted to each of two kinds of assemblies, and performing machining in such a way as to always make the clear ance between annular fitting portions as small as possible without performing selective fitting. CONSTITUTION:To produce two kinds of assemblies 1, 2 in large quantities, when the annular mutually fitting portions 1a, 2a of the assemblies are machined the diameters yR, yL of the machined annular fitting portions of the initially machined assemblies are measured and the differences xR, xL between said diameters after machining and the normal size upper and lower limit center diameters RH, LH, to which tolerance is added, of the annular fitting portions are calculated. The clearance (y) between the measured diameters after machining is calculated and the difference (c) between the clearance (y) and a clearance standard median (z) is calculated and when the difference (c) exceeds a predetermined value P, the differences xR, xL are compared with each other and the diameter to be machined of the assembly with the larger difference is corrected by a predetermined amount AR or AL and subsequent machining of the assemblies 1, 2 is carried out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for mass-production of two types of assembly parts to be assembled with each other, and for performing cutting processing of annular fitting parts of the assembly parts which are fitted to each other. The present invention relates to a suitable fitting clearance control processing method for an assembled component.

[0002]

2. Description of the Related Art As two types of assembly parts in which annular fitting parts are fitted to each other and assembled with each other, for example, as shown in FIG. 4, a right side part 1 and a left side part for constituting a differential gear case for an automobile. In the case of mass-producing such parts 1 and 2, when the annular fitting parts 1a and 2a are cut, N which is conventionally set only for the right part 1 is used.
A C machine tool, for example, an NC lathe, is controlled as shown in FIG. 5A to machine the right side component 1 one after another, and an NC machine tool, for example N
A method has been adopted in which the C-lathe is controlled as shown in FIG. 5B to process the left side component 2 one after another.

In the control shown in FIG. 5 (a), the size increase / decrease range within a predetermined amount from the center diameter R _H of the upper and lower limits of the normal size of the annular fitting portion 1a of the right part 1 is added in advance. The predetermined amount P _R is set as the correction unnecessary range, and the magnitude of the correction amount is set to, for example, the predetermined amount P _R.
It has set up approximately equal value A _R, the first step 11
Then, the NC lathe dedicated to the right side component 1 is machined to machine the annular fitting part 1a of the right side part 1 based on a predetermined machining program, and then in step 12, the inner diameter y of the annular fitting part 1a of the right side part 1 is machined. _R is measured, and in the following step 13, the inner diameter y after processing
Central diameter R of the dimensional tolerance of the annular fitting portion 1a of the right component 1 from _{R
When H} is subtracted, the correction unnecessary range set amount P _R is further subtracted from the obtained value to determine whether or not the result of the calculation is positive. If the result is positive, the inner diameter y _R after machining is out of the correction unnecessary range. Since it is out of the positive direction, in step 14, the correction amount is
After giving it to the NC lathe dedicated to the right side component 1 as A _R ,
Returning to step 11, the next right part 1 is processed.

On the other hand, if the result of the calculation in step 13 is not positive, in step 15, the center diameter R _H of the dimensional tolerance of the annular fitting portion 1a of the right side component 1 is subtracted from the processed inner diameter y _R. the determined values the correction unnecessary range set amount P _R
In addition, it is determined whether or not the result of the calculation is negative. If it is negative, the inner diameter y _R after machining is out of the correction unnecessary range to the negative side. Therefore, in step 16, the correction amount is + A _R As a result, it is given to the NC lathe dedicated to the right side component 1, and then the process returns to step 11 to process the next right side component 1. If the result of the calculation in step 15 is not negative, the inner diameter y _R after machining is within the correction unnecessary range. Therefore, in step 17, the correction amount is set to 0 (not corrected) and the NC for the right-side component 1 is used. After feeding to the lathe, return to step 11.

Therefore, according to the above control, the NC lathe can cut the annular fitting portion 1a of the right side component 1 so as to keep the dimension after machining within the correction unnecessary range, and the left side component 2 Also when cutting the annular fitting part 2a,
As shown in FIG. 5 (b), the annular fitting portion is previously prepared.
The dimensional increase / decrease range within a predetermined amount from the center diameter L _H of the upper and lower limits of the normal dimension of 2a, which is a tolerance, is set as the correction unnecessary range, and the predetermined amount P _L is set. A value A _L that is approximately equal to the predetermined amount P _L is set, and in steps 21 to 27, the NC lathe set for the left-side component 2 only is set based on the processed inner diameter y _L in the same manner as in the case of the right-side component 1 above. Control.

[0006]

By the way, the right side component 1
A dimensional tolerance of about 35 to 45 μ is allowed between the inner diameter of the annular fitting portion 1a and the outer diameter of the annular fitting portion 2a of the left-side component 2, while maintaining high assembly accuracy. Therefore, it is necessary to set the fitting clearance to 10 to 20 .mu., And the fitting clearance cannot be guaranteed if the parts 1 and 2 processed with the above dimensional tolerances are fitted as they are.

For this reason, conventionally, the dimensions within the tolerance of the annular fitting portions 1a, 2a are divided into ranks, and the dimensions of the annular fitting portions 1a, 2a after cutting are measured, respectively. The parts 1 and 2 are assigned to the corresponding ranks, and the parts 1 and 2 are selectively fitted based on the combination of the ranks so as to obtain the fitting clearance described above. Since there is a problem in that the number of steps is increased when the fitting is performed, there is a problem that the manufacturing cost of those parts becomes high.

In order to eliminate the above-mentioned selective fitting, it is conceivable to further narrow the dimensional tolerance and grind the annular fitting portions 1a and 2a in order to fit within the tolerance.
The grinding process has a problem that the equipment cost is higher than that of the cutting process and the time required for processing each piece is long, so that the manufacturing cost of the component is eventually increased.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a machining method which advantageously solves the above-mentioned problems of the conventional machining method, and to control the fitting clearance of the assembly parts of the present invention. In the case of mass-producing two types of assembled parts to be assembled with each other, the processing method is to perform the cutting process of the annular fitting portions of the assembled parts to be fitted with each other, respectively, in the case of the previously cut assembly. The diameter of the annular fitting portion of the attached component after processing is measured, respectively, and the difference between the measured diameter after processing and the diameter of the annular fitting portion, which is the upper and lower limit of the normal dimension including tolerance, is calculated. Obtained, respectively, the fitting clearance between the measured post-processing spans, further, the difference between the obtained fitting clearance and the center value of the clearance standard, the fitting clearance and the clearance obtained Standard center When the difference between the calculated value and the specified value exceeds the specified value, the diameter to be processed is corrected by a specified amount for the part with the larger difference between the obtained diameter after machining and the tolerance center diameter, and the subsequent cutting of the component It is characterized by performing processing.

[0010]

According to this method, the dimensional tolerances allowed for the two types of assembled parts can be fully utilized, so that even in the cutting process, the fitting clearance between the annular fitting parts can be achieved without performing selective fitting. Can always be machined to be sufficiently small, and therefore, parts with high assembly precision can be manufactured at a low manufacturing cost.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an embodiment in which the fitting clearance control machining method for assembly parts according to the present invention is applied to the machining of the annular fitting parts of the right side part and the left side part of the automotive differential gear case in mass production. It is a block diagram which illustrates the processing apparatus used for implementation of an example, in the figure 1
Is a right-hand side part, 1a is its annular fitting part, 2 is a left-hand side part, and 2a is its annular fitting part. These parts 1 and 2 have the annular fitting parts 1a and 2a fitted together. They are assembled together to form a differential gear case for automobiles.

Reference numeral 31 in FIG. 1 denotes an annular fitting portion 1a of the right side component 1.
A normal inner diameter measuring device for measuring the inner diameter of the, a reference numeral 32 is a normal outer diameter measuring device for measuring the outer diameter of the annular fitting portion 2a of the left side component 2, and a reference numeral 33 is a calculation process including a normal microcomputer. Unit, 41 is a normal NC dedicated to processing the right side component 1.
Lathes, and 42 are normal NC lathes dedicated to machining the left side component 2, respectively, in which the arithmetic processing unit 33 is
Functionally, the first to seventh arithmetic processing circuits 34 to 39 are configured.

In such a processing apparatus, the fitting clearance control processing method of this embodiment is carried out as shown in FIG. That is, here, in advance, the dimensional tolerance R _K of the annular fitting portion 1a of the right-side component 1 and the center inner diameter R _H of the upper and lower limits of the regular dimension in consideration of it, and the annular fitting portion 2a of the left-side component 2 are set in advance.
Of the dimensional tolerance L _K and the center outer diameter L _H of the upper and lower limits of the normal dimension in consideration of it, and the fitting clearance between the annular fitting portion 1a of the right-side component 1 and the annular fitting portion 2a of the left-side component 2. The standard value z and the standard value z are input to the arithmetic processing unit 33, and
As shown in, the increase / decrease range within a predetermined amount from the clearance standard median z is defined as a correction unnecessary range, and
And the values A _R and A _L approximately equal to the predetermined amount P are set as the magnitude of the correction amount, and these values are input to the arithmetic processing unit 33.

First, in step 51, the NC lathe 41 dedicated to the right side component 1 is caused to machine the annular fitting portion 1a of the right side component 1 according to a predetermined machining program, and the NC lathe 42 dedicated to the left side component 2 is processed to the right side. The annular fitting portion 2a of the component 2 is machined according to a predetermined machining program, and then the step
At 52, the inner diameter measuring device 31 measures the processed inner diameter y _R of the annular fitting portion 1a of the right side component 1, and at the subsequent step 53, the first arithmetic processing circuit 34 measures the processed inner diameter y _R to the right side component. The difference x is obtained by subtracting the center diameter R _H of the dimensional tolerance of the annular fitting portion 1a of 1
Seeking _{R (x R = y R -R} H), this one, step 54
Then, the outer diameter measuring device 32 measures the outer diameter y _L of the annular fitting portion 2a of the left-side component 2 after machining, and in the next step 55, the second arithmetic processing circuit 34 measures the outer diameter y _L after the machining. Left part 2
The difference x _L by subtracting the median diameter L _H in the dimensional tolerances of the annular fitting portion 2a
(X _L = y _L −L _H ), and then, in step 56, by the third arithmetic processing circuit 36, the measured inner diameter y _R of the annular fitting portion 1 a and the measured inner diameter y _R of the annular fitting portion 2 a are processed. Outer diameter y
Calculate the fitting clearance y by calculating the difference of _L (y = y _R
-Y _L ), and in the following step 57, the third arithmetic processing circuit 36
Thus, a difference c between the fitting clearance y and the clearance standard median value z is obtained (c = yz).

Next, at step 58, the fourth arithmetic processing circuit 37 determines whether or not the difference between the obtained difference c and the predetermined amount P is positive (c-P> 0), and the difference c And a predetermined amount P
When the difference between and is positive (cp> 0), the clearance y after machining is out of the correction unnecessary range to the positive side (yz).
> P), the fifth arithmetic processing circuit is further processed in step 59.
38, the magnitudes of the differences x _R and x _L obtained earlier are compared. If x _R is larger than x _L (x _R > x _L ), the outer diameter y _L of the annular fitting portion 2a of the left-side component 2 is Since the inner diameter y _R of the annular fitting portion 1a of the right-side component 1 after machining is far from the center diameter of the dimensional tolerance, the seventh arithmetic processing circuit 40 determines the correction amount -A in step 60. _{After R} is given to the NC lathe 41 dedicated to the right side component 1, the process returns to step 51 to process the next components 1 and 2.

[0016] If the result x _R of the determination in step 59 is not greater than x _L is the fifth arithmetic processing circuit 38 in step 61, it is determined whether further x _R and the x _L are equal , X _R and x _L are not equal, that is, x _L is x
If it is larger than _R (x _L > x _R ), the outer diameter y _L of the annular fitting portion 2a of the left component 2 is larger than the inner diameter y _R of the annular fitting portion 1a of the right component 1 after processing. since it is greatly deviated from the median diameter, the seventh arithmetic processing circuit 40 in step 64, the left side part 2 dedicated NC lathe correction amount as + a _L
After feeding to 42, the process returns to step 51 to process the next parts 1 and 2.

Then, the result of the judgment in step 61 x
_{If R} and x _L are equal, the sixth arithmetic processing circuit 39 causes the difference w (w = R) between the dimensional tolerance R _K of the annular fitting portion 1a and the dimensional tolerance L _K of the annular fitting portion 2a by the sixth arithmetic processing circuit 39 in step 62. determine the _K -L _K), followed by the sixth arithmetic processing circuit 39 in step 63, further determines the sign of the difference w, in the case of w is positive (w> 0), the annular fitting portion on the left side part 2 since greater in dimensional tolerances R _K of the annular fitting portion 1a of the right part 1 than the dimensional tolerances L _K of 2a, the seventh arithmetic processing circuit 40 proceeds to step 60, the right amount of correction as -A _R NC lathe 41 dedicated to parts 1
, The next parts 1 and 2 are processed, and when w is not positive (w ≦ 0), the parts on the left side of the dimensional tolerance R _K of the annular fitting part 1a of the right part 1 are processed. Since the dimensional tolerance L _K of the second annular fitting portion 2a is greater than or equal to each other, the routine proceeds to step 64, and the seventh arithmetic processing circuit
By 40, the left part 2 only the correction amount as a + A _L NC
After feeding to the lathe 42, return to step 51 to move to the next parts 1 and 2.
To process.

On the other hand, if the result of determination in step 58 is that the difference between the difference c and the predetermined amount P is not positive, the routine proceeds to step 65, where the fourth arithmetic processing circuit 37 further determines the difference c obtained above. It is determined whether or not the sum with the predetermined amount P is negative (c + P <0). If negative, the clearance y after machining is out of the correction unnecessary range to the negative side (yz <-P). To step 66, the fifth arithmetic processing circuit 38 compares the magnitudes of the differences x _R and x _L previously obtained, and when x _R is larger than x _L (x _R > x _L ), the left side component 2 annular fitting 2a
Since the direction of the inner diameter y _R after processing of the annular fitting portion 1a of the right part 1 than the outer diameter y _L is far off from the center diameter of the dimensional tolerance, the seventh arithmetic processing circuit 40 in step 67, After the correction amount is given as -A _{R to} the NC lathe 41 dedicated to the right part 1, the process returns to step 51 and the next parts 1 and 2 are processed.

[0019] If the result x _R of the determination in step 66 is not greater than x _L is the fifth arithmetic processing circuit 38 in step 68, it is determined whether further x _R and the x _L are equal , X _R and x _L are not equal, that is, x _L is x
If it is larger than _R (x _L > x _R ), the outer diameter y _L of the annular fitting portion 2a of the left component 2 is larger than the inner diameter y _R of the annular fitting portion 1a of the right component 1 after processing. from that deviates significantly from the median diameter, the seventh arithmetic processing circuit 40 in step 71, the left side part 2 dedicated NC lathe correction amount as -A _L
After feeding to 42, the process returns to step 51 to process the next parts 1 and 2.

Then, the result x of the judgment in the above step 68
_{When R} is equal to x _L , the sixth arithmetic processing circuit 39 determines in step 69 the difference w (w = R) between the dimensional tolerance R _K of the annular fitting portion 1a and the dimensional tolerance L _K of the annular fitting portion 2a. _K− L _K ), and in step 70, the sixth arithmetic processing circuit 39 further determines whether the difference w is positive or negative. If w is positive (w> 0), the annular fitting portion of the left component 2 is determined. Since the dimensional tolerance R _K of the annular fitting portion 1a of the right-side component 1 is larger than the dimensional tolerance L _{K of} 2a, the routine proceeds to step 67, where the seventh arithmetic processing circuit 40 sets the correction amount to + A _R and the right-side component. 1 dedicated NC lathe 41
, The next parts 1 and 2 are processed, and when w is not positive (w ≦ 0), the parts on the left side of the dimensional tolerance R _K of the annular fitting part 1a of the right part 1 are processed. Since the dimensional tolerance L _K of the second annular fitting portion 2a is larger than or equal to each other, the routine proceeds to step 71, where the seventh arithmetic processing circuit.
By 40, the correction amount left part 2 only as -A _L NC
After feeding to the lathe 42, return to step 51 to move to the next parts 1 and 2.
To process.

Further, as a result of the judgment in step 65,
If the sum of the difference c and the predetermined amount P is not negative, the clearance y after machining is within the correction-unnecessary range (−P ≦ yz− + P). , N for the right side component 1 with the correction amount set to 0 (no correction)
After the C-lathe 41 and the NC lathe 42 dedicated to the left-side component 2 are respectively provided, the process returns to step 51 to process the next components 1 and 2.

As described above, according to the method of this embodiment, the calculated diameters y _R and y _L after machining and the tolerance center diameters R _H and L are obtained.
Compare the difference x _R and x _L with _H, and determine the diameter to be machined for the part with the larger difference ± A _R or ± A
By correcting _L only, it is possible to fully utilize the dimensional tolerances allowed for the two types of assembled parts, the right-side part 1 and the left-side part 2, so selective mating is possible even when cutting with NC lathes 41 and 42. It is possible to perform processing so that the fitting clearance y between the annular fitting portions is always sufficiently small without performing the above operation.
2 can be produced.

Further, according to the method of this embodiment, when the differences x _R and x _L are equal to each other, the dimensional tolerance R _K of the annular fitting portion 1a and the dimensional tolerance L _K of the annular fitting portion 2a are compared. hand,
Since the diameter to be machined for the component having the larger dimensional tolerance is corrected, the dimensional tolerances allowed for the two types of assembled components can be further utilized.

Although the present invention has been described above with reference to the illustrated example, the present invention is not limited to the above example. For example, in the above embodiment, the absolute value of the correction amount is set to the constant value A, A _L. A value c / a obtained by multiplying the difference c between the clearance y and the clearance standard median value z by 1 / a (a is an arbitrary number above) may be used as the absolute value of the correction amount.

[0025]

As described above, according to the fitting clearance control machining method of the present invention, the dimensional tolerances allowed for the two types of assembled parts can be fully utilized, so that selective mating is not performed even during cutting. Can be machined so that the fitting clearance between the annular fitting parts is always sufficiently small.
Therefore, it is possible to manufacture a component having high assembly accuracy at a low manufacturing cost.

[Brief description of drawings]

FIG. 1 is used to carry out an embodiment of an embodiment in which the fitting clearance control machining method for an assembled component of the present invention is applied to the machining of an annular mating portion of a right component and a left component of a differential gear case for automobiles. It is a block diagram which illustrates a processing apparatus.

FIG. 2 is a flowchart showing a procedure of a fitting clearance control processing method of the above embodiment.

FIG. 3 is an explanatory diagram showing a median clearance standard value and a correction unnecessary range setting amount in the fitting clearance control processing method of the above embodiment.

FIG. 4 is a cross-sectional view showing a right side component and a left side component that constitute a differential gear case for an automobile, as examples of two types of assembly components in which annular fitting portions are fitted to each other and assembled together.

5 (a) and 5 (b) are flowcharts showing a conventional annular fitting portion size control processing method, respectively.

[Explanation of symbols]

1 Right side component 1a Annular fitting part 2 Left side component 2a Annular fitting part 31 Inner diameter measuring instrument for annular fitting part 1a 32 Outer diameter measuring instrument for annular fitting part 2a 33 Arithmetic processing unit 34 1st arithmetic processing circuit 35 2nd Arithmetic processing circuit 36 Third arithmetic processing circuit 37 Fourth arithmetic processing circuit 38 Fifth arithmetic processing circuit 39 Sixth arithmetic processing circuit 40 Seventh arithmetic processing circuit 41 NC lathe dedicated to machining right side component 1 NC dedicated to machining left side component 2 Lathe R _K Dimensional tolerance of annular fitting part 1a of right part 1 R _H Regular inner and outer diameters of upper and lower limits of annular fitting part 1 L _K Dimensional tolerance of annular fitting part 2a of left part 2 L _H Annular fitting Outer diameter of the upper and lower limits of the normal dimension of the part 2a z Center value of the fitting clearance between the annular fitting part 1a and the annular fitting part 2a P Uncorrected range setting amount A _R NC Lathe 41 correction amount absolute value A _L after processing the outer diameter of the NC lathe 42 of the correction amount of the absolute value y after processing the inside diameter of the _R annular fitting portion 1a y _L annular engaging portion 2a Minus the _R post-machining the inner diameter y _R tolerances median diameter R _H (x
_{R = y R -R H) x} L after processing outer diameter y _L minus a tolerance median diameter L _H from (x
_L = y _L -L _H) y fitting clearance (y = y _R -y _L) difference between c fitting clearance y and clearance specifications median z (c = y-z) w tolerances R _K and dimensional tolerance Difference from L _K (w = R _K −L
_K )

Claims (1)

[Claims] 1. When mass-producing two types of assembly parts (1, 2) to be assembled together, a cutting process of annular fitting parts (1a, 2a) of the assembly parts to be fitted to each other is performed. When each is performed, the diameter (y _R , y _L ) of the annular fitting portion of the assembly part that has been cut previously is measured, and the measured diameter after machining and the annular fitting portion are measured. , The difference (x _R , x _L ) from the center diameter ( _RH , L _H ) of the upper and lower limits of the normal dimension taking into account the tolerance, and the fitting clearance between the measured diameters ( y), and further, a difference (c) between the calculated fitting clearance and the center value (z) of the clearance standard is calculated, and the difference between the calculated fitting clearance and the center value of the clearance standard is a predetermined value. When it exceeds (P), the difference between the obtained diameter after processing and the center diameter of the tolerance is large. A fitting clearance control machining method for an assembled component, characterized in that, for one type of component, the machining diameter is corrected by a predetermined amount (A _R , A _L ) and the subsequent component is machined.