JP6045062B2 - Dimension management method for two-piece oil ring wire and dimensional management device for two-piece oil ring wire - Google Patents

Description

  The present invention relates to a dimension management method and a dimension management apparatus for a two-piece type oil ring wire used for manufacturing a two-piece type oil ring including an oil ring body and a coil expander used for an internal combustion engine.

  Conventionally, an oil ring mounted on a piston of an internal combustion engine has an oil ring body composed of a pair of upper and lower rails that slide on the inner wall surface of the cylinder and a web that connects these rails, and the oil ring body is disposed radially outward. There is a two-piece oil ring consisting of a coil expander that presses in the opposite direction. The size and shape of this two-piece type oil ring are carefully controlled so that the tension of the coil expander is uniformly transmitted in the circumferential direction of the upper and lower rail portions of the oil ring body. Usually, the dimensional shape of the oil ring main body constituting the two-piece type oil ring is confirmed in the state of the wire before being processed into a ring shape. This is because if the dimension measurement is performed after processing the wire into the oil ring body, the complicated shape becomes more complicated, making it difficult to measure with high accuracy and increasing the time spent on dimension measurement. is there. If the variation in dimensions of the oil ring main body is not performed in the state of the wire, when a defective product with a dimension and shape is detected after being processed into the oil ring main body, the time spent for the processing is wasted and the manufacturing cost is reduced. Will increase. As described above, with respect to the oil ring main body, the function required as the oil ring is ensured while reducing the product cost by performing the dimension measurement in the state of the wire and managing the product quality.

  FIG. 1 is a perspective view showing a main part of an oil ring body provided with an oil return groove. FIG. 3 is a schematic cross-sectional view showing a dimension measurement location in a conventional two-piece type oil ring wire. In FIG. 1, a two-piece oil ring 1 includes an oil ring main body 2 and a coil expander 6 (a virtual cross section ( It is shown that it is composed of an alternate long and short dash line). As shown in these drawings, the oil is efficiently discharged into the coil expander accommodating recess 2b on the inner peripheral side in which the coil expander 6 is attached to the oil ring body 2 of the two-piece type oil ring 1. There is a form in which a groove portion 2a is formed.

  As shown in FIGS. 1 and 3, the two-piece type oil ring 1 in which the oil return groove 2 a is provided in the oil ring main body 2 is a dimension management part for assuring a function required as an oil ring. Conventionally, the locations shown in A, B, and C shown in FIG. 3 are set, and the dimensions are measured in the state of the wire. That is, the dimension management locations indicated by A, B, and C in FIG. 3 are locations that are important in terms of product quality and product function, and the 2-piece type oil ring 1 The functions assumed at the time of design can be fully exhibited. By the way, in the past, when measuring the dimensions A, B, C shown in FIG. 3 of the two-piece type oil ring wire 2 ′, it is difficult to perform contact measurement using a caliper, a micrometer, etc. The measurement function was added to the observation function for the dimensions of the portions A, B, and C on the cut surface (corresponding to the cross section in the oil ring axial direction of the oil ring body) of the wire piece cut by cutting perpendicularly to the axis It was measured using a measuring microscope or the like.

  However, the measuring microscope described above is (1) the shape of the portion shown in FIGS. 3A, 3B and 3C in the two-piece type oil ring wire 2 ′ is complicated, and the measurement operator's Measurement variation is likely to occur due to skill level, etc. (2) When measuring the dimensional shape of the two-piece oil ring wire 2 ′ that is the object to be measured, the two-piece oil ring wire 2 ′ must be cut. It is difficult to measure dimensions quickly, (3) There are restrictions on the installation location because it requires an AC power source, (4) It is expensive, (5) It is large and difficult to carry, etc. Have For this reason, conventionally, in determining the variation in the dimensional shape of the two-piece type oil ring wire 2 ′, inconveniences such as being unable to measure quickly and accurately have occurred.

  In view of the above, the present invention quickly and accurately measures the variation in the dimensional shape of the two-piece oil ring wire 2 ', and the shape of the two-piece oil ring wire 2' is outside the dimensional tolerance. 2-piece oil ring 1 for obtaining a two-piece type oil ring 1 which is excellent in functions such as sealing and oil control required for an oil ring for internal combustion engines by properly eliminating oil ring tension variation An object of the present invention is to provide a dimension management method for a wire rod for a type oil ring and a size management device for a wire piece for a two-piece type oil ring.

Therefore, as a result of earnest research, the present inventors have determined a predetermined index as an alternative index for determining the presence or absence of dimensional variation caused by any one of the dimension measurement positions shown in A, B, and C of FIG. The above-mentioned problems have been solved by adopting a method of measuring and managing the dimensions of a predetermined location in a state where the dimension management jig is combined with the two-piece type oil ring wire.

Dimension management method for wire piece for two-piece type oil ring according to the present invention: The dimension management method for wire piece for two-piece type oil ring according to the present invention comprises an upper and lower rail part and a web part connecting these rail parts. Dimension management method for two-piece type oil ring wire rod having a substantially I-shaped cross section in which a plurality of oil return holes are provided in the web portion, and an oil return groove portion communicating with the oil return hole is provided in a coil expander accommodating recess in the inner circumference of the web portion The cylindrical portion in a dimension control jig having a cylindrical portion or a spherical portion having an outer diameter equivalent to the outer diameter of the coil expander that presses the upper and lower rail portions outward in the radial direction of the oil ring. In a state where the cylindrical surface or spherical surface of the spherical shape portion is brought into contact with the vicinity of the oil return groove portion of the coil expander housing concave portion surface of the wire piece for the two-piece type oil ring, The length in the oil ring radial direction of the wire piece for the two-piece type oil ring including the cylindrical part or the spherical part of the dimension management jig is measured, and this measured value is measured in the wire piece for the two-piece type oil ring. The oil ring radial length from the oil ring outer peripheral end of the upper and lower rails to the bottom surface of the oil return groove, the oil ring radial depth of the oil return groove, and the oil ring axial direction of the oil return groove It is used as an alternative index for determining the presence or absence of dimensional variation due to any one of the widths .

  Further, in the dimension management method for a two-piece type oil ring wire according to the present invention, the dimension management jig is a pin gauge composed only of a cylindrical portion having an outer diameter tolerance of ± 0.005 μm, or an outer diameter tolerance of ± 0.005 μm. It is preferable that the ball gauge has a spherical portion.

Dimension management device for two-piece type oil ring wire: The two-piece type oil ring wire dimensional management device according to the present invention determines the presence or absence of dimensional variation by the above-described two-piece type oil ring wire dimensional management method. A two-piece oil ring wire size management device for use as an alternative indicator, wherein the two-piece oil ring wire size management device sandwiches an object to be measured between a pair of opposing measurement surfaces. A mechanism for measuring a dimension based on a distance between the measurement surfaces of the measurement surface, and the measurement mechanism is configured to fix a columnar shape portion or a spherical shape portion included in the dimension management jig on one measurement surface. Features.

According to the dimension management method for a two-piece oil ring wire and the dimension management device for a two-piece oil ring wire according to the present invention, in a state where a predetermined dimension management jig is combined with the two-piece oil ring wire. The measured value at the predetermined location can be used as an alternative index for determining the presence or absence of variation in the size of the location due to any of the size measurement locations shown in A, B, and C of FIG. Accordingly, by adopting the two-piece type oil ring wire size management method and the two-piece type oil ring wire size management device according to the present invention, it is possible to suppress variations in the dimensions of the two-piece type oil ring wire. As a result, the dimensional accuracy of the two-piece type oil ring wire can be improved.

It is the principal part perspective view which showed one form of the oil ring main body provided with the oil return groove | channel. It is a schematic sectional drawing for demonstrating the dimension management method of the wire piece for 2 piece type oil rings which concerns on this invention, and the dimension management apparatus of the wire piece for 2 piece type oil rings. It is the schematic sectional drawing which showed the dimension measurement location in the conventional 2 piece type oil ring wire. It is the schematic sectional drawing which showed the dimension measurement location in the wire for two-piece type oil rings of the form different from FIG.

  A preferred embodiment of a dimension management method for a two-piece type oil ring wire and a dimension management device for a two-piece type oil ring wire according to the present invention will be described in more detail with reference to the drawings. .

  FIG. 2 is a schematic cross-sectional view for explaining a dimension management method for a two-piece type oil ring wire and a dimension management device for a two-piece type oil ring wire according to the present invention.

Dimension management method for two-piece type oil ring wire according to the present invention: The dimensional management method for the two-piece type oil ring wire 2 'according to the present invention is a web portion connecting upper and lower rail portions 3 and 5 and these rail portions. The web portion 4 has a plurality of oil return holes 4a and a coil expander accommodating recess 2b on the inner periphery of the web portion, and an oil return groove portion 2a communicating with the oil return hole 4a. This is a dimension management method for the two-piece type oil ring wire 2 '. As shown in FIG. 1, the two-piece type oil ring 1 has a configuration in which an oil return groove 2a communicating with an oil return hole 4a is formed in a coil expander accommodating recess 2b on the inner peripheral side. The oil return groove 2a is formed in the two-piece type oil ring 1, so that excess oil scraped off from the cylinder inner wall surface (not shown) by the upper rail portion 3 and the lower rail portion 5 can be quickly oiled. It is possible to discharge through the inner periphery of the ring.

Moreover, the dimension management method of the wire piece for 2 piece type oil rings which concerns on this invention is the outer diameter dimension equivalent to the outer diameter of the coil expander 6 which presses the said upper-and-lower rail parts 3 and 5 to an oil ring radial direction outward. The cylindrical surface of the cylindrical part or the spherical surface of the spherical part in the dimension management jig 10 having a cylindrical part or a spherical part is formed on the surface of the coil expander accommodating recess 2b of the wire piece 2 ′ for the two-piece type oil ring. A two-piece type oil ring wire 2 ′ including a cylindrical part or a spherical part of the dimension management jig 10 in a state where it is in contact with the vicinity of the oil return groove 2a (two points X shown in FIG. 2). Measure the length of the oil ring in the radial direction. And the dimension control method of 2 piece type | mold oil ring wire 2 'which concerns on this invention uses this measured value for the oil ring outer peripheral side of the said upper and lower rail parts 3 and 5 in the said 2 piece type oil ring wire 2'. Length in the oil ring radial direction from the tip to the bottom surface of the oil return groove 2a (location A shown in FIG. 3), depth in the oil ring radial direction of the oil return groove 2a (location B shown in FIG. 3) , and it is characterized in that used as an alternative index for determining whether the variation in dimensions due to either the oil return groove 2a of the oil ring axial width (locations C shown in FIG. 3).

As shown in FIG. 2, the dimension management method for the two-piece type oil ring wire according to the present invention is a dimension management jig 10 having a cylindrical or spherical part having an outer diameter equivalent to that of the coil expander 6. , The cylindrical surface of the cylindrical portion or the spherical surface of the spherical portion is formed in the vicinity of the oil return groove portion 2a on the surface of the coil expander accommodating recess 2b of the two-piece type oil ring wire 2 ′ (shown in FIG. 2). It can be stably mounted in contact with two X points). As a result, the dimension management method for the two-piece type oil ring wire according to the present invention is the oil ring diameter of the two-piece type oil ring wire 2 ′ including the cylindrical part or the spherical part of the dimension management jig 10. By measuring the length in the direction, it is possible to determine whether or not there is a dimensional variation in a location caused by any of A, B, and C shown in FIG.

Here, in the dimension management method for the two-piece type oil ring wire according to the present invention, the oil ring radial direction of the two-piece type oil ring wire 2 ′ including the cylindrical part or the spherical part of the dimension management jig 10. Can be used as an alternative index for determining whether or not there is a variation in the size of the part due to any of A, B, and C shown in FIG. 3 in the wire piece 2 ′ for the two-piece type oil ring. Let me give you a specific reason.

As described above, the size management method of a conventional two-piece type oil ring for wire is in determining whether a variation in the dimensions of the two-piece type oil ring for wire 2 ', A shown in FIG. 3, B, the C Measure the size of the location due to one of them. On the other hand, the dimension management method for the two-piece type oil ring wire according to the present invention is the same as the coil expander 6 in determining whether or not there is a variation in the dimension of the two-piece type oil ring wire 2 ′. In the dimension management jig 10 having a cylindrical portion or a spherical shape portion having a diameter dimension (location D shown in FIG. 2), the cylindrical surface of the cylindrical shape portion or the spherical surface of the spherical shape portion is replaced with the two-piece type oil ring. 2 is measured in a state where it is in contact with the vicinity of the oil return groove 2a (two points X shown in FIG. 2) on the surface of the coil expander housing recess 2b of the wire 2 '. Here, in the 2-piece type oil ring wire 2 ′, the length in the oil ring radial direction (A + B) shown in FIG. 3 is equal to the length in the oil ring radial direction shown in FIG. 2 (E− (D / 2 + D × cos θ / 2) The length in the oil ring axial direction (C) shown in FIG. 3 substantially corresponds to the length in the oil ring axial direction (D × sin θ) shown in FIG. Therefore, the dimension at the position D shown in FIG. 2 is always constant by using the dimension management jig 10, and the center of the dimension management jig 10 shown in FIG. The angle θ formed by the straight line connecting the contact point (point X) with the surface of the panda housing recess 2b and the straight line parallel to the oil ring radial direction also affects the dimension of the portion E shown in FIG. This length can be used as an alternative index for determining the presence or absence of variation in the size of the location due to any of A, B, and C shown in FIG.

As described above, the dimension management method for the two-piece type oil ring wire according to the present invention is based on the conventional method of determining whether or not there is a variation in the dimension of the part due to any one of A, B, and C shown in FIG. Thus, it is only necessary to perform dimension measurement for the part E shown in FIG. 2 without performing dimension measurement for all of these parts A, B, and C, so that the measurement accuracy is improved and the measurement time is greatly increased as compared with the prior art. Can be shortened. In addition, since the measurement point E shown in FIG. 2 in the two-piece type oil ring wire 2 ′ can be easily measured using a general purpose caliper or the like, it is restricted to the place where the dimension measurement is performed as in the past. I will not receive it.

FIG. 4 is a schematic cross-sectional view showing a dimension measurement place in a two-piece type oil ring wire having a different form from that in FIG. As shown in FIG. 4, the location C shown in FIG. 3 is set with reference to the tangent of the R portion (refer to “R1” and “R2” in the figure) at the corner of the oil return groove 2a. Thus, as the cross-sectional shape of the two-piece type oil ring wire 2 ′ becomes more complicated, the conventional two-piece type oil ring wire dimensional management method uses A, B, It becomes impossible to quickly and accurately measure the dimensional variation of the location caused by any one of C. However, according to the dimension control method for a two-piece type oil ring wire according to the present invention, even if the two-piece type oil ring wire 2 'has a cross-sectional shape as shown in FIG. It is possible to suppress the variation in the size of the part due to any one of A, B, and C of the wire 2 ′, and as a result, it is possible to improve the dimensional accuracy of the wire 2 ′ for the two-piece type oil ring. . Therefore, according to the dimension management method of the wire for two-piece type oil ring according to the present invention, the measurement variation due to the skill level of the measurer is reduced, and the quality stable oil ring body 2 is manufactured at low cost. I can do it.

  In the dimension management method for a two-piece type oil ring wire according to the present invention, the dimension management jig 10 is a pin gauge consisting only of a cylindrical portion having an outer diameter tolerance of ± 0.005 μm, or an outer diameter tolerance of ± 0.005 μm. It is preferable that the ball gauge has a spherical portion.

  The dimension management method for the two-piece type oil ring wire according to the present invention includes a pin gauge consisting only of a cylindrical portion having an outer diameter tolerance of ± 0.005 μm or a ball having an outer diameter tolerance of ± 0.005 μm as the dimension management jig 10. By using a high-precision standard gauge of a ball gauge with a shape part, it is possible to further suppress the dimensional variation of the two-piece oil ring wire 2 ', and as a result, the two-piece oil ring wire 2'. The dimensional accuracy can be further improved. The reason is shown below.

First, the dimensional variation due to the dimensional management method of the conventional two-piece type oil ring wire is based on the dimensional tolerances a, b, and c shown in FIG. a + b ”, and the variation in the oil ring axial direction is“ c ”. In FIG. 3, a straight line connecting the oil ring outer peripheral end of the upper rail portion 3 and the oil ring outer peripheral end of the lower rail portion 5 is defined as an X axis, and the upper surface of the upper rail portion 3 on the X axis and the lower rail The variation in the position of the X point when a straight line passing through the origin and perpendicular to the X axis is set as the Y axis is expressed as “√ ((a + b) ² + (c / 2). ² ) ". On the other hand, the dimensional variation due to the dimensional management method of the two-piece type oil ring wire according to the present invention is the variation in the oil ring radial direction from the dimensional tolerances d and e of D and E shown in FIG. Thus, the variation in the oil ring axial direction is “d × sin θ”. In FIG. 2, a straight line connecting the oil ring outer peripheral end of the upper rail portion 3 and the oil ring outer peripheral end of the lower rail portion 5 is defined as an X axis, and the upper surface of the upper rail portion 3 on the X axis and the lower rail The variation in the position of the X point when the intermediate point with the lower surface of the part 5 is set as the origin and the straight line passing through the origin and perpendicular to the X axis is set as the Y axis is “√ ((d + e) ² + ((d / 2) × sin θ) ² ) ”.

  Based on the above, the following shows the dimensional measurement of the two-piece oil ring wire 2 'by the conventional two-piece oil ring wire dimension management method and the dimension management of the two-piece oil ring wire according to the present invention. Comparison with the dimensional measurement value of the two-piece type oil ring wire 2 ′ by the method is performed. In making this comparison, A ± a in FIG. 3 is 1.21 ± 0.02 (mm), B ± b is 0.13 ± 0.03 (mm), and C ±. A two-piece oil ring wire 2 ′ designed so that c is 0.70 ± 0.05 (mm) was used. First, in the case of adopting the conventional dimension control method for the two-piece type oil ring wire, the variation in the position of the point X shown in FIG. 3 is about 0.056 as a result of calculation based on the calculation formula shown above. (Mm). On the other hand, in the dimension management method for the two-piece type oil ring wire according to the present invention, the outer diameter of the coil expander 6 is provided in the coil expander housing recess 2b of the two-piece type oil ring wire 2 ′ having the above-described dimensions. 2, when the dimension management jig 10 having D ± d of 1.50 ± 0.005 (mm) is attached, the center of the dimension management jig 10 in FIG. Since the angle θ formed by the straight line connecting the contact point (X point) with the surface of the coil expander housing recess 2b and the straight line corresponding to the Y-axis is about 30 degrees, the dimension management jig 10 is included. In FIG. 2, E ± e is set to 2.749 ± 0.023 (mm) by design. As a result, in the case of adopting the dimension management method for the two-piece type oil ring wire according to the present invention, the position variation of the point X shown in FIG. 2 is calculated based on the calculation formula shown above. 0.028 (mm). Therefore, according to the dimension management method for the two-piece type oil ring wire according to the present invention, the dimension of the two-piece type oil ring wire 2 'is more accurate than the conventional two-piece type oil ring wire dimension management method. It is possible to determine the presence or absence of variation.

  The two-piece type oil ring 1 can reduce the variation in tension by suppressing the dimensional variation of the oil ring body 2. This is because the tension of the two-piece oil ring 1 changes in proportion to the amount of contraction (deflection allowance) of the coil expander 6 attached to the oil ring body 2. By the way, from the results shown above, the two-piece oil ring wire according to the present invention when the tension variation of the oil ring when adopting the conventional dimension control method of the two-piece oil ring wire is taken as 1. When the dimensional management method is adopted, the oil ring tension variation is 0.4. Thus, by adopting the dimension management method for a two-piece type oil ring wire according to the present invention, it is possible to provide a high-quality two-piece type oil ring 1 with less tension variation than the conventional one.

Dimension management device for two-piece oil ring wire according to the present invention: The dimension management device for a two-piece oil ring wire 2 'according to the present invention is dimensioned by the above-described dimension management method for a two-piece oil ring wire. It is used as an alternative index for determining the presence or absence of variations in Further, the dimension management device for the two-piece type oil ring wire includes a mechanism for measuring a dimension based on a distance between the measurement surfaces when the target measurement object is sandwiched between a pair of opposing measurement surfaces. The measurement mechanism is characterized in that a cylindrical part or a spherical part provided in the dimension management jig is fixed on one measurement surface.

  The dimension management device for a two-piece type oil ring wire according to the present invention includes a mechanism for measuring a dimension based on a distance between the measurement surfaces when the target measurement object is sandwiched between a pair of measurement surfaces facing each other. 2 can be accurately measured. Further, in the dimension management device for a two-piece type oil ring wire according to the present invention, the measurement mechanism fixes a cylindrical part or a spherical part provided in the dimension management jig on one measurement surface. 2 can be quickly measured for the dimension E.

  For reference, the dimension management device for a two-piece oil ring wire according to the present invention can suitably use a micrometer as a measuring mechanism. For example, in the dimension management device for a two-piece type oil ring wire according to the present invention, the measurement mechanism has a cylindrical part or a spherical part provided in the dimension management jig on the measurement surface on the anvil side of the micrometer. By fixing, it is possible to suppress measurement variations caused by the skill level of the measurer and obtain the best measurement accuracy in a short time. As described above, the two-piece type oil ring wire size management device according to the present invention can use a general-purpose measuring instrument as it is, and can suppress an increase in manufacturing cost and product cost.

  As described above, according to the dimension management method for the two-piece type oil ring wire according to the present invention and the dimension management apparatus for the two-piece type oil ring wire according to the present invention, the dimensions of the two-piece type oil ring wire As a result, the dimensional accuracy of the two-piece type oil ring wire 2 'can be improved. Therefore, the shape of the two-piece type oil ring wire 2 'can be obtained by employing the two-piece type oil ring wire size management method according to the present invention and the two-piece type oil ring wire size management device according to the present invention. Therefore, it is possible to appropriately eliminate those that are outside the dimensional tolerances, so that variations in the tension of the oil ring are suppressed, and the functions such as sealing and oil control required for the oil ring for internal combustion engines are excellent. A two-piece oil ring 1 can be obtained.

  The dimension management method for a two-piece type oil ring wire according to the present invention and the dimension management device for a two-piece type oil ring wire according to the present invention can be used to manage the dimension of a two-piece type oil ring wire, such as calipers and micrometers. Since a general-purpose measuring instrument can be used, it is possible to control the dimensions of the oil ring main body at a low cost and reduce the product cost of the two-piece type oil ring. In addition, according to the dimension management method for a two-piece type oil ring wire and the dimension management device for a two-piece type oil ring wire according to the present invention, the inner periphery side coil expander-accommodating recess has not only an R-shaped cross section. It can also be suitably used for a V-shaped two-piece oil ring wire. Therefore, the dimension management method for the two-piece type oil ring wire according to the present invention and the dimension management device for the two-piece type oil ring wire according to the present invention include, for example, a seal such as an O-ring so that liquid or gas does not leak to the outside. It can also be diverted as a means for judging variations in the size and shape of the part where the seal member is mounted in a machine or apparatus in which the member is used.

DESCRIPTION OF SYMBOLS 1 2 piece type oil ring 2 Oil ring main body 2 '2 piece type oil ring wire 2a Oil return groove part 3 Upper rail part 4 Web part 4a Oil return hole 5 Lower rail part 6 Coil expander 10 Dimension management jig R1 Oil return R part at the corner of the groove (upper rail side)
R2 R part at the corner of the oil return groove (lower rail part side)
D Dimension management jig diameter X Contact part between dimension management jig and oil ring body

Claims (3)

It consists of upper and lower rail parts and a web part connecting these rail parts, and a plurality of oil return holes are provided in the web part, and an oil return groove part communicating with the oil return hole is provided in a coil expander housing recess in the inner periphery of the web part. A method for managing dimensions of a two-piece oil ring wire having a substantially I-shaped cross section,
The cylindrical surface of the cylindrical part in the dimension control jig provided with a cylindrical part or a spherical part having an outer diameter equal to the outer diameter of the coil expander that presses the upper and lower rail parts outward in the oil ring radial direction or In a state in which the spherical surface of the spherical portion is brought into contact with the vicinity of the oil return groove portion of the concave portion of the coil expander housing of the wire piece for the two-piece type oil ring, the cylindrical portion or the spherical portion of the dimension management jig is included. Measure the length of the oil ring radial direction of the two-piece oil ring wire,
This measured value is obtained by measuring the length in the oil ring radial direction from the oil ring outer peripheral end of the upper and lower rail portions to the bottom surface of the oil return groove portion, and the oil ring diameter of the oil return groove portion in the two-piece oil ring wire. direction of depth, and dimensional control of the two-piece type oil ring for wire, which comprises using as an alternative index for determining whether the variation in the resulting dimensions in any one of the oil return oil ring axial width of the groove Method.   2. The two-piece according to claim 1, wherein the dimension management jig is a pin gauge composed of only a cylindrical portion having an outer diameter tolerance of ± 0.005 μm, or a ball gauge having a spherical portion having an outer diameter tolerance of ± 0.005 μm. Dimension control method for mold oil ring wire. A two-piece type oil ring wire size management device for use as an alternative index for determining the presence or absence of dimensional variation by the two-piece type oil ring wire size management method according to claim 1 or 2. ,
The dimension control device for the two-piece type oil ring wire includes a mechanism for measuring a dimension based on a distance between the measurement surfaces when the target measurement object is sandwiched between a pair of opposing measurement surfaces. A two-piece type oil ring wire dimension management device, wherein a mechanism for fixing a cylindrical part or a spherical part provided in the dimension management jig on one measurement surface is fixed.

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