JP2023092986A - Method for measuring symmetry of width across flats - Google Patents

Abstract

To provide a method pertaining to a workpiece that includes a width across flats part and includes a cylindrical part whose diameter is constant along the axial direction, and helping to easily measure the symmetry of the width across flats part to the cylindrical part.SOLUTION: The present invention is a method regarding a workpiece that includes a width across flats part 2 where one flat is a first plane 21 and the other flat is a second plane 22 and includes a cylindrical part 1 whose diameter is constant along an axis Z, and measuring the symmetry of the width across flats part 2 to the cylindrical part 1. When the planes parallel to the first plane 21 and second plane 22 are generally named reference planes 3, the distance between the first plane 21 and one of the reference planes 3 that are in contact with the outer surface of the cylindrical part 1 on the side close to the second plane 22 is defined as a first distance E, and the distance between the second plane 22 and one of the reference planes 3 that are in contact with the outer surface of the cylindrical part 1 on the side close to the first plane 21 is defined as a second distance F, the method involves measuring the first distance E and the second distance F, then finding the absolute value of the difference between the two.SELECTED DRAWING: Figure 5

Description

The present invention relates to a method for measuring the degree of symmetry across two surfaces.

Conventionally, for example, the width across flats shape for clamping on the cylindrical body of a work has a standard of "degree of symmetry with respect to the cylindrical part".

By the way, there are few known techniques for measuring the width across flats. However, there is no known technique for measuring the "degree of symmetry" of the width across flats shape.

JP 2009-145052 A

The width across flats shape as described above is determined according to the shape of the device at the work mounting position, such as the outer diameter of the cylindrical portion, the longitudinal dimension, the thickness of the width across flats, and the longitudinal position with respect to the cylindrical portion. There are huge variations in dimensions. For this reason, in order to measure the "degree of symmetry with respect to the cylindrical portion", it was necessary to prepare a special instrument for each dimensional variation, and an increase in manpower and man-hours was unavoidable.

The present invention has been created in view of these problems, and its object is to provide a work that includes a width across flats portion and a cylindrical portion whose diameter is constant along the axis. To provide a method for simply measuring a degree.

A first aspect of the present invention comprises a width across flat portion (2) having one side as the first side (21) and the other side as the second side (22), the diameter along the axis (Z) A method for measuring the degree of symmetry of the width across flats part of a work containing a cylindrical part (1) that is constant at a constant , the distance between the first surface and one of the reference surfaces in contact with the outer surface of the cylindrical portion on the side closer to the second surface is defined as a first distance (E), and the distance between the second surface and the cylindrical portion on the side closer to the first surface is When the distance to one of the reference surfaces in contact with the outer surface is defined as the second distance (F), the first distance and the second distance are measured, and the absolute value of the difference between the two values is obtained. is.

A second aspect of the present invention comprises a width across flat portion (2) having one side as the first side (21) and the other side as the second side (22), the diameter along the axis (Z) A method for measuring the degree of symmetry of the width across flats part of a work containing a cylindrical part (1) with a constant width with respect to the cylindrical part, wherein the surface parallel to the first and second surfaces and containing the axis of the cylindrical part is the cylindrical part A center plane (100), a distance A (A) between the first plane and the center plane of the cylindrical section, a distance B (B) between the second plane and the center plane of the cylindrical section, and the same When the vertical direction (G) is the vertical direction (G) with respect to the groove (4) formed so that the two planes of width intersect each other at the same angle, the first surface or the second surface is vertical. Place the workpiece in the groove so that it is parallel to the direction and the cylindrical part of the workpiece abuts along the axis, measure the distance A and distance B, and obtain the absolute value of the difference between the two values. It is a symmetry measurement method.

This makes it possible to easily measure the degree of symmetry of the width across flats portion of the workpiece with respect to the cylindrical portion.

FIG. 4 is a side view of a state in which the width across flats portion of the workpiece is clamped; FIG. 2 is a plan view of FIG. 1; FIG. 2 is a front view of FIG. 1; FIG. 4 is a schematic diagram for explaining a method for measuring the degree of symmetry across two surfaces according to the first embodiment; FIG. 1 is a schematic diagram 1 for explaining a method for measuring the degree of symmetry across two surfaces according to a second embodiment; FIG. 2 is a schematic diagram 2 for explaining the width across flats symmetry measuring method of the second embodiment;

[applicable target]
A plurality of embodiments of the present invention will be described below with reference to the drawings. In the following embodiments, the workpiece W is assumed to be an engine injector. The application target of the present invention is shown in FIGS. 1-3. A clamping width across flats portion is provided on a cylindrical body of an injector component for an engine centered on the axis Z, and an arm A gripping the width across flats portion 2 as shown in FIGS. installation to the

[Symmetry of width across flats]
Here, when the injector is inserted into the mounting hole with the width across flats as the reference, even if the standards for coaxiality and straightness of the cylindrical portion are met, if the symmetry of the width across flats is not as shown in the drawing, the The tip may come into contact with the inner wall of the hole and be damaged. For this reason, the drawing indicates that the degree of symmetry with respect to the cylindrical outer diameter of the body should be, for example, 0.1 mm. The degree of symmetry of the width across flats is defined as "the amount of deviation from the symmetrical position of a feature that should be symmetrical with respect to the datum axis straight line or the datum center plane". Applying this to the drawing instructions, the actual "central plane of the width across flats" of the work W is from the ideal "datum center plane" (a plane parallel to the width across flats 2 and including the axis Z of the work W). It should be within the range of ±0.05 mm.

(First embodiment)
First, the second aspect (first embodiment) of the present invention, in which the degree of symmetry is obtained by measuring the distance between the datum center plane of the workpiece W and each surface having a width across flats from the datum center plane, will be described.

FIG. 4 shows an outline of the first embodiment. This includes a width across flats portion 2 having one surface as a first surface 21 and the other surface as a second surface 22, and the width across flats of the workpiece W including a cylindrical portion 1 having a constant diameter along the axis Z. This is a method for measuring the degree of symmetry S of the portion 2 with respect to the cylindrical portion 1. FIG.

A plane parallel to the first surface 21 and the second surface 22 and containing the axis Z of the cylindrical portion 1 is defined as a cylindrical portion center surface 100, a distance between the first surface 21 and the cylindrical portion center surface 100 is defined as A distance A, The distance between the two surfaces 22 and the center surface 100 of the cylindrical portion is defined as B distance B. Further, a vertical direction G is defined as a top-to-bottom direction with respect to the groove 4 when the groove 4 is horizontally formed so that two planes having the same width intersect each other at the same angle.

At this time, the first surface 21 or the second surface 22 is parallel to the vertical direction G, and the cylindrical portion 1 of the work W is placed in the groove portion 4 so as to abut along the axis Z, and the deepest portion of the groove portion 4 is placed. A plane parallel to the vertical direction G including the connecting straight line is taken as the central plane 100 of the cylindrical portion, and the A distance A and the B distance B are measured, and the absolute value of the difference between the two values is obtained. This absolute value is the degree of symmetry S. Thus, only the A distance A and the B distance B are required to be measured in the first embodiment.

Description will be made with reference to FIG. FIG. 4 is a schematic sectional view of the cylindrical portion 1 when the cylindrical portion 1 including the width across flats portion 2 of the workpiece W is placed on the groove portion 4 placed on the horizontal plane, and the cylindrical portion 1 is cut along a plane orthogonal to the axis Z. be. This groove portion 4 is a part of a V-shaped receiving jig which is formed in a regular V shape so that two planes of the same width intersect at the same angle. The straight line connecting the deepest part of the groove part 4 and the axis Z of the cylindrical part 1 overlap in the vertical direction G in the sectional view, and the plane including both is known as the datum center plane. Therefore, it is only necessary to measure the distances between the cylindrical portion center plane 100, which is the obtained datum center plane, and each surface of the width across flat portion 2, that is, the A distance A and the B distance B. FIG.

Hereinafter, a description will be given using mathematical formulas with reference to FIG. 4 .
<Definition 1.1> The thickness of the width across flats portion 2 is defined as 2R. At this time, R is equal to the half value of the thickness of the width across flats 2 (the distance from each surface of the width across flats portion 2 to the width across flats central plane 200 described later).
<Definition 1.2> The center plane of the width across flat portion 2 (a plane parallel to and equidistant from each surface of the width across flat portion 2 ) is defined as a width across flat center plane 200 .
<Definition 1.3> The distance between the center plane 200 of the width across flats and the center plane 100 of the cylindrical portion is defined as a misalignment amount δ (delta).

At this time, the following (formula 1.1) and (formula 1.2) are established. Here, (Formula 1.4) is derived by transforming (Formula 1.2) into (Formula 1.3). From this, the absolute value of the difference between the values of the A distance and the B distance is the value of the degree of symmetry S (equation 1.41).

δ=S/2 (Formula 1.1)
δ=AR (Equation 1.2)
δ=A−R=A−[(A+B)/2]=(A−B)/2=S/2 (Formula 1.3)
S=A−B (Formula 1.4)
S = | AB | (Equation 1.41)

[Effect of the first embodiment]
By adopting the first embodiment and introducing a dedicated measuring jig having a groove and a measuring instrument, it is possible to measure the width across flats of a workpiece including a cylindrical portion whose diameter is constant along the axis. It becomes possible to easily measure the degree of symmetry with respect to the cylindrical portion, which is useful for suppressing increases in manpower and man-hours. In addition, it is possible to flexibly cope with various types of workpieces by providing several kinds of dimensional variations of the grooves that serve as the workpiece receiving parts, which can be easily exchanged.

(Second embodiment)
Next, even if symmetry measurement is performed faithfully according to the symmetry measurement principle of the first embodiment, it is not necessary to configure the mechanism itself of the measuring instrument according to the symmetry measurement principle. A first aspect (second embodiment) of the present invention for obtaining the degree of symmetry of the width across flats portion 2 will be described.

5-6 show a schematic of the second embodiment. A width across flats portion 2 of a workpiece W including a cylindrical portion 1 having a constant diameter along an axis Z and including a width across flats portion 2 having one surface as a first surface 21 and the other surface as a second surface 22 The method of measuring the degree of symmetry S with respect to the cylindrical portion 1 is the same as in the first embodiment.

A plane parallel to the first plane 21 and the second plane 22 is collectively referred to as a reference plane 3, and the distance between the first plane 21 and one of the reference planes 3 in contact with the outer surface of the cylindrical portion 1 on the side closer to the second plane 22 is a first distance E, and the distance between the second surface 22 and one of the reference surfaces 3 in contact with the outer surface of the cylindrical portion 1 closer to the first surface 21 is a second distance F, the first distance E and A second distance F is measured and the absolute value of the difference between the two values is obtained. Thus, only the first distance E and the second distance F are required to be measured in the second embodiment.

Description will be made with reference to FIG. As shown in FIG. 5, in the second embodiment, one side (eg, first side 21) of the width across flats portion 2 of the work W is placed on the horizontal surface of a receiving jig having a horizontal surface, and the cylindrical portion 1 on the opposite side is placed. The distance from the reference plane 3 in contact with the outer surface of is obtained (first distance E) (Fig. 5(a)). Subsequently, the cylindrical portion 1 is turned over, the surface opposite to the width across flats portion 2 (eg, the second surface 22) is placed, and the same operation is repeated (second distance F) (FIG. 5(b)). Finally, the absolute value of the difference between the values of the first distance E and the second distance F (|EF|) is the value of the degree of symmetry S.

A description will be given below using a formula with reference to FIG. 6 . Part of the description of the first embodiment (paragraphs [0018] to [0020]) is also referred to.
<Definition 2.1> Let D be the outer diameter (diameter) of the cylindrical portion 1 .
<Definition 1.2> Reiterated A center plane of the width across flats portion 2 (a plane parallel to and equidistant from each surface of the width across flats portion 2 ) is defined as a width across flats center plane 200 .
<Definition 2.2> Cylindrical portions close to each surface of the ideal width across flats portion 2 with a degree of symmetry of 0 (when the center plane 200 of the width across flats coincides with the center plane 100 of the cylindrical portion) Let K be the distance to the reference plane 3 that is in contact with the outer surface of 1 .
<Definition 1.3> Reiterated The distance between the center plane 200 of the width across flats and the center plane 100 of the cylindrical portion is defined as the misalignment amount δ (delta).

At this time, the following (formula 2.1) and (formula 2.2) are established. If (2.1) and (2.2) are combined into (2.3), it can be transformed into (2.4), leading to (2.5). Here, since (Equation 1.1) shown again can be transformed into (Equation 1.11), (Equation 2.6) is derived. From this, the absolute value of the difference between the values of E and F is the value of the degree of symmetry S (equation 2.61).

D=E+δ+K (Formula 2.1)
D=F−δ+K (Formula 2.2)
E+δ+K=F−δ+K (Formula 2.3)
E+δ=F−δ (Formula 2.4)
2δ=FE (Equation 2.5)
δ=S/2 (formula 1.1) reprinted 2δ=S (formula 1.11)
S = (2δ =) FE ... (Formula 2.6)
S = | EF | (Equation 2.61)

For example, in the case of "E<F", it can be said that "the degree of symmetry S is equal to the length of F when the length of E is 0 (zero)". If the second measurement is performed after adjusting to zero, the measured value can be grasped directly as the value of the degree of symmetry S, which is convenient (Fig. 5).

[Effect of Second Embodiment]
By adopting the second embodiment and introducing a simpler dedicated measuring jig equipped with a receiving jig and a measuring instrument, it is possible to measure two workpieces including a cylindrical portion having a width across flats portion and a constant diameter along the axis. The degree of symmetry of the surface width portion with respect to the cylindrical portion can be measured more easily than in the first embodiment, which is useful for suppressing an increase in manpower and man-hours. In addition, even if a dedicated measuring jig is manufactured, it does not take up much space, and it is highly convenient because it can be used regardless of variations in workpiece dimensions.

(Other embodiments)
In the above-described embodiment, it is assumed that the degree of symmetry is manually measured using a simple dedicated measuring jig or the like, but the embodiment of the present invention is not limited to this. The symmetry measurement may be automated, for example by a robot.

As described above, the present invention is not limited to the above embodiments, and can be implemented in various forms without departing from the scope of the present invention.

Reference Signs List 1 Cylindrical portion 2 Width across flats portion 21 First surface 22 Second surface 3 Reference surface E First distance F Second distance Z ··shaft

Claims (2)

A cylindrical portion (1) having a constant diameter along an axis (Z), including a width across flats portion (2) having one surface as a first surface (21) and the other surface as a second surface (22) A method for measuring the degree of symmetry of the width across flats portion of a workpiece with respect to the cylindrical portion,
A plane parallel to the first plane and the second plane is collectively referred to as a reference plane (3),
A first distance (E) is defined as a distance between the first surface and one of the reference surfaces in contact with the outer surface of the cylindrical portion on the side closer to the second surface;
When the distance between the second surface and one of the reference surfaces in contact with the outer surface of the cylindrical portion on the side closer to the first surface is defined as a second distance (F),
Measuring the first distance and the second distance and determining the absolute value of the difference between the two values;
Two-sided width symmetry measurement method. A cylindrical portion (1) having a constant diameter along an axis (Z), including a width across flats portion (2) having one surface as a first surface (21) and the other surface as a second surface (22) A method for measuring the degree of symmetry of the width across flats portion of a workpiece with respect to the cylindrical portion,
A plane parallel to the first plane and the second plane and containing the axis of the cylindrical section is defined as a cylindrical section center plane (100),
The distance between the first surface and the center surface of the cylindrical portion is A distance (A),
The distance between the second surface and the center surface of the cylindrical portion is B distance (B), and
When the vertical direction (G) is the vertical direction with respect to the groove (4) formed so that two planes of the same width intersect each other at the same angle, when the groove (4) is horizontal,
The work is placed in the groove so that the first surface and the second surface are parallel to the vertical direction, and the cylindrical portion of the work is in contact along the axis, and the distance A and the distance B are set. Measure and find the absolute value of the difference between the two values,
Two-sided width symmetry measurement method.

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