JPS5832642B2 - Partial circular shape dimension measuring instrument - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shape and dimension measuring instrument for accurately and quickly measuring and recording the shape and dimensions of a partial circle at the corner of a stepped shaped component such as a rotating shaft.

Corners of rotating shafts, especially stepped parts such as crankshafts that are subject to heavy loads, are prone to breakage due to concentration of stress, so it is important for quality control to measure the shape accuracy of the corners after finishing by grinding etc. It has become an element.

For this reason, the current situation is that it is necessary to manage the total number of products to promote stability and improvement of quality, rather than just removing the horizontal lids as in the past.

Conventionally, the following two methods have been adopted to measure the shape and determine the accuracy of this corner partial circle.

Method 1 Use the "R Gauge" to judge whether there is a "gap" and its size.

Method 2: Enlarge and record the shape using a "precision type" detector linear shape measuring device, and judge based on the recorded figure.

However, in the case of method 1, the measurement work is very simple, /w
+(-U) can be easily and quickly performed, but the size of the "gap" is not quantitative, and the state of the shape (shape distortion, presence of minute steps) cannot be grasped at all, so corner At present, only very unreliable results can be obtained not only when modifying the shape but also when determining pass/fail.

On the other hand, in the case of method 2, since the measurement result can be determined from the enlarged recorded figure, anyone can easily quantitatively determine the condition and dimensions of the shape, so very reliable results can be obtained. .

However, because it is a precision type, it is necessary to prepare the measurement environment conditions, and because the stylus moves straight, the corner formed at the orthogonal part of two surfaces (one plane and the cylindrical surface in the case of a cylindrical shape) When measuring the shape of a partial circle, align the generatrix direction of the measuring surface of the object to be measured with the moving direction of the stylus, and then tilt it at 45 degrees (the conical surface of the tip of the stylus interferes with the vertical plane). This is because the stylus cannot accurately measure the shape of the stylus, and the slope that the stylus can smoothly follow is at most 70 degrees, and if the stylus is more than that, it will get stuck and cannot be measured.

) It becomes necessary to move the stylus accurately on the generatrix line, which increases the size of the device, and if the axis of the object to be measured spans multiple locations, such as a crankshaft, it takes a considerable amount of time to install the object to be measured. become.

Therefore, although it is suitable for spot inspection, it is inconvenient for 100% inspection.

When trying to accurately record the shape of the corner formed by the end surface A and the cylindrical surface B of a shaft component as shown in FIG. 1 using a stylus-type measuring instrument, the direction of movement of the stylus is It must be exactly on the generatrix line as shown by the arrow (■), and the direction of movement of the stylus displacement as it moves must be within a plane including the generatrix line and the center line as shown by the arrow (■).

If this is measured in a state where it is deviated from the generatrix line (arrow ■■ or arrow ■), the accurate shape cannot be determined.

Therefore, with conventional linear measuring instruments, the direction of movement of the stylus is
It is necessary to perform work to match the direction, and an adjustment table is equipped for this purpose.

Since the shape of the object to be measured is limited by the shape of the adjustment table in this method, it is impossible to measure large objects.
For objects to be measured, such as crankshafts, which have multiple axes, the object must be repositioned each time the measurement location changes, which poses many problems in terms of work.

The present invention has a mechanism in which a stylus and a detector are attached to a rotating shaft, and measurement is performed by the rotational movement of the rotating shaft, and two reference planes and one
The shape of a partial circle at a corner is measured by providing several auxiliary reference surfaces and pressing these reference surfaces and auxiliary reference surfaces against the object to be measured.

There are various application examples for the arrangement of two reference planes, one auxiliary reference plane, and the rotation axis, and for adjusting the relative positions of the above components when the diameter of the object to be measured changes. When organized with emphasis on minimizing, the following two types can be categorized.

Basic Arrangement Configuration (I) When the diameter of the object to be measured changes, one of the two reference planes is moved in parallel.

In FIG. 2, a reference plane C2D intersecting at an angle 2a and a rotating shaft to which the detector 3 is attached are provided.

The axis O-O of the rotating shaft is parallel to the reference plane C, and is perpendicular to the reference plane C at the line formed by the intersection of the reference plane C and the reference surface (hereinafter referred to as the intersection line). The imaginary plane (not shown) is arranged so as to be orthogonal to the imaginary plane (not shown).

Furthermore, the reference plane C is the detectable range Z of the detector 3 (not shown in FIG. 2).

(described later in FIG. 4), the stylus 5 and the detector 3 are integrated into the surface C, except for displacement detection and rotational movement.

On the other hand, one of the reference surfaces C and D is made movable while maintaining the angle 2a (for purposes of explanation, the reference surface C is fixed and the reference surface is movable).

At this time, the amount of movement of the reference plane is displayed with the stylus 5 as the origin as shown in the figure.

Furthermore, in order to include the end surface A of the partial circle composed of the end surface A and the cylindrical surface B in FIG. 1 within the detectable range Z, the auxiliary reference surface (
Not shown.

) will be provided.

The detectable range Z of the detector 3 refers to the detectable range Z of the detector 3 within the virtual circle drawn by the tip of the stylus 5 centering on the point O as the rotation axis rotates in FIG. Let a be the virtual circle that represents each limit value in the range.
, b, and a virtual circle a.

Let the range surrounded by b be the detectable range Z.

In FIG. 4, line gh, which connects two orthogonal straight lines with a partial circular arc, indicates a partial circle at the corner formed by cylindrical surface B and end surface A in FIG. The straight line part f is drawn based on the cylindrical surface B, and the straight line part e - h is drawn based on the end surface A based on the trajectory (2).

Further, the point of contact f between the virtual circle a and the line gh is a point set by the reference plane C described above, and the point of contact e is determined by the auxiliary reference plane described later.

Note that in FIG. 4, points e and 4 are both drawn in contact with the virtual circle a, but as long as these two points (partial circular shape e-f) are within the detectable range Z, they can be used in the present invention. There is nothing functionally wrong with that.

Next, the auxiliary reference plane will be explained.

The object of the present invention is to obtain a partial circular shape e −f in FIG.
The objective is to measure the partial circular shape e-f.
is included in the detectable range Z.

In this configuration, as described above, the reference plane C is within the detectable range Z, the rotation axis 0-0 (point O in Fig. 4) and the arrangement of the reference plane C are fixed, and the reference plane C is Since this is a method of measuring by pressing the cylindrical surface B (FIG. 1) against the cylindrical surface B (FIG. 1), the line g-f shown in FIG. 4 is included in the reference plane C during measurement.

This shows that the distance 11 is fixed in FIG. 4, and that the point f of the partial circle f-e is definitely within the detectable range Z.

Similarly, in order to place point e within the detectable range Z, it is necessary to fix the distance 12 between the axis O-O and point e during measurement, and as a means for this, an auxiliary reference plane is provided.

The auxiliary reference plane generally refers to the end surface A (
The surface in contact with the line e-h in FIG. 4 refers to the end surface of a stopper provided to fix the distance 12 from the axis O-O (in the embodiment described later, the end surface E of the movable piece 8).

If the above-mentioned 12 can be fixed, the contact surface of the auxiliary reference surface is not limited to the end surface A in FIG. It is safe to use.

Further, in this configuration, for the purpose of explanation, the stopper is assumed to be in surface contact with the end surface of the object to be measured, but the same effect can be obtained whether it is a point contact or a line contact.

Next, a method for measuring the basic arrangement (I) will be explained.

Cylindrical surface B with a diameter of 2R shown in Figures 1 and 2
When measuring a partial circle, first L = R/tan
Move the reference surface to position a, and change the reference surfaces C and D to the cylindrical surface B.
When the auxiliary reference surface (not shown) is pressed against the end surface A, as is clear from FIG. When the detector 3 with the stylus 5 is rotated about the axis O-O in this state, the locus of the stylus 5 will always run on the generatrix line, and can be as shown in (1) and (2) in FIG.

Next, in Fig. 2, when the diameter changes from 2R to 2R', the reference plane becomes the reference plane d, and the L indicating the amount of movement becomes L', and if L'=R'/tana, then always The stylus 5 is at a position in contact with the cylindrical surface, and the trajectory can always be a predetermined one.

In addition, in the examples described later, 2a is used to simplify the measurement.
= 90°, and L = R/tana -R.

Next, in the present invention, the reference surface C is fixed and the reference surface is movable, but the same effect can be obtained in the opposite case, that is, when the reference surface C is movable and the reference surface is fixed. However, if the diameter of the object to be measured changes from 2R to 2R', the amount of movement of the reference plane C is changed from L to L' on the reference plane (not shown), and at the same time, the position of the stylus 5 is changed from the reference plane. It is necessary to move from L to L' on plane C.

Furthermore, in the present invention, one of the two reference surfaces is movable, but when both surfaces are fixed, that is, when the reference surface C and the reference surface are fixed, the diameter of the object to be measured is When the position changes from 2R to 2R', the same effect can be obtained by moving the position of the stylus 5 from L to L' on the reference plane C.

Basic Arrangement Configuration (II) This is a configuration in which the angle of one of the two reference planes is changed when the diameter of the object to be measured changes.

In Fig. 3, the configuration of the two reference planes C and D, the rotation axis, and the auxiliary reference plane, and the axis 0-01 of the stylus 5 with respect to the reference plane C,
The relationship of the detector 3 is similar to the basic arrangement U).

Here, the distance Lo from the line of intersection between the reference plane C and the reference plane to the stylus 5 is constant, and between the reference planes C and D with the intersection line as the axis,
Either one is movable (for the purpose of explanation, the reference surface is movable and the reference surface C is fixed).

At this time, the angle formed by the reference plane C and the reference plane is defined as 2a.

In FIGS. 1 and 3, when measuring the portion of the cylindrical surface B (diameter 2R), first, the reference is set at the position of 2 a = 2 jan-1R/Lo.

Next, when the reference surfaces C and D are pressed against the cylindrical surface B and the auxiliary reference surface (not shown) is pressed against the end surface A, the stylus 5 is brought into contact with the cylindrical surface B, as shown in FIG. When the detector 3 with the stylus 5 is rotated about the axis O-O, the locus of the stylus 5 always runs on the generatrix line, and as shown in Fig. 1,
■' could be.

Next, in Fig. 3, when the diameter changes to 2R, 2R', the reference plane becomes the reference plane d, and the angle 2a indicating its inclination
becomes 2 a' and 2'a'= 2 j a n= R'
/L.

If so, the stylus 5 is always in a position in contact with the cylindrical surface, and the trajectory can always be a predetermined one.

The basic arrangement (I) of the present invention will be explained below based on one embodiment.

As shown in FIGS. 5 and 6, the main parts of this measuring instrument include a detector 3 attached to a rotating shaft 2 within the measuring instrument body 1;
An arm 4 extending from the detector 3, a stylus 5 attached to its tip, and a fixed reference piece 6 attached to the end of the measuring instrument body 1.
, a movable reference piece 8 integrated with a cylinder 7 incorporated into the measuring instrument body 1, and a set screw 9 attached to the cylinder 7 for operating the movable reference piece 8 from the outside.

Note that the stylus 5 rotates together with the detector 3 and arm 4 as the rotating shaft 2 rotates.

The fixed reference piece 6 has a reference surface C aligned with the rotation axis O-O of the rotation shaft 2.
The measuring instrument main body 1, which is separate from the rotating shaft 2, is placed at a position parallel to the reference plane C and within the detectable range Z (FIG. 4) of the stylus 5.

On the other hand, the movable reference piece 8 has a reference surface perpendicular to the rotation axis O-O of the rotating shaft 2 (that is, perpendicular to the reference surface C of the fixed reference piece 6).
In addition, the end surface E (Fig. 6) is used as the auxiliary reference surface, and the extension of the end surface E (auxiliary reference surface) is the detectable range Z of the stylus 5.
The measuring instrument body 1 is disposed via a cylinder 7 from the measuring instrument body 1 so that it can be moved while maintaining a state perpendicular to the fixed reference piece 6.

In this embodiment, the reference plane C of the fixed reference piece 6 is fixed on the line g-f including the point f on the virtual circle a shown in FIG. 4, and the end face E (auxiliary reference plane) of the movable reference piece 8 is By fixing it on the line h - e that includes point e on the virtual circle a, the partial circular shape f of the corner is
-Measure e.

Next, the measurement method of this example will be explained.

In FIGS. 1 and 5, first, the diameter of the cylindrical surface B is determined by actual measurements or drawing dimensions.

If the obtained dimension is 2R, move the movable reference piece 8 to the position L=H.

In addition, when setting the distance, the reference surface of the movable reference piece 8 is the stylus 5.
Since the scale 10 is pre-marked on the measuring instrument body 1 with the position corresponding to the tip of the pointer 10 as the base point, the adjustment is made by operating the set screw 9 via the cylinder 7 and adjusting the tip of the pointer 11 integrated with the movable piece 8. is aligned with the dimension R of the scale 10.

After setting the movable reference piece 8 in the above method, the reference surfaces C and D of each reference piece are pressed against the cylindrical surface B, and the end face E (
The measurement is performed by pressing the auxiliary reference surface) against the end surface A and then driving the rotating shaft 2.

Furthermore, the trajectory of the stylus 5 and its displacement are determined, for example, by
If you convert it to a recorder and draw an enlarged record, line g in Figure 4
- A shape and size record obtained by enlarging h as it is.

As described above, the present invention consists of a measurement mechanism that performs measurement by rotational movement using a rotating shaft 2 to which a stylus 5 and a detector 3 are attached, two reference surfaces C and D, and one auxiliary reference surface. , keeping the relationship between the reference plane C and the rotation axis 2 constant, and
, D and an auxiliary reference surface are pressed against the object to be measured to measure a partial circular shape.

Therefore, whereas conventional precision detector linear measuring instruments take measurements by placing the object to be measured on an adjustment table,
In the present invention, since the measuring device is pressed against the object to be measured for measurement, there is no need for an adjustment table, and the measuring device is smaller and lighter than conventional measuring devices.

Furthermore, since there is no need to place the object to be measured on an adjustment table, there are no restrictions on the shape of the object to be measured, making it particularly suitable for measuring large objects or objects having a plurality of axes.

Furthermore, when measuring multiple objects of the same shape, it is no longer necessary to place each object on an adjustment table and match the measurement direction, so the time required for measurement work is reduced compared to conventional measurement methods. Because the process is extremely short, parts management that previously had to rely on strip inspection can now be carried out in the same amount of time as 100% inspection, making it extremely useful industrially from a quality control perspective. be.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the relationship between the trajectory of the stylus and the object to be measured.
The figure shows the principle of the basic arrangement (1), Fig. 3 shows the principle of the basic arrangement (It), Fig. 4 is an enlarged view showing the relationship between the partial circle and the detectable range, and Fig. 5 shows the example. The front view, FIG. 6, is a left side view of FIG. 2...Rotation axis, 3...Detector, 5...
...Stylus, 6...Fixed reference piece, 8...
...Movable reference piece.

Claims (1)

[Claims] 1 A measurement mechanism that performs measurement by rotational movement using a rotating shaft 2 to which a stylus 5 and a detector 3 are attached, and two reference planes C.
. The reference plane C,
D is fixed, the other is movable, and the reference plane C2
A partial circular shape dimension measuring instrument characterized in that measurement is carried out by pressing D against the cylindrical surface of the object to be measured and pressing an auxiliary reference surface against the end of the object to be measured.