JP3179264B2 - Alignment measurement device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring a run-out of a rotating body such as a V-pulley having a V-shaped groove without being affected by run-out.

[0002]

2. Description of the Related Art In general, an injection molded product is often used for a V pulley having a V-shaped groove formed on a circumferential surface used in a rotation transmission system of a tape recorder or the like. When a V-pulley is formed by injection molding, the V-pulley is molded using a pair of molds. Therefore, if the abutment state of the molds is slightly deviated, the molded product will have a core runout or a surface runout. .

The deviation occurs when the center (axis) of the formed V-pulley is out of the designed value. When the deviation is not within the allowable range (usually, plus or minus about 10 μm). Becomes defective. In order to manufacture a non-defective product, the mold must be finely adjusted so that the run-out is within an allowable range. Prior to such mold adjustment, the centering measurement is performed.

FIG. 11 shows an example of a conventional misalignment measuring device 10. The above-described V pulley is shown as the rotating body to be measured. Reference numeral 12 denotes a measurement base, on which a measurement base 1 is provided.
4 is placed, and a shaft insertion hole 1 is
The shaft mounting base 16 in which 7 is bored is fixed.

On the other hand, reference numeral 20 denotes a rotating body to be measured. In this example, a V-pulley having a V-shaped groove 21 formed on its outer peripheral surface is exemplified. V pulley 2
The shaft 22 is inserted through the shaft mounting base 16 as shown in the figure.

In this state, the detector 2 is placed at the bottom p of the V-shaped groove 21.
4 is lightly abutted (see the figure), and the V pulley 20 is rotated in the abutted state. As the detector 24, an electric micrometer probe or the like is used.

If the V-pulley 20 is misaligned, the radius R from the axis qq 'fluctuates as indicated by the arrow a depending on the rotational position of the V-pulley 20, as shown in FIG. It is detected by the detector 24. The quality is determined based on the detection data (measurement data) detected by the detector 24.

[0008]

When a V-pulley is formed by injection molding, as described above, depending on the abutting state of the mold, there may be a run-out in addition to a center run-out. When the V-pulley 20 having runout is measured by the runout measuring device 1 shown in FIG. 11, the runout affects the runout measurement.

For example, when there is a run-out in the molded product, and this is formed with the axis inclined at an angle θ with respect to the reference axis qq ′ as shown in FIG. In the position, as shown in FIG.
Abuts on the V-shaped groove 21 in a state of being separated from the bottom p of the V-shaped groove 21.

If the detector 24 comes into contact with the bottom part p by a distance Δp, this is measured in the same way as the occurrence of misalignment by Δp. Therefore, if there is a surface deviation, this affects the measurement of the center deviation, and the center deviation cannot be measured accurately. This is exactly because the measurement is performed with the shaft 22 fixed to the shaft mounting base 16.

Accordingly, the present invention has been made to solve the above-mentioned conventional problems, and is intended to solve the problem of the prior art. Is proposed.

[0012]

In order to solve the above-mentioned problems, in the present invention, sliders are mounted on a pair of bases so as to be able to move forward and backward, respectively, and V-shaped bearings are respectively mounted on these sliders. The V-shaped bearing is attached and fixed, and the shaft attached to the rotating body to be measured is passed over the rotating body to be measured, and the eccentricity detector is brought into contact with the rotating body to be measured. The rotational deviation of the object to be measured is measured by the rotational deviation detector while rotating.

[0013]

As shown in FIG. 13, the detector 24 comes off the V-shaped groove 21 when there is a run-out. At this time, since a slight pressing force is applied to the V-shaped groove 21, if the shaft 22 is supported in a free state as shown in FIG. 1, this biased pressing force (particularly, a component force parallel to the shaft 22) is applied. The shaft 22 moves in either direction.

At this time, the shaft 22 moves and stabilizes until the tip 25 of the detector 24 reaches the bottom p of the V-shaped groove 21. This state is the same as the state where the runout is zero. Therefore, even if there is a surface deviation, it is possible to measure the core deviation without being affected by the deviation.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A case where an example of the eccentricity measuring apparatus according to the present invention is applied to the eccentricity measurement of a V-pulley will be described in detail with reference to the drawings.

FIG. 1 is a plan view showing an example of a misalignment measuring apparatus 1 according to the present invention. FIG. 2 shows a top view of the apparatus and FIG. 3 shows a partially sectional side view. Explaining this, the components of the misalignment measuring device 1 are all made of steel such as brass.

The eccentricity measuring apparatus 1 has a pair of rectangular bases (tables) 30 and 31 arranged so as to face each other with a predetermined distance therebetween. Rails 32, 33 having a rectangular cross section parallel to the facing direction are attached and fixed to the holding plates 32a, 32b, 33a, 33b and well-known means (not shown) such as screws (see FIG. 1).

The rails 32, 33 are provided with sliders 34, 35 which slide with the guides as guides. The cross sections of the sliders 34 and 35 are inverted U as shown in FIG.
A rail-shaped piece, a rail 32, 33 and a slider 3
The friction coefficient between the sliders 34, 35 is designed to be very small, and even if a slight force is applied to the sliders 34, 35, the sliders 34, 35 in the pressing direction (the left-right direction in the figure).
35 slides.

The auxiliary members 3 are provided on the upper surfaces of the sliders 34 and 35.
6, bearings 38, 39 each having a V-shaped groove as shown in FIG. This bearing 38,3
A shaft 22 inserted through a V pulley 20, which is a rotating body to be measured, as shown in FIG. An auxiliary pulley 44 for rotating and driving the V pulley 20 is further inserted through the shaft 22.

As shown in FIG. 1, a drive motor 40 is fixed to one of the bases 30, and a shaft pulley 42 is attached to a rotary shaft 41 thereof. Is attached to the V-pulley 20 so that the V-pulley 20 is driven to rotate at a predetermined speed during the misalignment measurement.

As will be described later, when there are many measurement points on the V-pulley 20, the rotation speed of the V-pulley 20 needs to be reduced, so that the auxiliary pulley 44 preferably has a larger diameter.

The pair of bases 30 and 31 are connected to each other by a holding plate 46 in order to keep the distance between the bases 30 and 31 constant.
The size of the misalignment measuring device 1 is determined according to the size of the member to be measured.

In the misalignment measuring apparatus 1 constructed as described above, a shaft 22 having a predetermined length is attached to the V-pulley 20, which is a member to be measured, and the shaft 22 is connected to a bearing 38 as shown in FIG. , 39. A rotational force is transmitted to the auxiliary pulley 44 from the drive motor 40.

The V-shaped groove 21 of the V-pulley 20 is brought into contact with the tip 25 of a detector 24 as shown in FIG. 11, and by rotating the V-pulley 20 at a predetermined speed.
Is measured. During this misalignment measurement, V pulley 2
When there is a run-out at 0, the tip 25 of the detector 24 acts so as to separate from the bottom p of the V-shaped groove 21 as in the prior art.

When the tip 25 of the detector 24 is separated from the bottom p of the V-shaped groove 21, the component (parallel to the shaft 22) of the load (pressing force) applied to the V-shaped groove 21 from the detector 24 at that time. , The shaft 22 tends to move in the direction of the component force. The shaft 22 and the bearings 38 and 39 on which the shaft 22 is mounted are substantially integrated in the axial direction by the force of the belt 47 pulling the auxiliary pulley 44 downward, and the component force on the shaft 22 is transmitted to the sliders 34 and 35.
Since the sliders 34 and 35 are free in the axial direction, the sliders 34 and 35 slide in the same direction as the component force until the component force becomes zero.

By this sliding operation, the tip 25 of the detector 24 is directed to the bottom p of the V-shaped groove 21. When the tip 25 reaches the bottom p, the component force becomes zero, and the runout becomes zero. . Therefore, even if there is a run-out, the tip 25 of the detector 24 is always located at the bottom p of the V-shaped groove 21, and the run-out has no effect on the run-out measurement.

Since the sliders 34 and 35 can be slid in either direction, the V-pulley 20 can be automatically corrected to have no run-out regardless of the run-out. Can avoid the influence of

Next, a specific example of the deviation measurement will be described. When the V pulley 20 is formed by injection molding, a pair of dies is usually used as described above. As shown in FIG. 4, cavities 50a, 51 for the V pulley 20 are respectively provided in a pair of molds (actually, slide cores) 50, 51.
a are formed and each is abutted as shown. When the abutment is complete, a step 5 between the two dies 50 and 51 is required.
4 (FIG. 5) does not occur.

However, in most cases, the molds 50 and 51 cannot be abutted with the step 54 being zero (ΔL = 0), so that the mold is always formed with the step 54 as shown in FIG. . Alignment also occurs due to the step 54. Therefore, with the step 54 as small as possible, the core pin 55
(For forming the shaft hole of the V pulley 20) or the slide core 50,
The position of 51 will be strictly adjusted.

In measuring the center deviation, a measurement including the step is performed. Therefore, it is necessary to specify the position of the step from the measurement data obtained first. The step is generated at two points 180 ° opposite each other, and when there is a step, the position of the step is determined in consideration of the fact that the difference between the measurement data before and after the step becomes large.

The mold 5 depends on the level difference.
The amount of collision correction of 0,51 changes. Since the position of this step needs to be calculated accurately, several hundred points are taken around the outer periphery of the V pulley 20 and these are set as measurement points. In this example, 360 points are set so as to be measurement points of 1 °. The larger the number of measurement points, the more accurately the position of the step can be determined. For example, about 500 points can be used.

As a measurement start point of the V-pulley 20, for example, a molding model number formed on a part of the peripheral surface of the V-pulley 20 is determined as a temporary point (point S in FIG. 7), and an axis (O-
The measurement of the center deviation is started from O ′). FIG. 6 shows an example of the measurement result at that time. FIG. 6 shows typical angles (3 in the figure).
0 °) is shown in an expanded manner.
FIG. 7 also shows representative measurement data on the basis of the curve Lb in which the run-out is zero. Curve La is the misalignment measurement curve, which is the same as FIG.

In order to find a step, for example, as shown in FIG. 8A, a difference between the preceding and following measurement data exceeding the first limit value (reference value) is extracted, and the difference is further extracted from the extracted measurement data to the next limit value. The limit value is gradually increased so that a value exceeding the value is extracted, and the last change point of the measurement data is defined as the abutting end face at which the step is generated. In this case, as shown in FIG. 8A, a changing point where Y / X is large is selected as the step. FIG. A is normalized as shown in FIG.

As a result of the calculation as described above, when the points t and u are selected as the abutting end faces having a step as shown in FIG. 7, a line xx connecting the t and u is a reference line (abutting end face). Used as For the magnitudes ΔL1 and ΔL2 of the step 54, (Δ
(L1 + ΔL2) / 2 is the correction amount of the dies 50 and 51.
When the step is as shown in FIG. 5, the mold 50 is shifted in the s direction by (ΔL1 + ΔL2) / 2, and the other mold 5 is shifted.
1 is also corrected by shifting in the r direction by (ΔL1 + ΔL2) / 2. Specifically, the correction is made by cutting or thickening the contact surfaces of the slide cores 50 and 51 and the slider (not shown) that comes into contact with the slide cores.

At the same time as the calculation of the step, the correction amount of the center deviation is calculated using the above-mentioned measured data. Although the run-out can be measured using the V-pulley 20 formed after correcting the step, the former is exemplified in this example.

In order to measure the misalignment, for example, as shown in FIG. 7, corresponding measurement data is extracted every 30 ° (= n) from a new reference line xx, and a step is added to the extracted 12 measurement data. Is calculated, and the center of gravity G (xG, yG) determined by the measurement data in which the amount of correction of the step is added is calculated, and the difference between the calculated center of gravity G and the original axis center is used as the amount of misalignment correction. Is done. n = 30 is an example.

The axial deviation correction amount is used as the above-mentioned axial deviation correction amount for the core pin 55. Correction of the core pin is performed by rebuilding the nest.

FIG. 9 shows an example of a circuit system of the measuring apparatus 1 used for measuring the level difference and the deviation. The measurement data detected by the detector 24 is passed through an amplifier 61 to an A / D converter.
The signal is supplied to a converter 62 and is converted into a digital signal of a predetermined number of bits.
The calculation of the step correction amount, the calculation of the center deviation correction amount, and the like are automatically performed by using the center deviation measurement program including the level difference measurement supplied to the step 3.

A rotation control signal for the drive motor 40 is generated from the CPU 63 via the driver 66. The rotation speed of the V pulley 20 and the like are determined by the rotation control signal. In synchronization with this rotation control signal, the timing of taking in the measurement data from the detector 24 at a predetermined measurement point is further determined.

Numeral 64 denotes a display unit (CRT, liquid crystal element, etc.) for displaying the measured data as shown in FIG. 6 or FIG. 7 and for displaying the calculation result, and 65 for printing the data. Printer.

The above-described step difference correction amount and center deviation correction amount are stored in a memory (RAM or the like) built in the CPU 63, and these are used as a mold correction amount or a correction amount for forming a mold.

FIG. 10 is an example of a flowchart showing a processing procedure for calculating the level difference correction amount and the center deviation correction amount.

When the above-described processing program is started,
First, from the temporary reference point OO 'shown in FIG.
= 360) (step 8)
1), a step determination process and a step correction amount are calculated from the measured data at the m points (step 82).

When the position of the step is determined, the position of the determined step is set as a reference axis (step 83), and measurement data for every n ° (n = 30) is extracted from the new reference point t. (Step 84), the (G / 360 ° / n °) +2) square center of gravity G in which the correction amount of the step is added is calculated (Step 85). When the measurement data is extracted every 30 °, the center of gravity G (xG, yG) of the dodecagon is obtained as a whole. The center of gravity G of the polygon is calculated by a well-known mathematical method.

In many cases, the eccentricity of the mold is generally eccentric, so that the calculated position of the center of gravity G is further ±± x, ±
By giving each correction value of Δy, a new center of gravity G ′ (xG ′, y
G ′) is calculated (step 86). Δx and Δy are about 1 μm. By giving this correction value, a total of four new centers of gravity G 'are obtained, and the difference in the x-axis and y-axis directions between the curve which is supposed to be drawn by these centers of gravity G' and the curve Lb with no centering is zero. Is used as the final center of gravity GO calculated from the measured data (step 87).

The difference (ΔxG, ΔyG) between the calculated center of gravity GO and the true axis becomes the amount of correction of the axis deviation (step 8).
8). The above-mentioned step difference correction amount is further added to the center deviation correction amount.

In the embodiment described above, the present invention is applied to the V pulley 2
Although the present invention is applied to the measurement of the run-out of 0, it can be easily understood that the rotating body to be measured can be applied to other than the V-pulley used in a tape recorder or the like.

[0048]

As described above, in the misalignment measuring apparatus according to the present invention, misalignment is measured with the shaft of the rotating body to be measured being free.

According to this, even if there is a run-out, the run-out can be measured with the run-out corrected so that the run-out becomes zero, so that the run-out of the rotating body to be measured is affected by the run-out. Can be measured without having to As a result, the measurement of misalignment and the measurement of the level difference can be performed more accurately than in the past, so that the accuracy of the molded product to be calibrated is greatly improved.

Therefore, since it has the feature that a highly accurate rotating body can be formed, it is extremely suitable for application to the measurement of misalignment of a pulley or other rotating body of a tape recorder which requires relatively strict accuracy of a molded product.

[Brief description of the drawings]

FIG. 1 is a plan view showing an example of a misalignment measuring device according to the present invention.

FIG. 2 is a top view of FIG.

FIG. 3 is a side view in which a part of FIG. 1 is sectioned.

FIG. 4 is a diagram showing an abutting state without a step.

FIG. 5 is a diagram showing an abutting state with a step.

FIG. 6 is an expanded view of an example of misalignment measurement data.

FIG. 7 is a diagram illustrating an example of misalignment measurement data.

FIG. 8 is a diagram showing an example of measurement data near a step.

FIG. 9 is a system diagram illustrating an example of a circuit system of the misalignment measuring device.

FIG. 10 is a flowchart illustrating an example of misalignment measurement.

FIG. 11 is an explanatory diagram of a conventional misalignment measuring device.

FIG. 12 is a diagram showing a deviation measurement.

FIG. 13 is a diagram showing an example of measurement of misalignment in a state including surface deviation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Alignment measuring device 20 V pulley 22 Shaft 32, 33 Rail 34, 35 Slider 38, 39 V-shaped grooved bearing

──────────────────────────────────────────────────続 き Continuation of the front page (56) References Japanese Utility Model 63-99204 (JP, U) Japanese Utility Model 48-84254 (JP, U) (58) Fields surveyed (Int. Cl. ⁷ , DB name) G01B 5/00-5/30 G01B 21/00-21/32

Claims (1)

(57) [Claims] 1. A slider is mounted on a pair of bases so as to be able to move forward and backward, and V-shaped bearings are respectively mounted and fixed on these sliders. The V-shaped bearings are mounted on the rotating body to be measured. The rotating shaft to be measured is contacted with the rotating body to be measured, and the shaft deviation detector is brought into contact with the rotating body to be measured. The core of the rotating body to be measured is rotated by the shaft rotating detector while rotating the rotating body to be measured. A core shake measuring device for measuring shake.