JPH07128003A - Runout measuring instrument - Google Patents

Abstract

PURPOSE:To measure runout without being affected by surface movement. CONSTITUTION:Sliders 34 and 35 are placed on a pair of substrates 3O and 31 so that they can move freely, V-shaped bearings 38 and 39 are mounted on the sliders 34 and 35. and a shaft 22 fitted to a rotator 20 to be measured is passed to the V-shaped bearings 38 and 39. A runout detection probe 24 contacts the rotator 20 and the core movement of the rotator 20 is measured by the runout detection probe while rotating the rotator 20. Since the detection probe 24 moves away from the V groove if the rotator 20 suffers from surface movement but the shaft 22 is in contact with the bearing in a free state, the shaft 22 moves in either left or right until the surface movement reaches zero. Therefore, the presence of surface movement does not affect the measurement of the surface movement.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a runout measuring device capable of measuring runout of a rotating body such as a V-pulley having a V-shaped groove without being affected by surface runout.

[0002]

2. Description of the Related Art In general, injection molded products are often used for V pulleys and the like having V-shaped grooves formed on their circumferential surfaces, which are used in the rotation transmission system of tape recorders. When forming the V-pulley by injection molding, the V-pulley is formed by using a pair of molds, so if a slight deviation occurs in the abutting state of the molds, a runout or runout of the molded product occurs. .

Runout occurs when the center (axial center) of the molded V-pulley deviates from the design value, and when runout is not within an allowable range (usually within plus or minus 10 μm). Will be defective. In order to manufacture it as a good product, the mold must be finely adjusted so that the runout falls within the allowable range. The runout measurement is performed prior to such die adjustment.

FIG. 11 shows an example of a conventional runout measuring device 10. The above-mentioned V pulley is shown as the rotating body to be measured. 12 is a measurement base, on the upper surface of which a measurement base 1
4 is placed, and the shaft insertion hole 1
A shaft mount 16 having a hole 7 is fixed.

On the other hand, 20 is a rotating body to be measured, and in this example, a V pulley having a V-shaped groove 21 formed on its outer peripheral surface is exemplified. V-pulley 2 when measuring runout
The shaft 22 is penetrated through 0, and the shaft 22 is fitted and fixed to the shaft mount 16 as shown in the figure.

In this state, the detector 2 is attached to the bottom p of the V-shaped groove 21.
The tip portion 25 of 4 is lightly contacted (see the figure), and the V pulley 20 is rotated in the contacted state. As the detector 24, an electric micrometer probe or the like is used.

When the V-pulley 20 has a center deviation, the radius R from the axis qq 'fluctuates as shown 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 judged based on the detection data (measurement data) detected by the detector 24.

[0008]

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

For example, when a molded product has a surface deviation and the molded product is formed with the shaft center inclined by an angle θ with respect to a standard shaft center qq 'as shown in FIG. At the position, as shown in FIG.
Comes into contact with the V-shaped groove 21 in a state of being separated from the bottom p of the V-shaped groove 21.

When the detector 24 comes into contact with the bottom portion p by a distance of Δp, this is measured in the same way as if the runout of Δp occurs. Therefore, if there is surface runout, this affects the runout measurement and the runout cannot be accurately measured. This is nothing but measurement because the shaft 22 is fixed to the shaft mount 16.

Therefore, the present invention solves such a conventional problem, and even if there is a temporary surface deviation, the surface deviation does not affect the measurement of the deviation. Is proposed.

[0012]

In order to solve the above-mentioned problems, according to the present invention, sliders are mounted on a pair of bases so as to be movable back and forth, and V-shaped bearings are respectively mounted on these sliders. The shaft fixed to the V-shaped bearing is attached to the rotating body to be measured, and the runout detector is brought into contact with the rotating body to be measured. It is characterized in that the core deviation of the rotating body for measurement is measured by the core deviation detector while rotating.

[0013]

As shown in FIG. 13, when there is a surface deviation, the detector 24 comes off the V-shaped groove 21. At this time, since a slight pressing force is applied to the V-shaped groove 21, when the shaft 22 is borne in a free state as shown in FIG. 1, this biased pressing force (particularly, the component force parallel to the shaft 22) causes The shaft 22 moves in either the left or right 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. In this state, the runout is the same as zero. Therefore, even if there is surface runout, the runout can be measured without being affected by it.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a case where an example of the runout measuring apparatus according to the present invention is applied to the runout 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 eccentricity measuring device 1 according to the present invention, with reference to FIG. 2 showing a top view thereof and FIG. 3 showing a side view with a part thereof cross-sectioned, respectively. To explain, the runout measuring device 1 uses steel materials such as brass for all its constituent parts.

The eccentricity measuring device 1 has a pair of rectangular bases (tables) 30 and 31 arranged so as to face each other with a predetermined distance therebetween, and the bases are provided at the central portions of the respective upper surfaces thereof. Rails 32 and 33 each having a square cross section parallel to the opposite direction are attached and fixed using pressing plates 32a, 32b, 33a and 33b and well-known means (not shown) such as screws (see FIG. 1).

Sliders 34 and 35 are attached to the rails 32 and 33 and slide using the rails as guides. As shown in FIG. 3, the sliders 34 and 35 have an inverted U-shaped cross section.
It is a V-shaped piece and has rails 32 and 33 and a slider 3.
The friction coefficient between the sliders 34 and 35 is designed to be extremely small, and even if a slight force is applied to the sliders 34 and 35, the sliders 34 and 35 move in the pressing direction (left and right direction in the figure).
35 is designed to slide.

The auxiliary member 3 is provided on the upper surfaces of the sliders 34 and 35.
6, 37 are attached, and bearings 38, 39 having V-shaped grooves as shown in FIG. 3 are attached to the mutually opposing side surfaces of the auxiliary members 36, 37. This bearing 38,3
A shaft 22 inserted through a V pulley 20 which is a rotating body for measurement as shown in FIG. An auxiliary pulley 44 for driving the V pulley 20 to rotate 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 of the base motor 30. A belt 47 is attached to the V-pulley 20 so that the V-pulley 20 is rotationally driven at a predetermined speed during measurement of runout.

As will be described later, when the V pulley 20 has a large number of measurement points, it is necessary to slow down the rotation speed of the V pulley 20. Therefore, it is preferable that the auxiliary pulley 44 has a large diameter.

In order to keep the facing distance between the pair of bases 30 and 31 constant, they are connected by a holding plate 46.
The size of the runout measuring device 1 is determined according to the size of the member to be measured.

In the eccentricity measuring device 1 thus constructed, 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 has a bearing 38 as shown in FIG. , 39. Rotational force is transmitted from the drive motor 40 to the auxiliary pulley 44.

The tip portion 25 of the detector 24 as shown in FIG. 11 is brought into contact with the V-shaped groove 21 of the V-pulley 20, and the V-pulley 20 is rotated by rotating the V-pulley 20 at a predetermined speed.
Runout is measured. During this runout measurement, V pulley 2
When there is surface deviation 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 conventional case.

When the tip 25 of the detector 24 separates from the bottom p of the V-shaped groove 21, the component force parallel to the shaft 22 in the load (pressing force) applied to the V-shaped groove 21 from the detector 24 at that time. , The shaft 22 tries to move in the direction of the component force. The shaft 22 and the bearings 38, 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 for the shaft 22 is transmitted to the sliders 34, 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 portion 25 of the detector 24 faces the bottom portion p of the V-shaped groove 21, and the component force is zero when the tip portion 25 reaches the bottom portion p, whereby the surface runout becomes zero. . Therefore, even if there is surface deviation, the tip portion 25 of the detector 24 is always located at the bottom p of the V-shaped groove 21, and the surface deviation has no influence on the core deviation measurement.

Since the sliders 34 and 35 can be slid to either the right or left direction, any surface deviation of the V pulley 20 can be automatically corrected so that the surface deviation becomes zero, and the surface deviation can be reduced. You can avoid the influence of.

Next, a specific example of the measurement of the runout will be described. When the V-pulley 20 is formed by injection molding, a pair of molds is usually used as described above. As shown in FIG. 4, a pair of molds (actually, slide cores) 50 and 51 have cavities 50a and 51 for the V pulley 20, respectively.
a are formed, and each abuts as shown. Step 5 between the two molds 50 and 51 when in perfect abutment
4 (FIG. 5) does not occur.

However, in most cases, the molds 50 and 51 cannot be abutted against each other in the state where the step 54 is zero (ΔL = 0), so that the step 54 is always formed with the step 54 as shown in FIG. . This step 54 also causes a runout. Therefore, with the step 54 made as small as possible, the core pin 55 should be adjusted so that the runout becomes small.
(For forming the shaft hole of the V pulley 20) or the slide core 50,
The position of 51 will be adjusted strictly.

When measuring the runout, the step including the step is measured. Therefore, it is necessary to specify the position of the step from the measurement data obtained first. The step is generated at two points facing each other by 180 °, and when the step is present, the position of the step is determined in consideration of the fact that the difference between the measurement data before and after the step is large.

The mold 5 depends on the level of the step.
The collision correction amount of 0,51 changes. Since it is necessary to calculate the position of this step accurately, the outer circumference of the V pulley 20 is set to several hundred points, and this is set as the measurement point. In this example, 360 points are set so that the measurement points are 1 °. The larger the number of measurement points, the more accurately the position of the step can be determined. Therefore, for example, about 500 points can be used.

As a measurement starting 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 set as a temporary point (point in FIG. 7 s), and an axial center (O-
Measurement of runout is started from O '). An example of the measurement result at that time is shown in FIG. Figure 6 shows typical angles (3 in the figure)
The measurement data for each 0 °) is expanded and shown,
FIG. 7 shows the same representative measurement data based on the curve Lb with zero center deviation. Curve La is a runout measurement curve, which is the same as in FIG.

In order to find the step, for example, as shown in FIG. 8A, a difference in measurement data before and after exceeds a first limit value (reference value) is extracted, and the difference in the extracted measurement data is further limited to the next limit. The limit value is gradually increased so that those exceeding the value are extracted, and the last remaining change point of the measurement data is set as the abutting end surface where the step is generated. In this case, a change point of large Y / X is selected as a step as shown in FIG. 8A. The figure A is normalized as shown in the figure B.

As a result of the calculation in this way, when the points t and u are selected as the abutting end faces having steps as shown in FIG. 7, the line xx connecting the t and u is the reference line (abutting end face). Used as. For the sizes ΔL1 and ΔL2 of the step 54, (Δ
L1 + ΔL2) / 2 is the correction amount of the molds 50 and 51.
When the step is as shown in FIG. 5, the die 50 is shifted in the s direction by (ΔL1 + ΔL2) / 2, and the other die 5
1 is also corrected by shifting in the r direction by (ΔL1 + ΔL2) / 2. Specifically, it is corrected by cutting or overlaying the contact surfaces of the slide cores 50 and 51 and sliders (not shown) that contact the slide cores.

Simultaneously with the step calculation process, the misalignment correction amount is calculated using the measurement data described above. Although it is possible to measure the runout using the V-pulley 20 formed after the step is corrected, the former is exemplified in this example.

To measure the runout, for example, as shown in FIG. 7, the measurement data corresponding to each 30 ° (= n) is extracted from the new reference line xx, and the extracted 12 measurement data are stepped. The center of gravity G (xG, yG) determined by the measurement data with the correction amount of the step difference is calculated, and the difference between the calculated center of gravity G and the original axis center is used as the misalignment correction amount. To be done. n = 30 is an example.

The misalignment correction amount is used as an axial correction amount for the core pin 55 described above. Correction of the core pin is done by rebuilding the nest.

FIG. 9 shows an example of the circuit system of the measuring device 1 used for measuring the step and the runout, and the measurement data detected by the detector 24 is passed through the amplifier 61 to the A / D converter.
The converted measurement data is supplied to the converter 62 and converted into a digital signal having a predetermined number of bits, and the converted measurement data is stored in the CPU 6
3 is provided, and calculation of a step difference correction amount, calculation of a center deviation amount, etc. are automatically executed by using the center deviation measurement program including the step measurement provided here.

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 is determined by the rotation control signal. In synchronism with this rotation control signal, the timing at which measurement data is taken in from the detector 24 at a predetermined measurement point is further determined.

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

The above-described step correction amount and misalignment 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 flow chart showing a processing procedure for calculating the step difference correction amount and the center deviation correction amount.

When the above processing program is activated,
First, from the temporary reference point OO ′ shown in FIG. 7, m points (m
= 360) and the measured data are obtained (step 8
1) A step determination process and a step correction amount are calculated from the measurement data of these m points (step 82).

When the position of the step is determined, the determined position of the 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) Then, the center of gravity G of the ((360 ° / n °) +2) polygon is calculated in consideration of the correction amount of the step (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 known mathematical method.

Since the mold forming is usually eccentric in many cases, ± Δx and ± are further added to the calculated position of the center of gravity G.
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 center of gravity G'is obtained, but the difference in the x-axis and y-axis directions between the curve that is supposed to be drawn by these center of gravity G'and the curve Lb with zero runout. The center of gravity G'that minimizes is used as the final center of gravity G0 calculated from the measured data (step 87).

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

In the embodiment described above, the present invention is applied to the V-pulley 2
Although it has been applied to the zero runout measurement, 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 runout measuring device according to the present invention, the runout is measured with the shaft of the rotating body to be measured being free.

According to this, even if there is a runout, the runout can be measured in a state where the runout is corrected to zero, so that the runout of the rotating body to be measured is affected by the runout. You can measure without As a result, it is possible to measure the center deviation and the step difference more accurately than in the past, and this has the feature that the accuracy of the calibrated molded product is greatly improved.

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

[Brief description of drawings]

FIG. 1 is a plan view showing an example of a runout 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 with no step.

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

FIG. 6 is a diagram showing an expanded example of misalignment measurement data.

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

FIG. 8 is a diagram showing an example of measurement data in the vicinity of a step.

FIG. 9 is a system diagram showing an example of a circuit system of the runout measuring device.

FIG. 10 is a flowchart showing an example of measurement of runout.

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

FIG. 12 is a diagram showing measurement of runout.

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

[Explanation of symbols]

 1 Runout measuring device 20 V pulley 22 Shaft 32, 33 Rail 34, 35 Slider 38, 39 V-grooved bearing

Claims (1)

[Claims] 1. A slider is mounted on a pair of bases so as to be movable back and forth, and V-shaped bearings are mounted and fixed on these sliders, respectively, and these V-shaped bearings are mounted on a rotating body to be measured. The shaft is passed over, and a runout detector is brought into contact with the rotating body to be measured. While rotating the rotating body to be measured, the core of the rotating body to be measured is rotated by the runout detector. A core shake measuring device characterized in that the shake is measured.