JP3428093B2 - Alignment measurement device - Google Patents

Description

BACKGROUND OF THE INVENTION [0001] FIELD OF THE INVENTION This invention runout measuring the runout of the rotating body such as a V-pulley which is used in various electronic apparatuses
The present invention relates to a measuring device , and particularly to accurately measure a run-out and a step generated due to a die abutment error. 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. . [0003] The runout occurs when the center (axis) of the formed V-pulley deviates from a design value. When the runout is not within an allowable range (usually within a range of about ± 10 μm), it is unreasonable. It will be a good product. In order to manufacture a non-defective product, it is necessary to correct (fine-adjust) the mold so that the misalignment falls within an allowable range. Prior to such mold adjustment, the centering measurement is performed. FIG. 9 shows an example of a conventional eccentricity measuring device 10. Reference numeral 12 denotes a measurement base on which a measurement table 14 is mounted, and on the upper surface of which is fixed a shaft mounting table 16 having a shaft insertion hole 17 formed therein. 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.
The V-pulley 20 is rotated while the tip portion 25 of 4 is lightly abutted (see FIG. 10). 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 q-q 'fluctuates according to the rotational position of the V-pulley 20, as shown by an arrow a in FIG. Is detected by the detector 24. Detector 24
The pass / fail is determined based on the detection data (measurement data) detected in (1). FIG. 11 shows the calculated measurement data as an angle in the circumferential direction on the horizontal axis, and FIG. 12 shows the calculated data without expanding the rotation angle. Become. Referring to FIG. 11 or FIG. 12, each correction amount of a step and a run-out caused by abutment of the mold is determined by empirical rules while taking into account the respective correction amounts, and based on the correction amount, the impact of the mold (specifically, the slide core) is determined. The mating position and the planting position of a core pin (not shown) for forming the shaft hole of the V pulley 20 are corrected. To correct (correct) the planting position of the core pin, the nest (not shown) may be made again. For this reason, the correction amount of the step and the center deviation is shown in FIG.
Alternatively, since it is only obtained from the graph of FIG. 12, it is difficult to correct the misalignment including the step accurately, and the desired correction can be performed only after performing correction several times. Therefore, there is a drawback that the correction accuracy is low and the correction time is long. Therefore, the present invention has been made to solve such a conventional problem, and proposes an alignment deviation measuring apparatus capable of achieving high correction accuracy and shortening the correction time. [0011] In order to solve the above-mentioned problems, according to the present invention, a measured object formed by a mold is used.
In the apparatus for measuring the run-out of the rotating body,
Abuts on the rotating body and changes due to the rotational position of the rotating body to be measured.
Detecting means for detecting a motion with respect to the circumferential direction of the measuring rotary member, set of m measurement points, said detecting means
In among the measurement data at each measurement point obtained, close
The measurement data position where the measurement data difference is large between the measurement points is extracted, and the position with the step
Is detected, and the abutment of the mold is determined from the size of the step at the abutment end face.
With obtaining the level difference correction amount in position, n from which the reference axis the abutting end face of the upper Symbol m pieces of the measurement data
Calculating means for calculating the center of gravity of ((360 ° / n °) +2) from the measured data for each °, and calculating the amount of correction for centering based on the calculated center of gravity; and displaying the calculated result.
And display means . When the processing program shown in FIG. 1 is started, V
First, measurement data from the temporary reference point S on the circumference of the pulley 20 to a total of m points (m = 360) around the circumference is obtained. A step is obtained by extracting large measurement data, and a step correction amount is calculated from the step (steps 81 and 82). When the position of the step is determined, the position of the determined step is set as a reference axis, and a new reference point t to n is set.
° (n = 30), the measurement data is extracted, and ((3
(60 ° / n °) +2) A rectangular center of gravity G is calculated (steps 83 to 85). When the measurement data is extracted every 30 °, the center of gravity G (xG, yG) of the dodecagon is obtained as a whole. Since molding is usually eccentric in many cases, ± Δx, ± Δx, ±
By giving each correction value of Δy, a new center of gravity G ′ (xG ′, y
G ′) is calculated (step 86). 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 measurement data. The difference (ΔxG, ΔyG) between the calculated center of gravity GO and the true axis becomes the centering correction amount (steps 87 and 88). [0015] The abutment position of the mold is corrected based on the step correction amount, and a new nest for the core pin is formed or the slide core is re-formed after the slide core is moved based on the misalignment correction amount. The result is accurate. A description will now be given, with reference to the accompanying drawings, of an apparatus for measuring a run-out according to the present invention, which is applied to the run-out measurement of the V-pulley described above. The misalignment measuring device according to the present invention compensates for misalignment.
Because when positive for it is necessary to accurately measure the runout, in the core shake measurement Ru Tei is devised so as not to affect by the surface vibration. First, a description will be given of this deviation. When the V-pulley is formed by injection molding, depending on the abutting state of the mold as described above, in addition to centering, there may be a run-out. Fig. 9 shows the V-pulley 20
When the measurement is performed by the misalignment measuring device 1 shown in FIG. For example, when there is a run-out in the molded product, and this is formed with the axis inclined by 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 portion p by 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. The deviation measuring apparatus 1 shown in FIG. 3 is a measuring apparatus capable of avoiding the influence of the deviation. FIG. 3 is a plan view showing an example of the eccentricity measuring apparatus 1 according to the present invention, which is shown in FIG. 4 showing a top view thereof and FIG. 5 showing a partially cut-away side view, respectively. 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 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 holding plates 32a, 32b, 33a, 33b, respectively, using well-known means (not shown) such as screws (see FIG. 3). Sliders 34 and 35 that slide using the rails 32 and 33 as guides are attached. As shown in FIG. 5, the sliders 34 and 35 have inverted U-shaped cross sections.
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. An auxiliary member 3 is provided on the upper surfaces of the sliders 34 and 35.
6 and 37, bearings 38 and 39 having V-shaped grooves as shown in FIG. 5 are attached to the mutually opposing side surfaces of the auxiliary members 36 and 37. 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. 3, a drive motor 40 is fixed to one of the bases 30, and a shaft pulley 42 is mounted on a rotating 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 by a holding plate 46 in order to keep the facing 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 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 is mounted on the 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 in contact with the tip 25 of a detector 24 as shown in FIG.
By rotating 0 at a predetermined speed, the center deviation of the V pulley 20 is measured. During this misalignment measurement, the V pulley 20
When there is a run-out, the tip 25 of the detector 24 acts 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. Bearings 38, 3 on which the shaft 22 is mounted
The belt 9 is axially substantially integrated with the belt 47 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. Slider 34,
Since the slider 35 is free in the axial direction, the sliders 34, 35
Slides 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 faces the bottom p of the V-shaped groove 21 and is at a position where the component force becomes zero when reaching the bottom p, whereby 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 slide 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 displacement measurement according to the present invention 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. 6, cavities 50a and 51a for the V pulley 20 are formed in a pair of dies (actually, slide cores) 50 and 51, respectively, and they are abutted as shown in the figure. When they are in perfect abutment, both molds 50,
There is no step 54 (FIG. 7) between 51. However, in most cases, the molds 50 and 51 cannot be abutted with the step 54 being zero (ΔL = 0), so that the mold 50 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 the measurement of the deviation, the 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. 12), and an axis (O-
The measurement of the center deviation is started from O ′). An example of the measurement results at that time is shown in FIGS. 11 and 12, respectively. FIG.
FIG. 12 is an expanded view of measurement data for each representative angle (30 ° in the figure), and FIG. 12 also shows typical measurement data on the basis of a curve Lb in which the eccentricity is zero. is there. Curve La is the alignment 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. 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 the steps as shown in FIG.
A line xx connecting t and u is used as a reference line (abutting end face). (ΔL1 + ΔL2) / 2 is the abutment position correction amount of the dies 50 and 51 with respect to the sizes ΔL1 and ΔL2 of the step 54. When the step is as shown in FIG.
0 in the s direction by (ΔL1 + ΔL2) / 2,
The other mold 51 also has the same amount in the r direction (= (ΔL1 + ΔL2)
/ 2) to correct. More specifically, the correction is made by cutting or overlaying the contact surfaces between the slide cores 50 and 51 and the slider (not shown). At the same time as the calculation of the step, the correction amount of the center deviation is calculated using the measurement data described above. Although the run-out can be measured using the V-pulley 20 formed after correcting the level difference, the former is exemplified in this example. In order to measure the deviation, for example, as shown in FIG. 12, measurement data corresponding to every 30 ° (= n °) is extracted from the reference line xx, and a step difference is added to the extracted 12 measurement data. The correction amount is taken into account, and the center of gravity G (xG, yG) determined by the measurement data in which the step correction amount is taken into account is calculated, and the difference between the calculated center of gravity G and the original axis center is used as the centering correction amount. You. 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 reshaping the nest. FIG. 2 shows an example of a circuit system of the measuring apparatus 1 for realizing such a correction method.
The measurement data detected by the detector 24 is
Is supplied to an A / D converter 62 to be converted into a digital signal of a predetermined number of bits. The converted measurement data is also supplied to a CPU 63, and a centering measurement program including a step measurement provided here is used. Then, the calculation of the step correction amount, the calculation of the core deviation correction amount, and the like are automatically executed. 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. Reference numeral 64 denotes the measured data shown in FIG. 11 or FIG.
And a display unit (such as a CRT or a liquid crystal element) for displaying the calculation results, and a printer 65 for printing such data. The above-mentioned 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 (auxiliary nest). used. FIG. 1 is an example of a flowchart showing a processing procedure for calculating a level difference correction amount and a center deviation correction amount according to the present invention. When the above-described processing program is started,
First, measurement data from the temporary reference point OO 'shown in FIG. 12 to m points (m = 360) is obtained (step 81), and a step determination process and a step correction amount are calculated from these m points of measurement data. Is performed (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), ((360 ° / n °) +
2) A rectangular center of gravity G is calculated (step 85). 30
When the measurement data is extracted for each degree, the center of gravity G (xG, yG) of the dodecagon is determined as a whole. The center of gravity G of the polygon is calculated by a well-known mathematical method. In many cases, the eccentricity is usually caused in the molding of the mold. Therefore, ± Δx, ±
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 misalignment correction (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 was applied to the run-out measurement of 0, it can be easily understood that the rotating body to be measured can be applied to other than pulleys used in tape recorders and the like, including flat pulleys without V-shaped grooves. As described above, in the misalignment measuring apparatus according to the present invention, the rotation measuring object is brought into contact with the rotating body to be measured, and
Detecting means for detecting fluctuations due to the rotational position of the rolling member, and m measuring points are set in the circumferential direction of the rotating body to be measured , and at each measuring point obtained by the detecting means , of the measurement data, the measurement data between the measurement point adjacent
Extract the measurement data position where the difference is large, and
, The abutting end face is detected, and the step of this abutting end face is detected.
Of the level difference at the abutment position of the mold from the size of the mold
With that, the abutting end face of the upper Symbol m pieces of measurement data from the measurement data of each than this n ° as a reference axis ((3
(60 ° / n °) +2) calculating means for calculating the center of gravity of the square and calculating the amount of misalignment correction based on the calculated center of gravity ;
Display means for displaying the result of the calculation . According to this, the correction amount can be calculated by accurately measuring the misalignment including the step without relying on intuition or empirical rules, so that the molding accuracy can be remarkably improved. Further, 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 not affected by the run-out. Can be corrected. Therefore, the present invention is very suitable for application to correction of centering of a pulley or other rotating body of a tape recorder requiring relatively strict molding accuracy.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flowchart showing an example of a method for correcting misalignment according to the present invention. FIG. 2 is a system diagram showing an example of a circuit system of a displacement measuring apparatus to which the present invention is applied. FIG. 3 is a plan view illustrating an example of a misalignment measuring device. FIG. 4 is a top view of FIG. 3; FIG. 5 is a side view in which a part of FIG. 3 is sectioned. FIG. 6 is a view showing an abutting state without a step. FIG. 7 is a diagram showing an abutment state with a step. FIG. 8 is a diagram showing an example of measurement data near a step. FIG. 9 is an explanatory diagram of a conventional misalignment measuring device. FIG. 10 is a diagram showing a deviation measurement. FIG. 11 is an expanded view of an example of misalignment measurement data. FIG. 12 is a diagram showing unaligned measurement data without developing it. FIG. 13 is a diagram showing an example of measurement of misalignment in a state including surface deviation. [Description of Signs] 1 Alignment measurement device 20 V pulley 22 Shaft 32, 33 Rail 34, 35 Slider 38, 39 V-groove bearing

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-69453 (JP, A) JP-A-2-105007 (JP, A) JP-A-62-222115 (JP, A) 418 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B29C 45/14 B29C 33/30

Claims (1)

(57) [Claims] [Claim 1] A rotating body to be measured molded by a mold.
In the apparatus for measuring misalignment , the rotating body for measurement is brought into contact with the rotating body for measurement,
Detecting means for detecting variation due translocation, to the circumferential direction of the measuring rotary member, set of m points of measurement, among the measurement data at each measurement point obtained by the detection means, the proximity difference between the measured data between the measurement points is to extract a large measurement data position, a level difference
By detecting the position, the abutting end face is detected, and the
From the size of the step, determine the step correction amount at the abutment position of the mold.
With finding, the abutting end face of the upper Symbol m pieces of measurement data from the measurement data of each than this n ° as a reference axis ((360 ° / n
°) +2) calculates the center of gravity of the square, and calculating means for obtaining a core shake correction amount calculated center of gravity as a reference, the core shake measuring apparatus characterized by having a display means for displaying the result of the calculation .