JPS63182510A - Easy method and device for measuring roundness of shaft body center hole - Google Patents

Abstract

PURPOSE:To easily and quantitatively measure the roundness of a shaft body center hole by rotating a shaft body product around a temporary center, measuring the distance from the temporary center to a part to be measured at the inner periphery of the center hole, and finding the roundness from the quantity of variation in obtained measured value. CONSTITUTION:When the shaft body product 17 which is supported in a support center 18 at one end and by a center main body 12 at the other end is rotated as shown by an arrow A, a measuring element 13 moves away from or to the main body 12 according to the internal-diameter shape of the center hole 17a and the quantity of its movement is detected by a detector 14 as the quantity of variation with a basic radius. The detection data is sent to a measurement amplifier 15 and the radius size from the temporary center O is calculated with a previously approved reference radius and the sent data. Then the deviation values of a maximum and a minimum radius Rmax and Rmin are computed an the obtained deviation values are displayed on the display device of the measurement amplifier 15 as substitute values of the roundness. An error in the accuracy of the roundness of the center hole at the time of the inspection of the product has no variance because it is decided whether or not the error is within a permissible range, so the quality is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention determines the roundness of a center hole, which is a processing standard for a shaft product, by determining a temporary center by supporting both ends of the shaft product, and then determining the circularity of the center hole, which is a processing standard for shaft products. The present invention relates to a simple method for measuring the roundness of a center hole of a shaft object, in which the distance to a measurement site, that is, the amount of change in the radius dimension of the center hole, is measured as a substitute value for roundness, and a measuring device that performs this measurement method.

Conventional technology The roundness of a center hole, which is a processing standard for shaft products, has conventionally been measured by measuring the roundness of an angular center hole 1a formed in a shaft product 1, as shown in FIG. 4, for example. For this purpose, a ball gauge 2 is used, and a conical gauge 4 is used for the spherical center hole 3a of the shaft product 3 as shown in FIG. It has been common practice to apply a pigment such as red and rotate it within each of the center holes 1a and 3a to check for contact and make measurements.

Problems to be Solved by the Invention However, in the conventional method for measuring the roundness of a center hole described above, the pigment applied to the outer circumferential surface of the ball gauge or conical gauge rubs against the inner circumferential surface of the center hole. The roundness of the center hole can be checked by observing the state of the part where the pigment on the gauge side is lost or the state of the pigment adhering to the inner peripheral surface of the center hole. Because of the measurement, skill is required for the measurement work, and there are problems in that the measured value of roundness cannot be obtained quantitatively.

There are also devices that quantitatively measure roundness using the radius method, but most of these devices measure the roundness of the outer shape of the product, so they measure the roundness of the center hole of shaft products. There are also devices that use a tripod gauge to measure the circularity of a hole using the three-point method, but these devices have problems such as being time-consuming and expensive. was there.

This invention was made in view of the above-mentioned problems, and it is possible to easily measure the roundness of the center hole of a shaft product in a short time by quantitatively measuring the roundness of the center hole of the shaft product based on the deviation value of the radius dimension from the temporary center. The purpose of this paper is to provide a simple method for measuring the circularity of holes and an inexpensive measuring device for performing this method.

Means for Solving the Problems As a means for solving the above-mentioned problems, the measuring method of the first invention defines a temporary center by supporting both ends of a shaft product having a center hole at the center. The shaft product is rotated around , the distance from the temporary center to the measured part on the inner periphery of the center hole is measured, and the roundness is determined from the amount of change in the obtained measured value.

Further, the measuring device of the second invention has a conical measuring center body that engages with and supports a center hole formed at the other end of a shaft product that is an object to be measured whose one end is supported at the center. and a slender rod-shaped measurement device that is arranged parallel to the generatrix of the measurement center body at a slight distance from the measurement center body, and whose base end is supported so that it can move in parallel and move toward and away from the measurement center body. a sensor that is mounted perpendicularly to the probe to detect the amount of displacement of the probe, and a measurement device that calculates a deviation value based on the amount of displacement detected by the detector and displays the calculation result. It is characterized by being equipped with an amplifier.

Function This simple method for measuring the roundness of the center hole of a shaft product determines the temporary center by supporting both ends of the shaft product at the center, measures the amount of change in the radius dimension from this temporary center, and calculates the maximum and minimum values. This is a method of finding a deviation value from the value and using this value as a substitute value for roundness.

This is because the conventional method for measuring roundness using the radius method rotates the object to be measured around a temporary center O at a constant rotation angle θ. =360'
Rotate by /n (n is an integer greater than 4) to measure the deflection of the micrometer Δr H (i=1.2......n)
If you read Δri−ao+a1Cos(θ.
)+a2cos(2θ.10β1)10... howl.

Here a. is the value a1cos(θ
. 1β1) is the eccentricity of the temporary center. Therefore, the deviation Δ from a perfect circle is Δ−ΔrH−(ao+a1cos(θ.

+β1)), and the circularity of the radius method is -Δm
In contrast, the simple roundness measurement method of the present invention calculates the deviation value (maximum In this method, the roundness can be calculated simply and quantitatively using this deviation value.

In addition, this simple roundness measuring device has one end supported at the center, and the measurement center body and measuring tip of this device are integrally engaged with the center hole of the other end of the shaft product to determine the temporary center. When the shaft product is rotated, the probe moves in parallel as the distance from the temporary center to the inner peripheral surface of the center hole changes, and the detector detects the amount of movement of the probe, and the detected amount The measured data is sent to the measurement amplifier, and the deviation value calculated by the measurement amplifier is displayed as a substitute value for roundness.

EXAMPLES The present invention will be explained below with reference to FIGS. 1 to 3.

1 and 2 are explanatory diagrams showing the principle of the simple roundness measuring method according to the present invention, and FIG. 3 is an illustration of a simple roundness measuring device for measuring roundness by the measuring method according to the present invention. It is an explanatory view showing an example.

In FIG. 3, a measuring device 11 for simply measuring the roundness of a center hole of a shaft product includes a base block 11a, a 6
0' bell-shaped measuring center body 12; and a pin-shaped measuring center body 12 with a circular cross section arranged parallel to the generatrix of the conical measuring center body 12 at a position close to this measuring center body 12. a measuring element 13, a detection device 14 for detecting the amount of movement of the measuring element 13, a measuring amplifier 15 having a calculation function, and a support center coaxially disposed opposite the measuring center main body 12. (not shown).

The measuring center main body 12 is attached to the base block 11a via a bracket part 11b so that its conical top is at the most extreme end of the apparatus. Further, the tip of the measuring element 13 is disposed at approximately the same position as the conical top of the measuring center body 12, and its base end is attached to the base block 11a side via a parallel leaf spring 16, so that measurement can be carried out by The center main body 12 is movably arranged parallel to the generatrix of the main body 12. Further, the detector 14
is attached to the bracket part 11b so as to be perpendicular to the moving direction of the measuring element 13, and the detecting part 14a at the tip thereof is brought into contact with the side surface of the measuring element 13.
A measurement amplifier 16 is connected to this detector 14 via a lead wire.
The measurement amplifier 16 calculates a deviation value based on the detection data from the detector 14 and displays the calculation result.

Next, a measuring method of the present invention using the measuring device 11 configured as described above will be explained based on FIGS. 1 and 2.

The shaft product 17 whose center hole is to be measured for roundness has center holes 17a and 17b at both ends on its center line C.
are formed, the support center 18 is engaged with one center hole 17a, and the other center hole 17a is engaged with the support center 18.
The measuring center main body 12 and the measuring tip 13 are inserted into the center and supported by both centers 12 and 18 to form a temporary center O.
It is centered and set. At this time, the measuring head 1
3 is arranged so as to be in contact with the measurement reference part (generally called the gauge diameter) on the inner peripheral surface of the center hole 17a, and to move according to the change in the distance from the temporary center O to the measurement reference part. The detector 14 is arranged to detect the amount of movement of the probe 13 as a change amount with respect to a preset reference radius (see FIG. 1).

Next, when the shaft product 17, which is supported at one end by the support center 18 and the other end by the measurement center main body 12, is rotated in the six directions of arrows in FIG. 2, the inner diameter shape of the center hole 17a (in FIG. (indicated by a solid line), the measuring stylus 13 moves in a direction away from or toward the measuring center main body 12, and the amount of movement is detected by the detector 14 as a change amount with respect to the reference radius. The measured data is sent to the measurement amplifier 15, and the measurement amplifier 15 determines the radius dimension from the temporary center O based on the preset standard radius dimension and the sent data, and first calculates the maximum radius Rmax and the minimum radius Rmir+. The difference between the maximum radius R+nax and the minimum radius Rr+in, that is, the deviation value, is calculated, and the deviation value obtained by the calculation is displayed on the display device of the measurement amplifier 15 as a substitute value for roundness.

Then, as described above, the center hole 17a of the shaft product 17 is
Since the roundness of the center hole can be easily and quantitatively measured, it can be used to determine whether the accuracy error of the center hole roundness is within or outside the allowable range during product inspection of shaft products. Variations are eliminated and quality can be improved.

As described in detail, the measuring method according to the present invention determines a temporary center by supporting both ends of a shaft product having a center hole at the center, and rotates the shaft product around this temporary center to temporarily measure the shaft product. The distance from the center to the measured part on the inner periphery of the center hole is measured, and the roundness is determined from the amount of change in the measured value, so the roundness of the center hole of the shaft object can be easily and quantitatively measured. have an effect.

Further, the measuring device according to the present invention has a conical measuring center that engages with and supports a center hole formed at the other end of a shaft product, which is an object to be measured and whose one end is supported at the center. a slender rod-shaped body which is arranged parallel to the generatrix of the measuring center body at a slight distance from the measuring center body, and whose base end is supported so as to be able to move in parallel to move toward and away from the measuring center body; A measuring point, a detector attached perpendicularly to the measuring point to detect the displacement of the measuring point, and calculating a deviation value based on the displacement detected by the detector and displaying the calculation result. Since it is equipped with a measuring amplifier, it has excellent advantages such as a simple structure, easy operation for measuring roundness, quick measurement, and low cost of the device.

[Brief Description of the Drawings] Figures 1 and 2 are explanatory diagrams showing the principle of the simple roundness measurement method according to the present invention, and Figure 3 is a diagram showing the principle of the roundness measurement method according to the present invention. An explanatory diagram showing an example of a simple roundness measuring device, FIGS. 4 and 5 show an example of a conventional roundness measuring method, and FIG. 4 is an explanatory diagram showing a measuring method using a ball gauge. FIG. 5 is an explanatory diagram showing a measurement method using a conical gauge. 11... Measuring device, 11a... Base block, 1
1b...Bracket part, 12...Measurement center body, 13...Measure head, 14...Detector, 1
4a...detection section, 15...measurement amplifier, 16.
...Parallel leaf spring, 17...Shaft product, 17a, 1
7b...Center hole, 18...Support center,
O...Temporary center, Rmax...Maximum radius, Rmin
...Minimum radius.

Claims (2)

[Claims] (1) Determine a temporary center by supporting both ends of the shaft product with a center hole at the center, and rotate the shaft product around this temporary center to reach the measurement area from the temporary center to the inner circumference of the center hole. A simple method for measuring the roundness of a center hole of a shaft object, which is characterized in that the distance is measured and the roundness is determined from the amount of change in the obtained measured value. (2) A conical measuring center body that engages with and supports a center hole formed in the other end of the shaft product, which is an object to be measured with one end supported at the center, and this measuring center. A slender rod-shaped measuring element that is arranged slightly apart from the main body and parallel to the generatrix of the measuring center main body, and whose base end is supported so that it can move in parallel to approach and move away from the measuring center main body; A detector is installed perpendicularly to the sensor and detects the amount of displacement of the probe, and a measurement amplifier that calculates a deviation value based on the amount of displacement detected by the detector and displays the calculation result. A simple device for measuring the roundness of the center hole of a shaft object.