JPH0749954B2 - Non-contact inner diameter measuring tool - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of use) The present invention relates to a non-contact type inner diameter measuring tool used for measuring the inner diameter of a cylindrical object such as a cylinder. .

(Prior Art) Conventionally, in order to measure the inner diameter of a cylindrical body, a measuring tool such as a caliper or a gap gauge used by a worker by a handy operation is used. Each of these measuring tools is inserted into a cylindrical body, and a tentacle is pressed against the facing surface portion of the inner surface thereof, and the distance between the facing surface portions is directly read on a scale to measure the inner diameter of the cylindrical body.

(Problems to be solved by the invention) By the way, conventional measuring tools such as calipers and gap gauges are
All of them are contact-type measurement, in which the contactor is directly pressed against the inner surface of the inner surface of the cylindrical body, so the configuration is simple and easy to handle. It is quite difficult to bring the contactor into proper contact with the facing surface on a line orthogonal to the center line, and it may happen that the distance between the facing surfaces on a line deviated from the center line of the inner surface of the cylinder is measured. It is difficult to accurately measure the inner diameter (diameter) of all of them, and it is necessary to repeat the measurement at several points, so the work efficiency is poor and the accuracy is poor, and the inner surface of the cylindrical body during the measurement work I was worried that my tentacles would scratch me.

The present invention has been made in view of the above circumstances, and a first object thereof is to simply insert into a cylindrical object to be measured, such as a cylindrical body, and even if the object is inserted out of the center of the object to be measured, It is an object of the present invention to provide a non-contact type inner diameter measuring tool which can measure the inner diameter of an object to be measured easily and efficiently without contact and scratching.

A second object of the present invention is to simply insert the inner diameter of the object to be measured into the cylindrical object to be measured, and even if the object to be measured is inserted while being displaced or inclined from the center of the object to be measured. Another object of the present invention is to provide a non-contact type inner diameter measuring tool which is highly efficient and can be accurately measured in a non-contact manner without damaging it, which is advantageous for a handy operation.

[Constitution of device]

(Means for Solving the Problem and Its Action) The non-contact type inner diameter measuring tool of the first invention is a probe inserted into a cylindrical object to be measured in order to achieve the first object. The probe is provided with four distance sensors that are arranged in different directions by 90 degrees in the circumferential direction and that detect the distances to the inner surface of the object to be measured, which are respectively directed.

With the non-contact type inner diameter measuring tool having such a configuration, the probe is supported and inserted into the cylindrical object to be measured. At this time, the probe may be displaced from the center of the object to be measured. With the four distance sensors arranged in the probe in different directions by 90 degrees in the circumferential direction in the inserted state, the distance to the inner surface of the measured object pointed by each distance sensor is detected. With this, it is possible to know four points on the inner peripheral surface of the object to be measured, which are deviated by 90 degrees in the circumferential direction from the probe, and the respective distances from the center of the probe at the four points. Then, the inner diameter of the object to be measured is obtained by performing arithmetic processing with an arithmetic unit such as a personal computer according to a predetermined arithmetic expression.

A non-contact type inner diameter measuring tool of a second invention is, in order to achieve the second object, a probe to be inserted into a cylindrical object to be measured and a two-stage location in which a predetermined interval of this probe exists. In addition, both of the two steps are equal, and are provided with four distance sensors, which are arranged in different directions by 90 degrees in the circumferential direction and detect the distance to the inner surface of the DUT that each direction points. It is characterized by that.

In the case of the non-contact type inner diameter measuring tool having such a configuration, the probe is supported by a hand or the like and inserted into the cylindrical object to be measured by a handy operation or the like. At this time, the probe may be displaced or tilted from the center of the object to be measured. In the inserted state, in each of the two stages of the probe,
The distances to the inner surface of the object to be measured, which are pointed by the respective distance sensors, are detected by the four distance sensors arranged in different directions by 90 degrees. With this, first, the inclination angle of the probe is obtained from the difference between the distance detection values of the distance sensors pointing in the same direction at each of the two steps and the distance between the two steps, and the inclination of the probe is corrected, and the object to be measured is corrected. Since the four points on the circumference surface of the probe which are deviated by 90 degrees in the circumferential direction about the probe and the distances from the center of the probe at the four points are known, a predetermined formula is used based on them. The inner diameter of the object to be measured is obtained by performing arithmetic processing with an arithmetic unit such as a personal computer.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

First, in FIG. 1, 1 is a cylindrical object to be measured, and 2 is a non-contact type inner diameter measuring tool for measuring the inner diameter φ of the object to be measured 1. The non-contact type inner diameter measuring tool 2 includes an elongated pipe-shaped probe 3 that an operator can manually insert into the DUT 1 by holding the proximal end portion, a distal end of this probe 3 and a lateral side of the proximal end thereof. The distance sensors 4a, 4b, 4 are arranged at four positions in two steps from the position at which the predetermined distance L exists.
It is composed of c, 4d and 5a, 5b, 5c, 5d. Each of the distance sensors 4a to 2d and 5a to 5d is an optical or ultrasonic distance sensor that oscillates light or ultrasonic waves to detect the distance to the object to be measured.

The four distance sensors 4a, 4b, 4c, 4d at the first stage at the tip position of the probe 3 are arranged on the same plane perpendicular to the center line of the probe 3 by 90 degrees in the circumferential direction. It is arranged radially. Also, the four distance sensors 5a, 5b, 5c, 5d in the second stage, which are slightly closer to the base end side of the probe 3,
The probe 3 is radially arranged in the same plane as that of the first stage and on the same plane perpendicular to the center line of the probe 3 with their directions differing by 90 degrees in the circumferential direction.

Each of the distance sensors 4a to 4d of the non-contact type inner diameter measuring tool 2
Also, 5a to 5d are electrically connected to a computing unit 7 such as a personal computer via a wiring cord 6 led out through the inside of the probe 3. Then, the probe 3 is inserted into the cylindrical object to be measured 1 by handy operation or the like, and in that state, four distance sensors are arranged at the two stages of the probe 3 in different directions by 90 degrees in the circumferential direction. 4a-4d
And 5a to 5d, the distances to the inner surface of the DUT 1 detected by the respective distance sensors are detected, and the distance detection outputs from the distance sensors 4a to 4d and 5a to 5d are amplifiers and A / Ds. The DUT 1 is sent to the arithmetic circuit of the arithmetic unit 7 via a converter or the like and is subjected to arithmetic processing according to a predetermined arithmetic expression.
The inner diameter of is required.

The predetermined formula will be described. First, as shown in FIG. 2, the case where the probe 3 is inserted into the cylindrical object to be measured 1 in parallel will be described. In this case, the distance sensors 4a and 5a, 4b and 5b corresponding to each other at two stages are arranged. , 4c and 5c, and 4d and 5d output the same distance detection output, so it is sufficient to ignore the detection output from the distance sensor on one stage. Here, as shown in FIG. 3, four distance sensors detect the distance to the inner surface of the DUT 1 pointed by each distance sensor. As a result, points A, B, C, D on the inner peripheral surface of the DUT 1 in four directions deviated from the probe center S by 90 degrees in the circumferential direction.
And their respective distances a, B, C, D from the probe center S at the four points a,
Since b, c, and d are known, the inner diameter φ = 2r of the DUT 1 is calculated from the coordinates of these four points A, B, C, D by the following formula.

First, assuming that the probe center S is at the (p, q) coordinate point with respect to the center O of the non-measurement object 1 as shown in FIG. Is. The following relational expression is established from these coordinate points. That is, From these equations, ab ＝ r ² −q ² −p ² ＝ r ² − (p ² ＋ q ² ) cd ＝ r ² −p ² −q ² ＝ r ² − (p ² ＋ q ² ) ∴ab = cd is there.

on the other hand ^{4ab = 4r 2 -b 2 + 2ad} -a 2 -d 2 + 2cd-c 2 4r 2 = a 2 + b 2 + c 2 + d 2 Is required.

Next, as shown in FIG. 4, the case where the probe 3 is slantingly inserted into the DUT 1 having a cylindrical shape will be described. In this case, the distance sensors 4a and 5 arranged corresponding to each other at the two-stage positions will be described.
a, 4b and 5b, 4c and 5c, 4d and 5d output different distance detection outputs. With this, the distance detection values a ₁ and a ₂ , b ₁ and b ₂ , c ₁ and c ₂ ,
d ₁ and d ₂ (in the drawing, the distance detection value c _{1 in the} direction perpendicular to the paper surface
(c ₂ , d ₁ and d ₂ are not displayed) is obtained. Here, the difference _{a 1 -a 2, b 1 -b} 2, c 1 -c 2, d 1 -d 2 of the distance sensor mutual distance detection value directed to each the same direction of the two-stage position, the 2 The inclination angles θ ₁ and θ of the probe 3 are determined by the distance L between the steps.
₂ (in the drawing, the inclination angle θ _{2 in the} direction perpendicular to the paper surface is not displayed). Then, the inclination angles θ ₁ and θ _{2 are} corrected, and the distances a, b, c, d to the four inner surface parts orthogonal to the center line of the DUT 1 are shown as shown by the broken line in FIG. calculate. That is, a = a ₁ cos θ ₁ b = b ₁ cos θ ₁ where tan θ ₁ = (a ₂ −a ₁ ) / L c = c ₁ cos θ ₂ d = d ₁ cos θ ₂ where tan θ ₂ = (c ₂ −c ₁ ). As described above with reference to FIG. 3, the points A, B, C, D in the four directions deviated from the probe center S on the inner peripheral surface of the DUT 1 by 90 degrees in the circumferential direction. , The distances a, b, c, d from the probe center S of the four points A, B, C, D are known.
DUT 1 from the coordinates of points A, B, C and D using the same formula as above
It seems that the inner diameter φ = 2r is required.

The formula for obtaining the inner diameter φ of the DUT 1 described above can be proved geometrically as illustrated in FIG. That is, assuming that the probe 3 is inserted at the point S in the cylindrical object to be measured 2, two probes passing through the center O in the object to be measured 1 are parallel to the directions in which the four distance sensors point from the point S. Draw a diameter line. Then, as shown in the figure, when the four points A, B, C, D and the point P on the inner surface detected by each distance sensor are taken, The relational expression with Further, the distance detection values a, b, c, d of each distance sensor are a = ▲ ▼, b = ▲ ▼, c = ▲ ▼, d = ▲ ▼, so if the above ▲ ▼ and ▲ ▼ are rewritten, Where ∠ACD = ∠ABD (circumferential angle of arc AD) ∴ △ SAC∽ △ SDB Becomes

In addition, in the above-described embodiment, four distance sensors are provided at two stages of the probe 3 so that it can be dealt with even if it is inserted obliquely into the DUT 1 by handy operation or the like. Although it is not shown in the figure, if you can always insert it into the DUT without tilting it with a mechanical device such as a robot,
It is also possible to provide four distance sensors only at one stage.

〔The invention's effect〕

The non-contact type inner diameter measuring tool of the present invention is arranged such that the probe inserted into the cylindrical object to be measured as described above and the probe are arranged so as to face each other by 90 degrees in the circumferential direction, and each of them is oriented. Since the structure is provided with four distance sensors that detect the distance to the inner surface of the object to be measured, it can be inserted only into the cylindrical object to be measured, and can be inserted from the center into the object to be measured. Even in this case, the inner diameter of the object to be measured can be measured easily and efficiently, and in a non-contact manner, and without any fear of damage, it becomes very simple.

The non-contact type inner diameter measuring tool of the present invention has a probe to be inserted into a cylindrical object to be measured as described above, and two step portions at a predetermined interval of this probe, both of which are equal to each other. A cylindrical body or the like, which is provided with four distance sensors that are arranged in different directions by 90 degrees in the circumferential direction and that detect the distance to the inner surface of the measured object, which is directed respectively. Just by inserting into the object to be measured, and even if it is inserted from the center of the object to be measured or tilted, the inner diameter of the object to be measured can be easily and efficiently and non-contactly and accurately It is very convenient and practical for handy operation that can be measured.

[Brief description of drawings]

FIG. 1 is a partially blocked perspective view showing an embodiment of the present invention, FIG. 2 is a schematic view of a distance detection state when a probe is inserted straight into an object to be measured, and FIG. 3 is the same state. 4 is a plan view of FIG. 4, FIG. 4 is a schematic view of a distance detection state when a probe is obliquely inserted into an object to be measured, and FIG. 5 is an explanatory view for geometrically proving the formula of the diameter. 1 ... Object to be measured, 2 ... Non-contact type inner diameter measuring tool, 3 ...
Probes, 4a, 4b, 4c, 4d, 5a, 5b, 5c, 5d ... Distance sensors.

Claims (2)

[Claims] 1. A probe to be inserted into a cylindrical object to be measured, and a distance to the inner surface of the object to be measured, which is arranged on the probe in different directions by 90 degrees in the circumferential direction and is directed respectively. A non-contact type inner diameter measuring tool comprising four distance sensors for detecting the. 2. A probe to be inserted into a cylindrical object to be measured, and two steps at a predetermined interval in the longitudinal direction of the probe, both steps being equal to each other in the circumferential direction.
A non-contact type inner diameter measurement tool, which is provided with four distance sensors arranged in different directions by 90 degrees and each detecting a distance to the inner surface of the measured object.