JPS6244614A - Method and instrument for measuring squareness - Google Patents

Abstract

PURPOSE:To measure squareness with high accuracy with simple constitution by forming measuring beams of light using a reflector. CONSTITUTION:The title method is a measuring method to measure squareness of a central axial line 4 with a plane part 5 of an object 10 to be measured having a reference hole 3 and the orthogonal plane part 5 to the central axial line 4 of the hole. The plural lights of the 1st beams of light 24c-27c which make a straight advance in the opposite directions mutually on the same optical path and the plural lights of the measuring beam lights consisting of the 2nd beams of light 25d-27d are projected in parallel mutually and one measuring beams of light among these measuring beams of light 25c-27c, for instance, 26c is made the reference measuring light and the object 10 to be measured is positioned at the position where the reference measuring light is passed through the reference hole 3. Then, the squareness is obtained by comparing the optical paths between the reflected light of the measuring light beam 26c at the plane part 5 of the object 10 to be measured and the measuring light beam 26c.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a squareness measuring method and apparatus suitable for measuring the squareness of a member such as a hollow tube with a flange attached. Background and problems] A part with a shape of a tube body (1) having seven lunges (2), (2) at both ends, as shown in Figure 3, has been widely used in various industries. ing. For example, there are various precision applications ranging from fluid pipes to electro-optical components for space equipment. Such parts generally have their tubes (1
) with respect to the center axis (4) of the reference hole (3) of the flange (
The accuracy of the perpendicularity of the flat part (end face) (5) in 2) is important. To measure this squareness, as shown in Figure 4, the flat part (5) of the seven flange (2) to be measured is placed against the reference surface (7) of the jig (6) and fixed. The head (9) of the probe 1, for example, an electric micrometer, is mounted on a table (8) movable in a direction perpendicular to the probe (7), and the table (8) is moved in the longitudinal direction of the tube body (1). 9) is the tube body (
1) The amount of movement in and out δ(x) along the outer wall was measured to find the perpendicularity. According to such a method, the measuring point is the outer shape of the tube body (1), and it cannot necessarily be said that the central axis (4) is being measured, so the accuracy is low. Furthermore, if a large number of heat dissipation fins are attached to the outer wall of the tube body (1), measurement is impossible at all.Furthermore, since measurements are taken by directly contacting the outer wall, there are inconveniences such as scratches on the outer wall. Purpose of the Invention The present invention was made in order to eliminate the above-mentioned disadvantages, and an object of the present invention is to provide a method for measuring squareness that is highly accurate, non-contact, and easy to measure, and an apparatus for carrying out the method. do.

[Importance of invention]

The method of the present invention is a method for measuring the perpendicularity of the flat part to the central axis of an object to be measured, which has a reference hole and a flat part substantially perpendicular to the central axis of the reference hole. A plurality of measurement beams consisting of a first beam and a second beam directed in opposite directions are projected in parallel to each other, and a part of these measurement beams is used as the reference measurement light, and this is the reference measurement light described above. Position the object to be measured so that it passes through the hole so that its central axis is parallel to the measurement beam, and at this time, the optical path as a reflection of the measurement beam distributed by the flat surface and the optical path when it is not blocked. a projection optical system for projecting the first beam, a reflector for converting the first beam into the second beam by reflection to form the measurement beam, and a beam splitter. It consists of a detection optical system that directs the measurement beam light out of the optical path and receives it by the detection object, and a holding table that positions and holds the object to be measured so that the entire luminous flux of the reference measurement light passes through the reference hole. This is a perpendicularity measurement device that detects the perpendicularity by comparing the optical path of a measurement beam that is blocked by a flat surface of an object with a detection object between the optical path when the measurement beam is not emitted and the optical path when the measurement beam is reflected.

[Embodiments of the invention]

Hereinafter, details of the method and apparatus of the present invention will be explained using examples. First, one inventive device will be explained, and its operation and inventive method will be described.

In Figures 1 and 2, this device is a projection optical system αυ
, a reflector α2, a detection optical system α, an arithmetic unit α, and a holding table σ. The light projection optical system συ uses a laser oscillator 21) and the laser beam oscillated from it into three beams (22a), (22b),
For example, a diffraction grating is used to divide these beams (22a), (22b), and (22c) into a first beam (25) whose optical axes i, ca, and (27) are parallel.
a), (26a), and (27a). Note that the first light beam (26a) serves as a reference measurement light during positioning, which will be described later. The reflector (1B is composed of a plane reflection mirror, whose reflection plane is set perpendicular to the optical axis (E), @, (5), and the first beam light (25a), (26a), (27a) to form second beams (25b), (26b), and (27b) having the same optical path but opposite directions;
and the second beam light (25a), (25b) and the first and second beam light (26a), (26b) and the first
and a second beam of light (27a).

(27b) and three mutually parallel measurement beams (2
5c), (26c), and (27c) are constructed.

The measurement beam light (26c) is the reference measurement light described above. The detection optical system α■ is the reflector α near the lens (to)
Placed on the 2 side... - It is composed of the harp beam splitter Gυ and the detection object C2, and the harp beam splitter 6
1) is provided at an angle of 45 degrees with respect to the optical path (to), and the second beam light (25b), (26t)), (
Half of 27b) is reflected at right angles to optical path (25) external pressure detection light (25d), (26d), (27d)
The detection object C (3) is derived. The detection object C3 has a flat light-receiving surface (to), and photoelectric conversion elements are arranged in a matrix on this surface, and the detected light is The light receiving positions of (25d), (26d), and (27d) are sent out as electrical signals.The arithmetic unit αD has a built-in microconbeater and calculates changes in the light receiving positions based on electrical signals from the detection body. .

The holding stand α9 is provided between the beam splitter C31) and the reflector A, and includes a one-turn table C3 and a Y-table mounted on the table C3, which is movable in the Y direction.
It consists of a table (3?) and V blocks (to) and (to) that are provided on this Y table θη and whose position can be adjusted in the height direction (direction perpendicular to the paper screen).
is measured by placing the tube body (1) on the V block (toward).

The present apparatus is constructed as described above, and its function and method of the present invention will be described below. The laser light emitted from the laser sighting device CD is divided into three first beams (25a), (26a) (2
7a) Tona #) Go to the left in Figure 1 and take the flat reflector (12a)
) and reflected by the second beam light (25b), (2
6b), (27b '1 and the first beam light (2
5a), (26;'I), and (27a) travel in the opposite direction on the same optical paths (c), (to), and (l). This first beam light (25a), (26a), (27a
) and a second beam of light (25b).

(26b), (27b) and measurement beam light (25c)
> , (26c), (27c) are formed, and the measurement beam light (26c) is set as the reference measurement light. These measurement beam lights (25c), (2Gc), (27c
) is partially reflected by the No.-7 beam splitter Gυ, and the detection light (25d), (26d), (27d
) as a light emitting optical system (111), and the detection object 02
The light is projected onto the light-receiving section (to).

Each projection position (XI, XO, X2) is sent as an electrical signal from the photoelectric conversion element to a calculation device, and the position is calculated and displayed. Next, place the object to be measured α0 on the V block (top), and position the reference measurement light (26C) so that its entire luminous flux passes through the reference hole (3) by rotating, vertically, and adjusting the Y-direction end. In this state, the reference measurement light (26
In c), the detection object C3 is placed at the same position as when there is no object to be measured α1.
aK Project. Now, the flat part (5) of the object to be measured αQ blocks the measurement beam lights (25c) and (27c), and they are reflected here and are derived as detection lights (25d) and (27d). and their positions (Xl').

Xo, X2) are calculated and displayed by the calculation device α4 in the same manner as described above. At this time, the central reference measurement light (26
The position fiX'o on the detection object C in C) coincides with the position Xo if the direction of the laser beam device does not change. If the flat part (5) of the object to be measured [α] is completely perpendicular to the central axis (4), the two detection lights (25d) and (27d) will not change and the positions R(X'l), ( X'2) is the position (Xl), (
X2) respectively. However, if the angle is not completely perpendicular, the measurement beam light (25
c), (27c) is on the optical axis 12, and is offset from the @ position (Xl) C position #QCs') F, position t (X2)
To tll (Xz')! : It will be displaced.

For example, if the 7 flange (2) and the tube body (1) are not at right angles, that is, if the plane part (5) and the central axis (4) are at right angles and are (-10) rad, then the direction of the reflected light is is 2
θ changes, and the light receiving surface (change in projection position on the image Δ=X' −
X=(L t +L2 ) tan2θJF2 (Ll
+L2) θ. However, X is the projection position of the detection object's land when the plane part (5) and the central axis (4) are at right angles, and X' is the end face of the LI flange (2) at the projection position when (-+θ) rad. The distance from 41 to the intersection point (41) where the central axis line (4) intersects with the hub beam splitter 61), L
2 is the distance from the intersection point to the light receiving surface Q3. -For example, the light of the object to be detected! If the conversion element is a line sensor with a pitch of 10 μm and L1+L2 is 10cIrL, then θ=5X10 r if the fluctuation of the laser beam (c) is ignored.
ad and extremely small angles can be detected.

〔Effect of the invention〕

As described in detail above, the squareness measuring method of the present invention positions the object to be measured using the reference hole as a reference, so it is possible to accurately measure the squareness, and since it is optical and non-contact, it is possible to measure the squareness accurately. There is no influence from the external shape of the body, and since the device of the present invention uses a reflector to form the measurement beam, it has the advantage of being able to perform accurate measurements with a simple configuration.

In this example, the measurement beam was formed using a laser beam and a reflecting mirror.
It is not limited to this. Furthermore, various detection objects may be employed depending on the purpose and cost, such as visual inspection using a screen, line sensor, split sensor, ITV, etc. Furthermore, the number of measurement beams is not limited to three, and any number may be used, and for example, a single annular measurement beam with the reference measurement light at the center may be used.

[Brief explanation of drawings]

i Figure 1 is a configuration diagram of the device of the present invention, Figure 2 is the
FIG. 3 is a cross-sectional view of the object to be measured in the conventional example and the present invention; FIG. 4 is an explanatory diagram of the conventional measuring method. (3)...Reference hole, (4)...Center axis, (5)
...Flat surface, αq...Object to be measured, ■...Emission optical system, Q3...Reflector, a9...Holding stand, Cυ・
...Laser oscillator. (c)... Laser light, (to), @, @... optical path, (
25a), (26a), (27a)...first beam light, (25b), (26b), (27b)
...Second beam light, (25c), (26c), (
27c)...Measurement beam light, 0υ...Beam splitter, country...Detection object. Agent Patent Attorney Noriyuki Ken Yudo Takehana Kikuo Figure 1 Figure 2 Figure 3 Figure 1N4

Claims (6)

[Claims] (1) A perpendicularity measurement method for measuring the perpendicularity between the central axis and the flat part of an object having a reference hole and a flat part perpendicular to the central axis of the object, in which A plurality of measuring beams consisting of a first beam and a second beam traveling straight in the direction are projected in parallel to each other, and one of these measuring beams is used as a reference measuring beam. The method is characterized in that the object to be measured is positioned at a position passing through the reference hole, and the perpendicularity is determined by comparing the optical path of the reflected light of the measurement beam on a flat surface of the object to be measured and the optical path of the measurement beam. How to measure squareness. (2) The squareness measuring method according to claim 1, wherein either the first light beam or the second light beam is reflected light from the other. (3) The squareness measuring method according to claim 1 or 2, wherein the measurement beam is a laser beam. (4) A squareness measuring device for measuring the perpendicularity between the central axis and the flat part of a workpiece having a reference hole and a flat part perpendicular to the central axis thereof, the squareness measuring device having a plurality of parallel measuring devices. a projection optical system that projects a first beam of light; and a projection optical system that reflects the plurality of first beams and converts them into a plurality of second beams of light each having the same optical path as the first beam of light. a reflector that forms a plurality of measurement beams consisting of the first beam and the second beam; a beam splitter that is provided in the measurement beam and guides the measurement beams out of the optical path; a detection body that receives the derived measurement beam light and detects the position of the light reception; A squareness measuring device characterized by comprising a holding table for projecting the reflected light onto the detection object. (5) The squareness measuring device according to claim 4, wherein the beam projection optical system has a laser oscillator as a light source of the measurement beam light. (6) The squareness measuring device according to claim 4 or 5, wherein the detection object has a photoelectric conversion element in the light receiving part of the measurement beam light.