JP2009098092A - Relative height detector - Google Patents

Abstract

To provide a relative height detection device capable of detecting a relative height between two or three protruding points with a simple configuration with high accuracy.
A relative height detecting device includes an inclined display plate, and the inclined display plate is placed in a point contact state on spheres a and b to be measured placed on a reference surface 5a. An angle sensor 3 is incorporated in the tilted display plate 2, and the tilt angle of the tilted display plate 2 in a tilted posture corresponding to the height difference between the spheres a and b is measured by the angle sensor 3. The arithmetic device 4 detects the difference in height between the spheres a and b based on the tilt angle θx and the known distance L1 between the spheres a and b. Since a minute height difference between the spheres a and b appears as a relatively large tilt angle of the tilt display panel 2, the height difference between the spheres a and b can be detected with high resolution based on the tilt angle.
[Selection] Figure 1

Description

  The present invention relates to a relative height detection device that detects a difference in height between two or three points that is difficult to capture with an independent sensor. In particular, the present invention relates to a relative height detection device suitable for use in detecting variations in dimensions of parts such as a sphere and a cylinder used for rolling elements of a bearing.

  The requirements to measure the height difference between two or three points protruding from the plane with high accuracy are the height adjustment of the position control pin, the measurement of the sphere for the bearing and the diameter of the cylinder, the cylinder with the oil film attached It often appears for purposes such as measuring the straight shape of the busbar.

  When measuring the difference in height between two or three points using a single displacement meter, after measuring the height of the protrusion of the target measurement object, the relative height between the displacement meter and the measurement object is measured. In order not to change the height, high-precision scanning control is required in which the displacement meter is moved to another measurement object and the height of the protruding portion of the measurement object is measured. Similarly, when using a three-dimensional measuring machine, highly accurate scanning control is required. Although it is possible to employ a method in which a plurality of displacement meters are arranged at the target position and the change in the vertex position of the measurement object is measured, the apparatus configuration becomes large and the apparatus cost increases.

  Here, a micrometer is used to measure the diameter of the sphere and the diameter or length of the cylinder. A V block method is known as a relative comparison measurement method. For example, Patent Document 1 discloses a sphere size measuring method for measuring the diameter of a steel ball using a displacement measuring device provided with a contact that is brought into contact with the outer peripheral surface of the steel ball. Discloses an outer diameter measuring method for calculating the outer diameter of a sphere by receiving a laser beam irradiated from the side onto the sphere placed on the mounting table.

On the other hand, conventionally, there are known a method of measuring the tilt of the reflecting surface with an autocollimator and a method of measuring the tilt angle using a level.
Japanese Patent Laid-Open No. 11-47698 JP 2001-241938 A

  Measuring the diameter of a sphere or cylinder using a micrometer is effective for determining the average diameter of one sphere or one cylinder, but it is possible to directly measure the diameters of two spheres. In addition, the height difference between two points on the straight line of the cylinder cannot be directly compared and measured. Although the V block method can perform relative comparison measurement of the cylinder diameter and roundness, there is a problem that the taper of the cylinder cannot be easily measured.

  In order to use a three-dimensional measuring machine in a line through which a large number of parts flow, there is a problem that it takes too much time for measurement. In addition, it is not only difficult to obtain a displacement meter that can accurately capture the protruding part of a component, but even if it is obtained, a change in the zero point due to the drift of the displacement meter becomes a problem and is not suitable for highly accurate and stable measurement. .

  Here, using an autocollimator or level, the difference between the height of multiple pins, the difference in height between the vertices of multiple spheres, the difference in height between two points on a cylindrical straight bus, etc. In the past, no attention has been paid to accurately detecting the difference in height of the selected portion, and no such proposal has been made.

  In view of these points, the object of the present invention is to detect a minute height difference between protruding points to be measured with a simple configuration and simple operation with high accuracy. To propose a device.

In order to solve the above problems, the relative height detection device of the present invention is:
A reference plane for measurement;
An inclination display body capable of expressing an inclination due to a difference in height between the two measurement points when the point is brought into contact with the first measurement point and the second measurement point at a fixed interval protruding from the reference plane;
Angle measuring means for measuring the tilt angle of the tilt display body with respect to the reference plane;
And detecting means for detecting a relative height between the two measurement points based on the measured inclination angle.

  The tilt display body used in this case represents the tilt angle with respect to the reference plane of the straight line connecting the first and second measurement points on the orthogonal plane orthogonal to the reference plane including the first measurement point and the second measurement point. Anything that can do.

  If the inclination of the tilt display body is measured by, for example, an angle sensor incorporated in the tilt display body or an tilt angle detection means such as an autocollimator, the detection means measures the tilt angle and the first and second angles. Based on the distance between the measurement points, the relative height (height difference) between the first and second measurement points can be calculated.

  Here, the support points protruding from the reference plane are arranged at positions that are not aligned in a straight line with respect to the first and second measurement points, and the first and second measurement points are arranged as tilt display bodies. When the three points of the support point are brought into point contact, it is possible to use the one representing the inclination in two directions due to the difference in height between these three points. In this case, the angle measuring means measures the two tilt angles with respect to the reference surface of the tilted display body, and the detecting means determines the height difference between the first and second measurement points based on the two tilt angles measured. And the average height from the reference plane of the first and second measurement points can be detected.

  The tilt display body used in this case may be anything that can represent the tilt of the plane defined by the three points of the first measurement point, the second measurement point, and the support point with respect to the reference plane.

  The relative height detection device of the present invention can be used to detect the relative heights of the vertices of the first measurement object and the second measurement object placed on the reference surface at regular intervals.

  In this case, the sample stage that supports a large number of measurement objects on the reference plane at known intervals, and the apexes of the measurement objects supported on the sample stage are sequentially set as the first measurement point and the second measurement point. It is desirable to have a configuration including a moving means for relatively moving the measurement object and the tilt display body so as to be positioned. For example, the relative heights of two measurement objects can be sequentially detected by intermittently moving a plurality of measurement objects along a linear or circular relative movement path.

  Here, a typical measurement object is a sphere, or a columnar body or a cylindrical body placed horizontally on a reference surface. For example, the relative height detection device of the present invention can be used for measuring the variation in the relative height of the rolling elements of the bearing.

  Moreover, the relative height detection apparatus of the present invention can be used to detect the relative heights of two different points on the same measurement object placed on the reference surface. For example, it can be used to detect the difference in height between two points on a straight generatrix in a cylinder or cylinder placed horizontally on a reference surface.

  Next, when the relative height detection device of the present invention is used to detect the relative heights of the three measurement points, the first measurement point and the second measurement point at a fixed interval protruding from the reference plane. When the point and the third measurement point are brought into point contact, an inclination display body that can represent a two-way inclination due to the difference in height of these three measurement points is used, and the angle measurement means uses the inclination display body. The inclination angle in two directions with respect to the reference plane may be measured, and the relative height of the three measurement points may be detected by the detection means based on the measured inclination angle in the two directions.

  In this case, the tilt display body only needs to represent the tilt of the plane defined by the three points of the first measurement point, the second measurement point, and the third measurement point with respect to the reference plane.

  The relative height detection device of the present invention having this configuration can be used to detect the relative heights of the vertices of the first, second, and third measurement objects placed on the reference surface at regular intervals. For example, the relative height of a sphere such as a rolling element of a bearing can be detected. It can also be used to detect the relative height of three points on the same measurement object such as a machine part.

  The relative height detection device of the present invention has an inclination display body arranged so as to make point contact with two or three points to be measured, and the inclination angle of one or two directions of the inclination display body is measured and measured. Based on the inclination angle, the height difference between two or three points or the average height of the two points is detected.

  According to the present invention, a minute height difference between points to be measured can be expressed as a relatively large tilt angle by the tilt display, so that the height can be simply and extremely high with a single displacement meter. Can be detected.

  Embodiments of a relative height detection apparatus to which the present invention is applied will be described below with reference to the drawings.

(Embodiment 1)
FIG. 1 is an explanatory diagram showing the principle of a relative height detection apparatus according to Embodiment 1 to which the present invention is applied. The relative height detection device 1 includes an inclination display plate 2 that can represent the inclination of a surface that is in contact with two points that should know the relative height, an angle sensor 3 that measures the inclination angle of the inclination display plate 2, and an angle sensor 3. And an arithmetic unit 4 composed of a computer or the like that calculates the height difference between the two points based on the measured tilt angle. The angle sensor 3 is, for example, integrated with the tilt display plate 2 and uses a sensor that can measure the tilt without being influenced by the tilt component orthogonal to the target direction.

  The measurement objects are, for example, spheres a and b. In this case, the relative height detection device 1 is provided with a reference surface 5a on which the spheres a and b can be placed so as not to move at a constant known interval. A stand 5 is provided.

  The inclined display plate 2 has a flat back surface 2a so that it can be placed on the spheres a and b in a point contact state. When the inclined display plate 2 is placed on the two spheres a and b placed on the reference surface 5a, the back surface 2a contacts the spheres a and b at two points (first measurement point A and second measurement point B). . On the orthogonal plane Sx orthogonal to the reference plane 5a including the first and second measurement points A and B, the inclination angle θx formed by the line segment Lx connecting the first and second measurement points A and B with the reference plane 5a is , Measured by the angle sensor 3.

  The tilted display board 2 is supported by support means (not shown) in a vertically swingable manner about the axis 2c perpendicular to the orthogonal plane Sx, and the height of the first and second measurement points A and B is determined. An inclined posture corresponding to the difference is formed, and is held so as not to move in that state.

  The distance L1 between the two spheres a and b placed on the reference surface 5a is known, and the arithmetic device 4 determines the difference in height between the first and second measurement points A and B based on the distance L and the inclination angle θ1. Can be calculated. In other words, the diameter difference between the spheres a and b can be calculated. Since a minute height difference between the two points A and B appears as a relatively large tilt angle by the tilted display plate 2, the height difference can be measured with extremely high resolution.

  If a master sphere serving as a measurement standard with a known diameter is used as one sphere, for example, sphere a, the height (diameter) of the other sphere b can also be calculated.

  Further, the tilt angle of the tilted display plate 2 can be measured using an optical displacement meter such as an autocollimator. For example, if the front surface 2b of the tilted display plate 2 is a flat reflecting surface parallel to the back surface 2a, the flat reflecting surface is irradiated with the detection light from the orthogonal surface Sx, and the tilt angle is calculated from the reflection angle of the reflected light. Good.

  Furthermore, the object to be measured may be a shape other than a sphere, a cylinder, a cylinder, a polyhedron, or the like. For example, when detecting the height of a cylindrical body or prismatic body, as shown in FIG. 2, measurement is performed by point contact such as a sphere 6, a hemisphere 7, a cone or a quadrangular pyramid 8 on the back surface as an inclined display body. A part that can be placed on the object may be formed.

(Modification of Embodiment 1)
FIG. 3 is an explanatory diagram showing the principle of a relative height detection device according to a modification of the first embodiment. The relative height detection device 1A can be used, for example, for selecting a cylindrical body (cylindrical body) a1. The relative height detection device 1A includes an inclination display plate 2A that can represent the inclination of a surface that is in contact with two points whose relative height is to be known, a two-dimensional angle sensor 3A that measures the inclination angle of the inclination display plate 2A, an angle And an arithmetic unit 4A composed of a computer or the like that calculates the height difference between the two points based on the tilt angle measured by the sensor 3A.

  The tilted display board 2A is supported in a state that it can swing up and down around an axis extending in the x direction and an axis extending in the y direction in the figure. The angle sensor 3A is integrated with, for example, the tilted display board 2A, and a sensor that can measure tilt angles θx and θy in the x direction and the y direction in the figure is used. On the reference surface 5a of the sample stage 5 on which the object to be measured is placed, a position on which a support sphere c that defines the support point C of the tilted display plate 2A is placed.

  A pair of semicircular cross-section members 2d are attached to the back surface 2a of the inclined display plate 2A so as to make point contact with two points along the straight line of the cylindrical body a1 of the measurement object. On the reference surface 5a, the cylindrical body a1 to be measured is placed in a horizontal state in the y-axis direction, and the inclined display plate 2A is placed on the cylindrical body a1 and the support sphere c. As a result, the inclined display plate 2A is in contact with the cylindrical body a1 at the first measurement point A and the second measurement point B, and is in contact with the support sphere c at the support point C. For this reason, the inclined display board 2A represents the inclination of the plane S defined by these three points with respect to the reference plane 5a. Therefore, the two-dimensional angle sensor 3A incorporated in the tilted display board 2A measures the tilt angle θx in the x direction and the tilt angle θy in the y direction orthogonal thereto.

  In the illustrated example, the inclination angle θx is an angle corresponding to the height difference between the two points A and B in the linear generatrix direction of the cylindrical body a1 to be measured, and the inclination angle θy is relative to the reference plane 5a of the two points A and B. The angle corresponding to the average height. In the arithmetic unit 4A, based on the known distance Ly between the two points, the distance Ly in the x direction between the cylindrical body a1 and the support sphere c, and the height (diameter) of the support sphere c, the two points A and B The height difference (taper) and the average height (average diameter) of these two points can be calculated. A spherical bearing can be used instead of the support sphere c.

(Embodiment 2)
FIG. 4 is an explanatory view showing the principle of a relative height detection apparatus according to Embodiment 2 to which the present invention is applied. This relative height detection device 11 has a slight difference in height between three points that should be at the same height, for example, three-point supporting pins for precision parts, or three spheres preferably having the same dimensions. Can be measured with extremely high resolution by measuring the inclination of a plane represented by an inclined display supported by three points.

  The relative height detection device 11 includes an inclination display plate 12 that can represent the inclination of a surface that is in contact with three points whose relative height should be known, a two-dimensional angle sensor 13 that measures the inclination angle of the inclination display plate 12, an angle And an arithmetic unit 14 composed of a computer or the like that calculates the height difference between the three points based on the tilt angle measured by the sensor 13. The angle sensor 13 is integrated with the tilted display board 12, for example, and can measure tilt angles in the x and y directions.

  The measurement objects are, for example, spheres a, b, and c. In this case, the relative height detection device 11 can mount the spheres a, b, and c so that they do not move at a constant known interval. Is provided with a sample stage 15. The spheres a, b, and c are placed at positions that do not line up on a straight line on the reference surface 15a.

  The inclined display plate 12 has a flat back surface 12a so that it can be placed on the spheres a, b, and c in a point contact state. When the inclined display plate 12 is placed on the three spheres a, b, and c placed on the reference surface 15a, the back surface 12a has three points (first measurement point A, second measurement point B, and third measurement point C). ) Touches the spheres a, b and c. The two-dimensional angle sensor 13 measures the two-direction inclination angles θx and θy representing the inclination of the plane S including the first, second, and third measurement points A, B, and C with respect to the reference surface 15a. The tilt display plate 12 is supported by a support means (not shown) so that it can be tilted freely in two axial directions according to the height positions of the three measurement points.

  Here, one of the three measurement points, for example, the measurement point C can be replaced with a support mechanism having a known height such as a spherical bearing mechanism. For example, by forming a concave spherical surface on the inclined display body 12 side and supporting this part with a complementary convex member, the measurement point C can be used as a height reference point. The tilt display plate 12 can be supported with the point being the center without restraining the tilt in the biaxial direction. In this way, the height difference between the two measurement points A and B and the respective heights can be detected.

  That is, if the diameter of one sphere c is used as a reference, the difference in diameter between the other two spheres, the average value of the diameters of the two spheres, and the difference between the reference spheres can be determined from the inclination angles in the two directions. Therefore, the diameter difference between each of the other two spheres with respect to the reference sphere can be detected.

  Here, in the above example, the reference surface 15a on which the sphere of the measurement object is placed is a flat surface. Instead of this, a sphere to be measured may be arranged in a triangular pyramid groove formed at three appropriate positions on the reference plane, and placed on the reference plane so as not to move the sphere. In this case, the error in the support position depth of the sphere in the three grooves becomes a problem due to the planar shape deviation of the back surface 12a of the tilted display plate 12 in contact with the apexes of the three spheres.

  For such a deviation, a so-called inversion method is applied in which the positions of the grooves into which the two spheres are inserted are changed, and the spherical support position depth of the two grooves is determined from the difference between the two measured values before and after the inversion. The combined error between the error and the planar shape deviation of the back surface 12a of the tilted display plate 12 can be detected separately. In addition, for the remaining sphere, if a similar reversal operation is applied, three height errors can be compensated.

  In this way, the height error of each groove is detected and the reference sphere is determined. Thereafter, the spheres to be measured are sequentially arranged in the two grooves, and the diameter difference between the spheres is detected. I can go.

  Note that the holding groove for holding the sphere may be a conical groove instead of the triangular pyramid groove. Alternatively, three pin gauges may be arranged in a conical shape, and the sphere to be measured may be held by a three-point support mechanism defined by three lines. If the measurement is repeated by changing the position of the three points where the sphere is in contact, such as by blowing air from the asymmetrical direction, the effect of the spherical shape deviation of the sphere will be eliminated. Thus, the average diameter can be calculated.

(Embodiment 3)
FIG. 5 is an explanatory view showing a relative height detection apparatus according to Embodiment 3 to which the present invention is applied. The relative height detection device 21 includes a tilt display plate 22, a two-dimensional angle sensor 23 incorporated in the tilt display plate 22, and a tilt in the biaxial direction of the tilt display plate 22 measured by the two-dimensional angle sensor 23. The calculation device 24 that detects the variation in the diameter of the sphere to be measured and the change in average height based on the angle, and the sphere a (n) (n = 1, 2, 3,. And a moving stage 25 that moves along a moving path in the x direction passing through.

  The moving stage 25 is formed with a linear V-groove 26 that defines a reference surface for placing the sphere a (n) to be selected. A large number of spheres a (n) are arranged in a straight line in the V groove 26 in contact with each other.

  The inclined display plate 22 has a pair of protrusions 22d that can make point contact with the vertices of two adjacently arranged spheres on the back surface 22a of the tip located on the moving path of the sphere by the moving stage 25. . Further, the back surface of the rear end portion of the inclined display plate 22 is supported by, for example, a spherical bearing 27. The height of the support point by this spherical bearing 27 is known.

  In the dimension sorting apparatus 21 having this configuration, while the moving stage 25 is intermittently fed in the x direction at a constant feed pitch, the projections 22d of the inclined display plate 22 are sequentially brought into contact with the two spheres, and the two The difference in sphere height and the change in average height of the two spheres are measured.

  When only the difference in height between the two measurement points is detected, the inclination angle display plate 22 may be supported in a state having a degree of freedom only in the pitching direction indicated by an arrow 28 in the figure, and the angle sensor 23 is also pitched. A one-dimensional angle sensor that can detect only the angle of the direction may be used.

  In addition, it is possible to correct the accumulation of accidental errors by providing spheres with known dimensions or dimensional reference points that represent reference vertex heights at some positions in the middle of the V-groove 26 that supports the sphere. Also good.

  Furthermore, a holder that holds a plurality of spheres to be measured at regular intervals may be detachably attached to the V groove 26 of the moving stage 25.

  Further, as shown in FIG. 6, the spheres to be measured are arranged at regular intervals in the circumferential direction, and the tilted display body is relatively rotated around the center to sequentially detect the height difference between adjacent spheres. It is also possible to do. In FIG. 6, parts corresponding to the respective parts in FIG. 5 are denoted with the same reference numerals.

It is explanatory drawing of the relative height detection apparatus which concerns on Embodiment 1 to which this invention is applied. It is explanatory drawing which shows the modification of the relative height detection apparatus of FIG. It is explanatory drawing which shows the modification of the relative height detection apparatus of FIG. It is explanatory drawing of the relative height detection apparatus which concerns on Embodiment 2 to which this invention is applied. It is explanatory drawing of the relative height detection apparatus which concerns on Embodiment 3 to which this invention is applied. It is explanatory drawing which shows the modification of the relative height detection apparatus of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 11, 21 Relative height detection apparatus 2, 2A, 12, 22 Inclined display board 2a, 12a, 22a Back surface 2b Front surface 2c Axis 2d Member 3, 3A, 13, 23 Angle sensor 4, 4A, 14, 24 Calculation apparatus 5, 15, 25 Sample stage 5a, 15a, reference plane 6 sphere 7 hemisphere 8 quadrangular pyramid 22d protrusion 26 V groove 27 spherical bearing A first measurement point B second measurement point C third measurement point (support point)
a, b Sphere c Cylinder (Cylinder)

Claims (16)

A reference plane for measurement;
An inclination display body capable of expressing an inclination due to a difference in height between the two measurement points when the point is brought into contact with the first measurement point and the second measurement point at a fixed interval protruding from the reference plane;
Angle measuring means for measuring the tilt angle of the tilt display body with respect to the reference plane;
A relative height detection device comprising detection means for detecting a relative height between the two measurement points based on the measured inclination angle. The relative height detection device according to claim 1,
The inclined display body represents an inclination angle of a straight line connecting the first and second measurement points with respect to the reference surface on an orthogonal plane orthogonal to the reference plane including the first measurement point and the second measurement point. A relative height detector characterized by the above. The relative height detection device according to claim 1,
Having a support point protruding from the reference plane;
This support point is arranged at a position that does not line up linearly with respect to the first and second measurement points,
When the tilt display body is brought into point contact with the three points of the first and second measurement points and the support point, the tilt display body represents a tilt in two directions due to a difference in height between these three points.
The angle measuring means measures an inclination angle in two directions with respect to the reference surface of the inclined display body,
The detection means detects a height difference between the first and second measurement points and an average height of the first and second measurement points from the reference plane based on the measured inclination angles in the two directions. Relative height detector characterized by. The relative height detection device according to claim 3,
The relative height detection device, wherein the tilt display body represents a tilt of a plane defined by three points of the first measurement point, the second measurement point, and the support point with respect to the reference plane. In the relative height detection device according to any one of claims 1 to 4,
The relative height detection device, wherein the first measurement point and the second measurement point are vertices of a first measurement object and a second measurement object placed on the reference plane at regular intervals. The relative height detection device according to claim 5,
A sample stage for supporting a large number of objects to be measured on the reference surface at known intervals;
Moving means for relatively moving the measurement object and the tilt display body so that the vertexes of the measurement object supported on the sample stage are sequentially positioned at the first measurement point and the second measurement point; A relative height detection device characterized by comprising: The relative height detection device according to claim 5 or 6,
The relative height detection device, wherein the measurement object is a sphere, or a columnar body or a cylindrical body placed horizontally on the reference surface. The relative height detection device according to claim 5 or 6,
The relative height detection device, wherein the measurement object is a rolling element of a bearing. In the relative height detection device according to any one of claims 1 to 4,
The first height measurement point and the second height measurement point are two points on the same measurement object. The relative height detection device according to claim 9,
The relative height detection device, wherein the measurement object is a cylindrical body or a cylindrical body placed horizontally on the reference surface. A reference plane for measurement;
When point contact is made with the first measurement point, the second measurement point, and the third measurement point at a fixed interval protruding from the reference plane, the inclination in two directions due to the difference in height of these three measurement points is expressed. A tilt indicator that can
Angle measuring means for measuring an inclination angle in two directions with respect to the reference plane of the tilt display body;
A relative height detection device comprising detection means for detecting a relative height of the three measurement points based on the measured inclination angles in the two directions. The relative height detection device according to claim 11,
The relative height detection device, wherein the tilt display body represents a tilt of a plane defined by three points of the first measurement point, the second measurement point, and the third measurement point with respect to the reference plane. The relative height detection device according to claim 11 or 12,
The relative height detection device, wherein the first, second, and third measurement points are vertices of first, second, and third measurement objects placed on the reference plane at regular intervals. The relative height detection device according to claim 13,
The relative height detection device, wherein the measurement object is a sphere. The relative height detection device according to claim 14,
The relative height detection device, wherein the measurement object is a rolling element of a bearing. The relative height detection device according to claim 11 or 12,
The first measurement point, the second measurement point, and the third measurement point are three points on the same measurement object such as a machine part.

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