JP6686376B2 - Measuring device and measuring method - Google Patents

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring device and a measuring method, for example, a device and a method for measuring a diameter of a bearing ring for a rolling bearing in a raceway.

For example, the raceway formed on the outer peripheral surface of the inner ring of a ball bearing is formed as a groove with an arcuate cross section, and the minimum diameter of this groove, that is, the diameter at the groove bottom position is measured to confirm the processing dimensions. (Inspection) etc. are performed (for example, refer to Patent Document 1).
The following devices are known as devices for performing such measurement. As shown in FIG. 8, the measuring device includes a first contact 91, a second contact 92, a third contact 93, a movable member 94 on which the third contact 93 is mounted, and a movable member 94 as a reference line. It has a guide member 95 for guiding along L0, an elastic member (compression spring) 96 for pressing the third contactor 93 against the track 98, and a displacement gauge 97.

  In order to measure the diameter D of the track 98, the three contacts 91, 92, 93 are brought into contact with the track 98. The first contactor 91 and the second contactor 92 are arranged in line symmetry about the reference line L0 as an axis and are fixed to the apparatus base, while the third contactor 93 is along the reference line L0. It is possible to move. Therefore, the displacement amount of the movable member 94 carrying the third contactor 93 is measured by the displacement meter 97, and the diameter D at the groove bottom position of the track 98 is obtained based on the measured value.

  In the process of obtaining the diameter D, the displacement amount 97 has already obtained the amount of movement of the movable member 94 for the inner ring (work master) whose dimensions are known. Then, using the processed inner ring 99 as an actual measurement target, the movement amount of the movable member 94 is obtained by the displacement meter 97, and the measured value by the work master is used as a reference, based on the measured value of the inner ring 99 that is the actual measurement target. The diameter D of the track 98 is determined.

JP 2006-47060 A (see FIG. 2)

  The guide member 95 shown in FIG. 8 has a linear rail and a plurality of balls interposed between the linear rail and the movable member 94, and the plurality of balls roll to move the movable member 94. It is configured to move along a straight rail. In order to move the movable member 94 smoothly, a small gap is formed between the members forming the guide member 95. Therefore, when the elastic member 96 pushes the movable member 94 in order to apply the measured load to the inner ring 99, the movable member 94 slightly moves around the contact position of the third contact 93 with the track 98, as shown in FIG. In some cases, the movable member 94 may be tilted by a small angle with respect to the reference line L0. Note that in FIG. 9, the tilt of the movable member 94 is described to be larger than in the actual case for the sake of easy understanding.

In the state shown in FIG. 9, the measurement value of the displacement meter 97 includes an error δ caused by the inclination of the movable member 94 in addition to the actual displacement amount of the movable member 94 in the reference line L0 direction. There is a problem that a measurement error occurs in the diameter D of the track 98.
The above description is for the case where the measurement target is the inner ring 99 of the ball bearing, but the same applies to the case of measuring the trajectory formed on the inner peripheral surface of the outer ring of the ball bearing. That is, in the case of the outer ring, the measuring device has a structure in which the three contacts are brought into contact with the orbit of the outer ring from the inside in the radial direction. Even in this case, the movable member with respect to the guide member 95 can be applied by applying the measurement load. If the straightness of 94 is unstable, the displacement meter 97 does not follow the actual amount of movement, causing a measurement error, which is a similar problem.

  Therefore, an object of the present invention is to provide a measuring device and a measuring method capable of reducing a measurement error as much as possible even if the straightness of the movable member relative to the guide member is unstable. To do.

The present invention has a first contactor and a second contactor that are arranged in line symmetry about a reference line, and a third contactor that is located on the reference line, and is installed with a point on the reference line as the center. Either one of the outer peripheral surface and the inner peripheral surface of the cylindrical work to be measured, by contacting the first contactor, the second contactor and the third contactor, in the measurement target surface A measuring device for measuring a diameter, which is arranged line-symmetrically with a movable member on which the third contact is mounted and the reference line as an axis, and guides the movable member along the reference line. A first guide member and a second guide member, an elastic member for urging the movable member in a direction parallel to the reference line to press the third contactor against the measurement target surface, and the movable member. first meter that is line symmetrical to the reference line of the member as an axis A first displacement gauge and a second displacement gauge for measuring a displacement amount of the movable member in position and the second measurement position, the average value of the measurement values of the first displacement gauge and the second displacement gauge, the average An arithmetic unit for determining the diameter based on a value , wherein the elastic member is line-symmetrical with respect to the reference line, in order to press a first pressing position and a second pressing position of the movable member. A distance in the orthogonal direction orthogonal to the reference line from the first guide member to the reference line, including a first elastic member and a second elastic member provided on both sides of the reference line. And a distance in the orthogonal direction from the second guide member to the reference line, a distance in the orthogonal direction from the first pressing position to the reference line and from the second pressing position to the reference line Directly above Greater than the distance in the direction.

  This measuring device includes a first displacement meter and a second displacement meter whose measurement positions are two positions that are line-symmetric with respect to the reference line as an axis, in order to measure the displacement amount of the movable member. Therefore, the straightness of the movable member with respect to the guide member is unstable, and the movable member rotates about the contact position of the third contact with the surface to be measured, and is inclined with respect to the reference line. Even if this happens, the amount of displacement of the movable member can be obtained more accurately by correcting it using the measurement values of the first displacement meter and the measurement value of the second displacement meter, and the measurement error of the diameter on the measurement target surface can be reduced. It can be reduced as much as possible.

In this case, as the correction process, the average value of the measurement values of the first displacement meter and the second displacement meter is obtained.
Further, the movable member is easily pushed in the direction parallel to the reference line, and the inclination of the movable member can be suppressed as much as possible.

Further, it is preferable that the arithmetic device obtains the diameter of the cylindrical work on the measurement target surface by using the average value and the diameter of the work master on the measurement target surface.
In this case, the diameter of the cylindrical work on the measurement target surface can be obtained by comparison with a work master whose dimensions (diameter on the measurement target surface) are known.

Further, the present invention uses the above-described measuring apparatus, the a first contact and said second contact, a third contact located on the reference line, cylinder placed around the one point of the reference line A method for measuring the diameter of the work surface by contacting one of the outer work surface and the inner work surface, which is a movable member carrying the third contact. Is guided in a direction parallel to the reference line by the first guide member and the second guide member to bring the third contactor into contact with the measurement target surface, and further, the third contactor is subjected to the measurement. A step of bringing the first contactor and the second contactor into contact with the measurement target surface while pressing against the target surface, and the movable member at the first measurement position and the second measurement position. Before measuring the displacement amount of To determine the diameter of the object surface, and a, a step of determining the average value of the displacement amount in the first measurement position and the second measurement position.

  According to this measuring method, in order to measure the displacement amount of the movable member, the displacement amount of the movable member is measured with two positions that are line-symmetrical with respect to the reference line as the measurement position, and the average value of these displacement amounts. Are seeking. Therefore, the straightness of the movable member with respect to the guide member is unstable, and the movable member rotates about the contact position of the third contact with the surface to be measured, and is inclined with respect to the reference line. Even if it does not occur, the displacement amount of the movable member can be obtained more accurately by averaging the measurement values at the two measurement positions, and the measurement error of the diameter on the measurement target surface can be reduced as much as possible. It will be possible.

  According to the present invention, the displacement amount of the movable member can be obtained more accurately, and the measurement error of the diameter of the measurement target surface can be reduced as much as possible. Thereby, the accuracy of the product including the cylindrical work can be improved.

It is a top view which shows the outline of one Embodiment of a measuring device. It is sectional drawing which looked at the measuring apparatus shown in FIG. 1 from the side. It is a flowchart figure explaining a measuring method. It is a schematic diagram of a measuring device for explaining a process included in a measuring method. It is a schematic diagram of a measuring device for explaining a process included in a measuring method. It is a top view of a measuring device when an object of measurement is an outer ring. It is sectional drawing which looked at the measuring apparatus shown in FIG. 6 from the side. It is a schematic diagram of the conventional measuring device. It is a schematic diagram of the conventional measuring device.

Embodiments of the present invention will be described below with reference to the drawings.
[About measuring device]
FIG. 1 is a plan view showing the outline of an embodiment of a measuring apparatus. FIG. 2 is a cross-sectional view of the measuring device shown in FIG. 1 viewed from the side. The measuring apparatus 10 uses either (a part of) the outer peripheral surface or the inner peripheral surface of the cylindrical work as a measurement target surface, and is for measuring the diameter of the measurement target surface. The measuring device 10 shown in FIGS. 1 and 2 is a device for measuring the diameter of the outer peripheral surface of a cylindrical work, and particularly in the present embodiment, the cylindrical work is the inner ring 4 for ball bearings. This is for measuring the diameter D of the track 5 formed on the outer peripheral surface. Since the raceway 5 of the inner ring 4 of the ball bearing is formed as a groove having an arc-shaped cross section, the minimum diameter of this groove, that is, the diameter D at the groove bottom position is measured. That is, the trajectory 5 is the measurement target surface.

  The measuring device 10 includes a first contactor 11, a second contactor 12, a third contactor 13, a movable member 20, guide members 31, 32, an elastic member 25, a first displacement meter 41, and a second displacement meter 42. I have it. Further, the measuring device 10 includes a device base 9 installed on the workbench, and a fixing member 19 fixed to the device base 9. Further, the measuring device 10 includes a work receiving portion 38 and a calculation device 15.

The device base 9 is a flat plate-shaped member on which the above-described devices are provided.
The fixing member 19 is fixed to the device base 9, and includes a fixing block 19a and a plurality of rods 19b extending from the fixing block 19a in a direction parallel to the reference line L0.
In this measuring apparatus 10, the reference line L0 is defined. In FIG. 1, a reference line L0 is a vertical bisector of a line segment connecting a contact point between the first contact 11 and the track 5 and a contact point between the second contact 12 and the track 5, and is a device base. It is a straight line (horizontal straight line in this embodiment) parallel to the surface direction of the table 9. The reference line L0 serves as a reference for the arrangement of each device and the position of the inner ring 4 to be measured. As will be described later in the measuring method, the diameter of the track 5 is set by aligning one point Q on the reference line L0 with the center of the inner ring 4 (center point C) and installing the inner ring 4 in the measuring device 10. The measurement of D is performed.

  The work receiving portion 38 is for supporting the inner ring 4 from below, and has a horizontal beam portion 38a on which the inner ring 4 is placed and a column portion 38b that supports the horizontal beam portion 38a. The horizontal beam portion 38a has a Y shape in a plan view, and the inner ring 4 can be placed on the upper surface thereof. The upper surface (mounting surface) of the horizontal beam portion 38a is parallel to the reference line L0 and constitutes a horizontal plane. The column portion 38b is attached to the device base 9 and supports the horizontal beam portion 38a.

  The first contactor 11 and the second contactor 12 are attached to a support member 14 fixed to the device base 9, respectively, and these contactors 11 and 12 are located at the same height, and are viewed in a plan view. (See FIG. 1), they are arranged in line symmetry with the reference line L0 as an axis. The first contactor 11 and the second contactor 12 have a ball shape and make point contact with the track 5 of the inner ring 4 mounted on the work receiving portion 38.

  On the device base 9, the first contact 11 and the second contact 12 are in a fixed state, while the third contact 13 is movable. The third contact 13 is located at the same height as the first contact 11 and the second contact 12 (see FIG. 2), and is located on the reference line L0 in plan view (see FIG. 1). ing. That is, the third contact 13 is movable along the reference line L0. The movable member 20 and the guide members 31 and 32 are provided in order to make the third contact 13 movable. The third contactor 13 has a ball shape, and is in point contact with the track 5 of the inner ring 4 mounted on the work receiving portion 38.

The guide members 31 and 32 of the present embodiment are LM guides (registered trademark), and the guide members 31 and 32 are arranged in line symmetry about the reference line L0 as an axis in a plan view. These guide members 31 and 32 are arranged in parallel, and are configured to movably support a movable member 20 (a movable base 20a described later) with a direction parallel to the reference line L0 as a guiding direction. The movable member 20 has a movable base 20a movable along the guide members 31 and 32, and a support member 20b fixed to the movable base 20a. The third contact 13 is attached to the support member 20b.
As described above, the movable member 20 is mounted with the third contact 13 and is movable in the direction parallel to the reference line L0, and the guide members 31 and 32 guide the movable member 20 along the reference line L0. The configuration is obtained.

  A plurality of through holes 20c parallel to the reference line L0 are formed in a part 20d of the movable base 20a, and the rod 19b is inserted therethrough. An elastic member 25 formed of a coil spring is provided between the fixed block 19a and a part 20d of the movable base 20a so as to be fitted on the rod 19b. In this embodiment, the elastic member 25 is a compression coil spring. Accordingly, the elastic member 25 can press the third contact 13 mounted on the movable member 20 against the track 5.

  In the present embodiment, the pair of rods 19b (a pair of upper and lower sides in FIG. 1) are provided in a line-symmetrical arrangement about the reference line L0 as an axis, and therefore the elastic members 25 provided along the rods 19b. Also, the configuration is provided on both sides of the reference line L0 with respect to each other, so that the pair of elastic members 25 are line-symmetric with respect to the reference line L0 of the movable base 20a of the movable member 20 as an axis. The pressing positions P1 and P2 can be pressed. With this configuration, the movable member 20 is easily pushed in the direction parallel to the reference line L0, and the inclination of the movable member 20 can be suppressed as much as possible. The shape (length) and elastic coefficient of the pair of elastic members 25 are the same.

  In addition to this structure, the elastic member 25 may be provided on the central rod 19b. The elastic member 25 urges the movable member 20 in a direction parallel to the reference line L0 regardless of whether the elastic member 25 is provided on the rods 19b on both sides or the central rod 19b. A configuration in which the third contact 13 can be pressed against the track 5 is obtained.

  The movable base 20a is provided with left and right levers 26 operated by an operator. The levers 26 are arranged in line symmetry about the reference line L0 as an axis in a plan view. By pulling the lever 26, it is possible to separate the movable member 20 (third contact 13) from the first contact 11 and the second contact 12 against the elastic force of the elastic member 25. Then, when the force pulling the lever 26 is released, the movable member 20 (third contact 13) moves in the direction of approaching the first contact 11 and the second contact 12 due to the elastic force (restoring force) of the elastic member 25. Then, the third contact 13 comes into contact with the track 5 and can be further pressed.

  The first displacement meter 41 and the second displacement meter 42 measure the amount of displacement of the movable member 20 in the direction along the reference line L0, and are contact-type sensors in this embodiment, and are the same for both. is there. The displacement meter 41 (42) has a main body 41a (42a) and a terminal 41b (42b) that moves back and forth in a direction parallel to the reference line L0 with respect to the main body 41a (42a), and is movable. The amount of movement of the terminal 41b (42b) contacting the member 20 is output as a detection signal. The first displacement meter 41 and the second displacement meter 42 may be non-contact type sensors. The first displacement meter 41 and the second displacement meter 42 are independently used for measurement, and output a measurement value (measurement signal) to the arithmetic unit 15. The terminals 41b (42b) are in point contact with the flat surface of the movable base 20a of the movable member 20, and the first displacement meter 41 and the second displacement meter 42 measure the displacement amount of the movable member 20.

  The first displacement meter 41 and the second displacement meter 42 are arranged in line symmetry about the reference line L0 as an axis in a plan view, and the detection direction is parallel to the reference line L0. As a result, the first displacement meter 41 and the second displacement meter 42 measure the displacement amount of the movable member 20 with two positions that are line-symmetrical with respect to the reference line L0 in the movable member 20 as measurement positions P11 and P12. Measure each.

  The displacement amount of the movable member 20 becomes equal to the displacement amount of the third contact 13, and the first displacement meter 41 and the second displacement meter 42 acquire the same measured value (displacement amount) in design. However, if the straightness of the movable member 20 with respect to the guide members 31 and 32 becomes unstable, the movable member 20 rotates about the contact position of the third contact 13 with the track 5, and the movable member 20 moves to the reference line. When it is tilted with respect to L0, the first displacement meter 41 and the second displacement meter 42 obtain different measurement values (displacement amounts). These different measurement values (displacement amounts) can be called temporary displacement amounts.

  The calculation device 15 is composed of, for example, a computer device that performs various calculations, and performs a process of obtaining an average value of measurement values (temporary displacement amount) of the first displacement meter 41 and the second displacement meter 42. Further, the arithmetic unit 15 of the present embodiment also performs a process of obtaining the diameter D of the track 5 using this average value. These processes will be described later in the measuring method.

In the measuring device 10 of the present embodiment, the first contactor 11, the second contactor 12, and the third contactor 13 are arranged on one virtual circle centered on the point Q on the reference line L0. In this state, the points Q are evenly arranged in the circumferential direction. That is, the contacts 11, 12, 13 are arranged at a pitch of 120 degrees. Then, as described above, the first contactor 11 and the second contactor 12 are arranged in line symmetry about the reference line L0 as an axis in the plan view, and the third contactor 13 is placed on the reference line L0. Since it is located, as described above, the vertical bisector of the line segment connecting the contact point between the first contact 11 and the track 5 and the contact point between the second contact 12 and the track 5, It matches the reference line L0.
The three contacts 11, 12, 13 do not have to be evenly arranged in the circumferential direction, but the first contact 11 and the second contact 12 are arranged in line symmetry about the reference line L0. Yes, the third contact 13 must be located on the reference line L0. Then, the third contact 13 is movable along the reference line L0.

[About measurement method]
A measuring method performed by the measuring device 10 having the above configuration will be described.
In this measuring method, the inner ring 4 is installed around a point Q on the reference line L0 of the measuring device 10 and is fixed to a track 5 (measurement target surface) formed on the outer peripheral surface of the inner ring 4. This is a method of measuring a diameter D on the track 5 by bringing a certain first contactor 11 and a second contactor 12 into contact with a movable third contactor 13. The measurement method includes a preparation step St1, a measurement step St2, and a calculation step St3 (see FIG. 3). 4 and 5 are schematic views of the measuring apparatus 10 for explaining each step.

  In the preparatory step St1, as shown in FIG. 4, in order to install the inner ring 4 between the three contacts 11, 12, 13, the operator pulls the lever 26 (see FIG. 1) to move the elasticity of the elastic member 25. The third contact 13 mounted on the movable member 20 is positioned away from the first contact 11 and the second contact 12 against the force. Then, by releasing the pulling force of the lever 26, the elastic member 25 pushes the movable member 20 on which the third contact 13 is mounted by the elastic force (restoring force), and the movable member 20 is referred to by the guide members 31 and 32. By guiding in a direction parallel to the line L0, the third contact 13 is brought into contact with the track 5 as shown in FIG. 5, and the third contact 13 is pressed against the track 5 by the elastic force. At the same time, the first contact 11 and the second contact 12 are in contact with the track 5. A measurement load is applied to the inner ring 4 by the force of the elastic member 25.

In the next measuring step St2, the displacement amount of the movable member 20 (movable base 20a) by the first displacement meter 41 and the second displacement meter 42 is measured in a state where the measured load is applied to the inner ring 4.
In this measurement step St2, two positions that are line-symmetrical with respect to the reference line L0 of the movable member 20 (movable base 20a) as an axis are measured by the first displacement meter 41 and the second displacement meter 42 (see FIG. 1). As the positions P11 and P12, the displacement amount of the movable member 20 (movable base 20a) is measured.
The measured values (measurement signals) of the first displacement meter 41 and the second displacement meter 42 are output to the arithmetic unit 15, and the arithmetic unit 15 calculates the diameter D of the track 5 using these measured values.

In the next calculation step St3, the average value of the displacement amounts at the two measurement positions P11 and P12 is obtained in order to obtain the diameter D on the track 5.
In addition, the storage unit of the arithmetic unit 15 stores the measured value and the average value each time measurement is performed, and the size of the work master is already stored. The work master is an inner ring having the same shape as the inner ring 4 to be measured, and has a known track size (diameter). The displacement amount (average value of the two measured values) of the movable base 20a is calculated using the measuring device 10 for this work master, and the result (average value) is stored in the storage unit of the arithmetic unit 15. ing.

  Here, as described above, if the linearity of the movable member 20 with respect to the guide members 31 and 32 becomes unstable, the movable member 20 rotates about the contact position of the third contact 13 with the track 5 and moves. When the member 20 is tilted with respect to the reference line L0, the first displacement meter 41 and the second displacement meter 42 acquire different measurement values as the temporary displacement amount. These temporary displacement amounts do not include the actual displacement amount of the movable member 20 in the direction along the reference line L0, but include the component due to the movable member 20 being tilted. However, since the tilt angle (rotation angle) of the movable member 20 is very small, the components due to the tilt are corrected by averaging the temporary displacement amounts obtained from the first displacement meter 41 and the second displacement meter 42, respectively. The averaged value can be regarded as the displacement amount of the movable member 20 in the direction along the reference line L0.

  In this way, in the calculation step St3, the calculation device 15 obtains the average value of the measurement values of the first displacement meter 41 and the second displacement meter 42. Then, the arithmetic unit 15 uses the average value and the diameter of the track of the work master whose diameter is known to calculate the diameter D of the track 5 of the inner ring 4 that is the actual measurement target. That is, the diameter D of the inner ring 4 on the track 5 is obtained by comparison with the work master.

  The process of obtaining the diameter D on the track 5 may be performed by a method other than the above-described method, for example, using the average value of the measurement values of the first displacement meter 41 and the second displacement meter 42, The diameter D may be calculated by geometrical calculation based on the arrangement of the second contactor 12 and the third contactor 13.

  According to the measuring method performed by the measuring device 10 having the above-described configuration, in order to measure the displacement amount of the movable member 20, two positions that are line-symmetric with respect to the reference line L0 as an axis are measured positions P11, As P12, the displacement amount of the movable member 20 is measured by the first displacement meter 41 and the second displacement meter 42, and the average value of these displacement amounts is calculated. Therefore, for example, the straightness of the movable member 20 with respect to the guide members 31 and 32 is unstable, and the movable member 20 rotates about the contact position of the third contact 13 with respect to the track 5, and the reference line L0. Even if the state is inclined with respect to, the displacement amount of the movable member 20 can be obtained more accurately by averaging the measurement values at the two measurement positions P11 and P12, and the diameter D of the track 5 can be calculated. It is possible to reduce the measurement error as much as possible.

In this way, by averaging the measurement values of the first displacement meter 41 and the second displacement meter 42, the error due to the inclination of the movable member 20 is corrected, and the accuracy of the measurement of the diameter D of the track 5 performed by the computing device 15 is improved. It is possible to improve the stability and repeatability of the measurement.
Then, the measurement accuracy of the diameter D of the inner ring 4 can be improved, and as a result, by using this inner ring 4, it is possible to obtain a ball bearing of a high level with stable clearance (Ra clearance) and contact angle. Become.

  In the above embodiment, the object of measurement is the inner ring 4, but the outer ring 6 may be used. The measuring device in this case is shown in FIGS. 6 and 7. In this measuring device 10, the track 7 formed on the inner peripheral surface of the outer ring 6 is used as a measurement target surface, and the diameter D of the track 7 is measured. In the case of the outer ring 6, the measuring device 10 has a configuration in which the three contacts 11, 12, 13 are brought into contact with the track 7 of the outer ring 6 from the radially inner side, but regarding other configurations and functions, and the measuring method, The configuration is the same as that shown in FIGS.

The embodiments disclosed above are illustrative in all points and not restrictive. That is, the measuring device of the present invention is not limited to the illustrated form, and may have other forms within the scope of the present invention.
The case where the measurement target is the inner ring 4 and the outer ring 6 of the ball bearing has been described, but the present invention is not limited to this, and in order to measure the diameter (inner diameter or outer diameter) of the race ring of another rolling bearing or other cylindrical work. The measuring apparatus and measuring method of the present invention can be applied.

4: Inner ring (cylindrical work) 5: Orbit (measurement surface) 6: Outer ring (cylindrical work)
7: Orbit (measurement target surface) 10: Measuring device 11: First contactor 12: Second contactor 13: Third contactor 15: Arithmetic device 20: Movable member 25: Elastic member 31: Guide member 32: Guide member 41: First displacement meter 42: Second displacement meter D: Diameter L0: Reference line P1, P2: Pressing position P11, P12: Measurement position Q: One point on the reference line

Claims (4)

A first contactor and a second contactor which are arranged in line symmetry with respect to the reference line as an axis, and a third contactor which is located on the reference line, and of a cylindrical work set centered on one point on the reference line. Either one of the outer peripheral surface and the inner peripheral surface, the measurement target surface, by contacting the first contactor, the second contactor and the third contactor, to measure the diameter of the measurement target surface. A measuring device for performing,
A movable member having the third contact mounted thereon,
A first guide member and a second guide member which are arranged line-symmetrically with respect to the reference line and guide the movable member along the reference line;
An elastic member for urging the movable member in a direction parallel to the reference line to press the third contactor against the measurement target surface,
A first displacement meter and a second displacement meter that measure a displacement amount of the movable member at a first measurement position and a second measurement position that are line-symmetrical with respect to the reference line of the movable member as an axis.
An average value of the measured values of the first displacement meter and the second displacement meter is calculated, and a computing device that calculates the diameter based on this average value,
Equipped with
The elastic members are provided on both sides of the reference line in order to press the first pressing position and the second pressing position of the movable member, which are line-symmetrical with respect to the reference line. Including one elastic member and a second elastic member,
The distance in the orthogonal direction from the first guide member to the reference line in the orthogonal direction orthogonal to the reference line and the distance in the orthogonal direction from the second guide member to the reference line are from the first pressing position. The measuring device is larger than the distance in the orthogonal direction to the reference line and the distance in the orthogonal direction from the second pressing position to the reference line . The distance in the orthogonal direction from the first measurement position to the reference line in the orthogonal direction and the distance in the orthogonal direction from the second measurement position to the reference line, the first pressing position from the reference line The measuring device according to claim 1, wherein the distance is greater than the distance in the orthogonal direction and the distance from the second pressing position to the reference line in the orthogonal direction . The measuring device according to claim 1 or 2, wherein the arithmetic unit obtains the diameter of the cylindrical work on the measurement target surface by using the average value and the diameter of the work master on the measurement target surface. Using the measuring device according to any one of claims 1 to 3,
Wherein the first contact and the second contact, and a third contact located on the reference line, one of the outer and inner peripheral surfaces of the cylindrical workpiece to be placed around a single point of the reference line A method for measuring the diameter of the measurement target surface by contacting one measurement target surface,
A movable member carrying the third contactor is guided in a direction parallel to the reference line by the first guide member and the second guide member to bring the third contactor into contact with the measurement target surface, Furthermore, while pressing the third contactor against the measurement target surface, a step of bringing the first contactor and the second contactor into contact with the measurement target surface,
Measuring a displacement amount of the movable member at the first measurement position and the second measurement position ;
A step of obtaining an average value of the displacement amounts at the first measurement position and the second measurement position in order to obtain the diameter of the measurement target surface;
The measuring method equipped with.

Images