JP2009121964A - Movement axis slope detection mechanism and measuring instrument - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve a movement axis slope detection mechanism for detecting a slope of an arm as to a movement mechanism in which the arm is supported by a bearing portion. <P>SOLUTION: The movement axis slope detection mechanism is for detecting a slope of a movement axis of a movement member 1 slidably held on bearing parts 3 and 5. The detection mechanism includes a contact member 12 comprising two contact points 11 making contact with two separate points on a sliding surface of the movement member. and a clinometer 15 provided on the contact member for detecting an angle by which the contact member is displaced from a vertical direction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a moving shaft tilt detection mechanism that detects the tilt of a moving shaft of a moving member that is slidably held on a bearing portion, and a measuring device using the same, and more particularly, a change in the tilt of the moving shaft accompanying the movement of the moving member. The present invention relates to a moving shaft inclination detecting mechanism and a measuring device for detecting a change in inclination of a moving shaft caused by wear of a bearing portion.

  A single-axis moving mechanism and a two-axis or three-axis moving mechanism in combination with the single-axis moving mechanism are widely used. A general uniaxial moving mechanism generally has a mechanism in which a moving member moves with respect to a fixed shaft. However, a mechanism in which a moving shaft supported by a bearing portion moves is also used because of the structure. FIG. 1 is a diagram showing a configuration of a roundness measuring machine in which such a mechanism is used. As shown in the figure, the roundness measuring machine includes a base 51, a turntable 52 provided on the base 51, a column 53 provided on the base 51, and a Z-axis movement that moves vertically along the column 53. A member 54, an arm 55 supported by the Z-axis moving member 54 and moving in the X-axis direction, an attachment portion 56 provided at the tip of the arm 55, and an attachment portion 56 that detects the displacement of the probe 58. Displacement meter 57. The work W is placed on the turntable 52, the Z-axis moving member 54 and the arm 55 are appropriately moved, and the turntable 52 is rotated to rotate with the probe 58 in contact with the surface of the work W. The displacement of the probe 58 is detected.

The Z-axis moving member 54 is engaged with the column 53 by a bearing member, and moves along the sliding surface of the column 53. Further, the Z-axis moving member 54 is provided with a bearing member that supports the sliding surface of the arm 55, and supports the arm 55 so as to be movable. As the arm 55 moves, the rotational moment of the arm 55 with respect to the Z-axis moving member 54 in the plane of FIG. 1 changes. Changes in the Z-axis direction. This change affects measurement of the surface shape of the upper surface of the workpiece W.
Similarly, when the Z-axis moving member 54 moves in the Z-axis direction along the sliding surface of the column 53, the sliding surface of the column 53 changes and affects the measurement of the surface shape of the upper surface of the workpiece W. .

  FIG. 2 is a diagram illustrating a configuration of a support portion of a general moving mechanism used for a support portion of the arm 55 of the Z-axis moving member 54 and the like. As shown in the figure, a lower bearing member 3 is provided on a lower support member 4 provided on the lower side of the housing 2, and a sliding surface of the arm 1 (55) is supported thereon. The upper sliding surface of the arm 1 is pressed against the lower bearing member 3 by an upper bearing member 5 provided on an upper support member 6 provided on the upper side of the housing 2. The upper support member 6 is, for example, a spring member. The arm 1 is movably supported by the lower bearing member 3 and the upper bearing member 5 as described above. Although a drive mechanism for moving the arm 1 is generally provided in the housing, it is not directly related to the invention, so illustration and description are omitted.

  The mechanism for movably supporting the arm (moving member) is not limited to the configuration shown in FIG. 2, and there are various configurations using an air bearing or the like.

  FIG. 3 is a diagram for explaining the influence accompanying the movement of the arm. 3A shows a balanced state in which the central portion of the arm 1 is located in the housing 2 and the rotational moment with respect to the housing 2 is small, and FIG. 3B shows that the arm 1 moves to the end of the movable range. Thus, an unbalanced state in which a large rotational moment with respect to the housing 2 is generated is shown. Reference numeral 7 is a member corresponding to the mounting portion 56 and the displacement meter 57 of FIG. 1 provided at the tip of the arm 1, and 8 is a Z-axis moving member that supports the housing 2 and moves along the vertical axis 9. Indicates.

  In the state shown in FIG. 3A, if the rotational moment of the arm 1 and the member 7 with respect to the housing 2 is small, and the bending of the arm 1 is almost negligible, the displacement of the member 7 in the Z-axis direction is very small. On the other hand, in the state shown in FIG. 3B, the rotational moment of the arm 1 and the member 7 with respect to the housing 2 is large, and a large force is applied to the lower bearing member 3 and the upper bearing member 5 of the housing 2. The arm 1 is tilted by the amount of play of the bearing.

  Further, the bearing is worn as it is used, and play increases accordingly, and the tilt amount of the arm 1 also increases.

  In the roundness measuring machine, the three-dimensional measuring machine, the surface roughness meter, etc., the mechanism shown in FIGS. 2 and 3 is used to support the probe, and the inclination of the arm affects the measurement accuracy. Therefore, Patent Documents 1 to 3 provide an inclinometer for detecting the inclination of the arm or the probe, and improve the measurement accuracy by correcting the assumption that the arm or the probe is inclined by the detected inclination amount. The configuration is described. Patent Document 4 describes an inclinometer that detects the inclination from the vertical direction with high resolution.

Japanese Patent No. 3001989 Patent No. 3099645 Japanese Patent No. 3531882 JP 2003-139530 A

  The inclination of the arm and the probe is not only the play of the bearing portion shown in FIG. 2 that supports the arm, but also the bending of the arm, the play of the bearing portion of the Z-axis moving member 8 of FIG. It is also caused by the inclination of Therefore, it has been difficult to investigate the cause in detail because it is not possible to know how each part is inclined only by detecting the inclination of the arm and the probe with an inclinometer.

  It is thought that it is the play of the bearing portion that supports the arm shown in FIG. 2 that greatly affects the inclination of the arm and the probe. Until now, the measurement of the inclination of the bearing part and the change of the inclination due to play has not been performed.

  An object of the present invention is to realize a moving shaft inclination detecting mechanism that detects an inclination of an arm in a moving mechanism that supports an arm (moving member) at a bearing portion.

  In order to achieve the above object, the movement axis inclination detection mechanism of the present invention makes two contact points of the contact member contact two points away from the sliding surface of the movement member (arm) to incline the inclination of the contact member. Detect with meter.

  In other words, the moving shaft tilt detection mechanism of the present invention is a moving shaft tilt detection mechanism that detects the tilt of the moving shaft of the moving member that is slidably held on the bearing portion, and that is separated from the sliding surface of the moving member. A contact member having two contact points that are in contact with the two points; and an inclinometer provided on the contact member for detecting a displacement angle of the contact member from a vertical direction.

  When the sliding surface of the moving member is supported by the bearing, it is difficult to attach an inclinometer to the sliding surface because it supports movement, and it is difficult to install an inclination detector due to the shape and wiring. Was not done. For this reason, as described in Patent Documents 1 to 3, conventionally, it is conceivable to provide an inclinometer at the tip or the probe that does not interfere with the movement of the moving member, but this is actually difficult due to the weight and the like.

  On the other hand, in the present invention, the two contact points of the contact member are configured to come into contact with the sliding surface of the moving member so that the movement of the moving member is not adversely affected. The moving member is detected by contacting the sliding surface of the moving member so that the tilt of the contacting member directly corresponds to the tilt of the sliding surface of the moving member, and detecting the tilt of the contacting member with an inclinometer provided on the contacting member. The inclination of the sliding surface is detected.

  An arithmetic unit that calculates an inclination change amount that is a difference between displacement angles detected by the inclinometer before and after the moving member (arm) is moved with respect to the bearing portion is further provided to detect a change in inclination accompanying the movement of the moving member. To be configured.

  Further, in order to detect a change with time, an initial inclination change amount storage unit that stores the inclination change amount calculated in the initial state is further provided, and the calculation unit stores the calculated inclination change amount and the initial inclination change amount storage unit. The difference from the initial inclination change amount is calculated. When this difference is large, it is considered that the bearing portion has a large amount of wear.

Further, when the support member (housing) itself supporting the bearing portion is inclined, the moving member (arm) is also inclined. Therefore, in order to calculate and eliminate the influence of the tilt of the support member, a base inclinometer for detecting the displacement angle of the support member from the vertical direction of the bearing portion is further provided, and the difference between the displacement angles detected by the inclinometer and the base inclinometer An arithmetic unit for calculating the reference difference is provided.
Further, an initial reference difference storage unit that stores the reference difference calculated in the initial state is further provided, and the calculation unit calculates a difference between the calculated reference difference and the reference difference in the initial state stored in the initial reference difference storage unit. calculate. Thereby, the change with time of the bearing portion can be detected.
Further, a reference difference before and after the moving member is moved with respect to the bearing portion may be calculated, or a change with time of the change in the reference difference before and after the movement may be detected.

The contact member may be arranged so as to be in contact with two distant points on the upper sliding surface of the moving member, but the two contact points of the contact member are in contact with two distant points on the sliding surface of the moving member. It is conceivable to provide an urging mechanism to make contact with each other.
However, it is required that the two contact points of the contact member do not damage the sliding surface of the moving member even if they come into contact with two distant points on the sliding surface of the moving member. For this reason, it is conceivable to set the contact pressure very small.However, if the contact point is always in contact with the sliding surface, wear of the sliding surface cannot be avoided. A switching mechanism that switches between a state in which the two contact points of the contact member are in contact with two distant points on the sliding surface of the moving member and a state in which they are not in contact is provided, and only when the inclination of the sliding surface of the moving member is detected. It is desirable that the contact point contacts the sliding surface.

  As described above, according to the present invention, in the moving mechanism that supports the sliding surface of the moving member at the bearing portion, the inclination of the sliding surface can be detected, and the change in the tilt accompanying the movement of the moving member is detected. it can. This makes it possible to evaluate the wear and the like of the bearing portion.

  FIG. 4 is a diagram illustrating a configuration of a support portion of the moving mechanism according to the first embodiment of the present invention, and corresponds to FIG.

  As shown in FIG. 4, the movement mechanism of the first embodiment is similar to FIG. 2 in that the housing 2, the lower bearing member 3, the lower support member 4, the upper bearing member 5, and the upper support member 6. And the sliding surface of the arm (moving member) 1 is movably supported. In addition, the mechanism which supports the arm 1 so that a movement is possible is not restricted to the structure of illustration.

  The moving mechanism of the first embodiment further includes a contact member 12 having two contact points 11 that come into contact with two distant points on the sliding surface of the arm 1 and the contact member 12 in contact with the sliding surface of the arm 1. The contact member 12 so as to detect the displacement angle from the vertical direction of the contact member 12 and the holding member 14 provided to hold the biasing member 13 on the housing 2. And an arithmetic unit 16 for calculating the detection result of the inclinometer 15. The calculation unit 16 includes an initial value storage unit 17 configured by a computer or the like and configured by a non-volatile memory that stores calculation results. The biasing member 13 is a spring, for example. The inclinometer 15 is an electronic level that detects absolute horizontal with respect to the direction of gravity (vertical direction), and has a configuration as described in Patent Document 4, for example.

  Since the two contact points 11 provided on the contact member 12 come into contact with two points away from the sliding surface of the arm 1, the contact member 12 has an inclination corresponding to the inclination of the sliding surface of the arm 1. If the inclination from the vertical direction is detected by the inclinometer 15 attached to the contact member 12, the inclination of the sliding surface of the arm 1 can be detected. The contact member 12 is configured to contact a predetermined position on the sliding surface of the arm 1 by a position regulating member (not shown).

  FIG. 5 shows a process of calculating a difference in inclination of the arm 1 at the support portion when the arm 1 moves as shown in FIGS. 3A and 3B in the moving mechanism of the first embodiment. It is a flowchart to show.

  In step 101, as shown in FIG. 3A, the arm 1 moves to the shortest position on the rightmost side.

  In step 102, the output of the inclinometer 15 is read as detection data D1.

  In step 103, as shown in FIG. 3B, the arm 1 moves to the farthest position located on the leftmost side.

  In step 104, the output of the inclinometer 15 is read as detection data D2.

  In step 105, a difference D1-D2 between D1 and D2 is calculated. This is the difference in inclination of the arm 1 between the shortest position and the farthest position.

  In step 106, it is determined whether the absolute value of the difference D1-D2 is greater than a predetermined threshold T. If it is smaller, the process proceeds to step 107, and if larger, the process proceeds to step 108.

  In step 107, since the absolute value of the difference D1-D2 is smaller than the predetermined threshold T, the change in the tilt accompanying the movement of the arm 1 is within an allowable range and is normal. Accordingly, normal operation is started, and notification is made that it is normal if necessary.

  In step 108, since the absolute value of the difference D1-D2 is larger than the predetermined threshold T, the change in the tilt accompanying the movement of the arm 1 exceeds the allowable range, and there is some cause such as large wear of the bearing portion. Since it is thought that there is, it is notified that it is abnormal.

  It is also possible to perform correction by calculating an error due to the inclination of the tip of the arm 1 using the calculated difference D1-D2. Further, when an inclinometer is provided at the tip of the arm 1, the deflection of the arm 1 can be detected by calculating a difference from the detection data.

  FIG. 6 is a flowchart showing another process in the first embodiment. In this process, the change with time of the change in the inclination of the arm 1 is calculated.

  Step 201 to step 203 are performed at the time of initialization when the moving mechanism is installed.

  In step 201, the output of the inclinometer 15 at the shortest position of the arm 1 is read as detection data D1.

  In step 202, the output of the inclinometer 15 at the farthest position of the arm 1 is read as detection data D2.

  In step 203, a difference DX between D1 and D2 is calculated and stored in the initial value storage unit 17. Therefore, the difference DX is kept permanently.

  Subsequent steps are performed periodically or as needed according to the usage situation.

  In step 204, the output of the inclinometer 15 at the shortest position of the arm 1 is read as detection data D1 '.

  In step 205, the output of the inclinometer 15 at the farthest position of the arm 1 is read as detection data D2 '.

  In step 206, a difference DX 'between D1' and D2 'is calculated.

  In step 207, it is determined whether or not the absolute value of the difference DX and the difference DX 'is larger than a predetermined time threshold value T1, the process proceeds to step 208 if it is smaller, and the process proceeds to step 209 if it is larger.

  In step 208, since the absolute value of the difference DX and the difference DX ′ is smaller than the elapsed time threshold T1, it is normal because the change from the initial state is small and the wear of the bearing portion is considered to be small, and normal operation is started. To do.

  In step 209, since the absolute value of the difference DX and the difference DX 'is larger than the temporal threshold value T1, it is considered that the wear and the like of the bearing portion is large.

  In the first embodiment, the configuration of the arm 1 including the change in the inclination of the bearing portion of the Z-axis moving member 8 and the column (vertical axis) 9 due to the change in the rotational moment of the portion including the arm 1 is configured as shown in FIG. An inclination change is detected. With this, it is not possible to detect only a change in inclination due to the bearing portion of the housing 2. Therefore, in the second embodiment of the present invention, only a change in inclination due to the bearing portion of the housing 2 can be detected.

  FIG. 7 is a diagram illustrating the configuration of the support portion of the moving mechanism according to the second embodiment of the present invention, and is different from the first embodiment in that a base inclinometer 18 is provided in the housing 2. The part is the same as in the first embodiment. An arithmetic unit 16 is also provided but is not shown. Here, the inclinometer 15 corresponds to the inclinometer A, and the inclinometer 18 corresponds to the inclinometer B.

  FIG. 8 is a flowchart illustrating a process for detecting a change with time in the inclination of the bearing portion in the moving mechanism according to the second embodiment.

  In step 301, the arm 1 is moved to a predetermined position.

  In step 302, the output of the inclinometer A15 is read as detection data DA.

  In step 303, the output of the inclinometer B18 is read as the detection data DB.

  In step 304, DA-DB = DY (reference difference) is calculated and stored in the initial value storage unit. Therefore, the difference DX is kept permanently. Subsequent steps are performed periodically or as needed according to the usage situation.

In step 305, the arm 1 is moved to the same predetermined position as in step 301.
In step 306, the output of the inclinometer A15 is read as detection data DA ′.
In step 307, the output of the inclinometer B18 is read as detection data DB ′.
In step 308, a difference DY ′ (reference difference) between DA ′ and DB ′ is calculated.

  In step 309, it is determined whether the absolute value of the difference between the difference DY and the difference DY ′ (amount of change in the reference difference with time) is greater than a predetermined threshold T 2.

  In step 310, since the absolute value of the difference between the difference DY and the difference DY ′ is smaller than the threshold T2, it is normal because the change from the initial state is small and the wear of the bearing portion is considered to be small, and normal operation is started. .

  In step 311, since the absolute values of the difference DY and the difference DY ′ are larger than the threshold value T <b> 2, it is considered that the wear and the like of the bearing portion is large, so that the abnormality is notified.

  FIG. 9 shows a process of calculating a difference in inclination of the arm 1 in the support portion when the arm 1 moves as shown in FIGS. 3A and 3B in the moving mechanism of the second embodiment. It is a flowchart to show.

In step 401, the arm 1 is moved to the shortest position.
In step 402, the output of the inclinometer A15 is read as detection data D1A.
In step 403, the output of the inclinometer B18 is read as detection data D1B.
In step 404, D1A−D1B = D1X (reference difference) is calculated and stored.

In step 405, the arm 1 is moved to the farthest position.
In step 406, the output of the inclinometer A15 is read as detection data D2A.
In step 407, the output of the inclinometer B18 is read as detection data D2B.
In step 408, D2A−D2B = D2X (reference difference) is calculated and stored.

  In step 409, it is determined whether or not the absolute value of the difference between D1X and D2X (the movement change amount of the reference difference) is larger than a predetermined threshold T3. If it is smaller, the process proceeds to step 410, and if larger, the process proceeds to step 411.

  In step 410, since the absolute value of the difference between D1X and D2X is smaller than a predetermined threshold T3, the bearing portion of the support portion of the moving mechanism is normal and normal operation is started.

  In step 411, since the absolute value of the difference between D1X and D2X is greater than a predetermined threshold value T3, it is considered that the wear of the bearing portion of the support portion of the moving mechanism is large, and an abnormality is notified.

  FIG. 10 is a diagram illustrating the change over time of the movement change amount of the reference difference of the arm 1 in the support portion when the arm 1 moves as shown in FIGS. 3A and 3B in the moving mechanism of the second embodiment. It is a flowchart which shows the process which calculates a change.

In step 501, as shown in FIG. 3A, the arm 1 moves to the shortest position located on the rightmost side.
In step 502, D1X is calculated by performing steps 402 to 404 in FIG.

In step 503, as shown in FIG. 3B, the arm 1 moves to the farthest position located on the leftmost side.
In step 504, steps 406 to 408 in FIG. 9 are performed to calculate D2X.
In step 505, D1X−D2X = DY is calculated and stored in the initial value storage unit. Therefore, the difference DY is kept permanently. Subsequent steps are performed periodically or as needed according to the usage situation.

In step 506, the arm 1 is moved to the shortest position.
In step 507, steps 402 to 404 in FIG. 9 are performed to calculate D1X, which is defined as D1X ′.

In step 508, the arm 1 is moved to the farthest position.
In step 509, steps 406 to 408 in FIG. 9 are performed to calculate D2X, which is defined as D2X ′.
In step 510, D1X′−D2X ′ = DY ′ is calculated.

  In step 511, it is determined whether or not the absolute value of the difference between DY and DY ′ is greater than a predetermined threshold T 4. If smaller, the process proceeds to step 512, and if larger, the process proceeds to step 513.

  In step 512, since the absolute value of the difference between DY and DY 'is smaller than a predetermined threshold value T4, the bearing portion of the support portion of the moving mechanism is normal and normal operation is started.

  In step 513, since the absolute value of the difference between DY and DY 'is larger than a predetermined threshold value T4, it is considered that the wear of the bearing portion of the support portion of the moving mechanism is large, and an abnormality is notified.

  In the first and second embodiments, the two contact points 11 provided on the contact member 12 are configured to always contact the sliding surface of the arm 1. For this reason, the contact point 11 may be worn out or the sliding surface of the arm 1 may be damaged. In the third embodiment, this problem is solved.

  FIG. 11 is a diagram illustrating a configuration of a moving mechanism according to a third embodiment of the present invention, where (A) shows a non-contact state and (B) shows a contact state.

  As shown in FIG. 11, the moving mechanism of the third embodiment is similar to the first embodiment in that the housing 2, the lower bearing member 3, the lower support member 4, the upper bearing member 5, and the upper support And a sliding surface of the arm (moving member) 1 is movably supported. The moving mechanism of the third embodiment further includes a contact member 12 having two contact points 11 that come into contact with two distant points on the sliding surface of the arm 1, and the contact member 12 contacts the sliding surface of the arm 1. The urging member 13 that urges the urging member 13, the urging support member 21 that supports the urging member 13, the rotating shaft 22, the rotating shaft 24 provided in the housing 2, and the urging supporting member 21. An engagement member 23 that engages the rotation shaft 22 and the rotation shaft 24, an actuator 25 that is provided on the housing 2 and pushes the engagement member 23 upward, and an inclinometer 26 that is provided on the contact member 12. . A calculation unit for calculating the detection result of the inclinometer 26 is also provided, but the illustration is omitted. The actuator 25 is composed of a piezo element, for example. Also in this case, each member is configured so that the contact point 11 of the contact member 12 contacts a predetermined position on the sliding surface of the arm 1 by a position regulating member (not shown), and the contact point 11 is also retracted. Although the interval between the sliding surfaces of the arm 1 and the arm 1 is small, the arm 1 is configured so as not to contact with certainty.

  In a state where no voltage is applied to the actuator 25, as shown in FIG. 11A, the engaging member 23 is inclined downward, the urging support member 21 is lowered, and the contact member 12 is 2 The individual contact points 11 are positioned so as not to contact the sliding surface of the arm 1.

  When a voltage is applied to the actuator 25, as shown in FIG. 11B, the engaging member 23 tilts upward, the urging support member 21 rises, and the contact member 12 has two contact points 11 at the arm. 1 is in contact with the sliding surface. The two contact points 11 are brought into contact with the sliding surface of the arm 1 with a predetermined pressure by the biasing member 13. As a result, the contact member 12 has an inclination corresponding to the inclination of the sliding surface of the arm 1. If the inclination from the vertical direction is detected by the inclinometer 26 attached to the contact member 12, the sliding of the arm 1 is performed. The inclination of the surface can be detected.

  When the inclination of the arm 1 is detected in the state shown in FIG. 11B and the detection of the inclination is completed, the arm 1 is moved in the state shown in FIG. Thereby, there is no possibility that the contact point 11 is worn out or the sliding surface of the arm 1 is damaged.

  The configuration of the moving mechanism of the third embodiment is also applicable to the first and second embodiments.

  In the first and second embodiments, the two contact points 11 of the contact member 12 are configured to come into contact with two points separated from the lower sliding surface of the arm 1 by the biasing member 13. As shown in FIG. 12, the contact member 12 may be configured to contact the upper sliding surface of the arm 1. Also in this case, the two contact points 11 of the contact member 12 are configured to contact a predetermined position of the upper sliding surface of the arm 1 by a position regulating member (not shown). In this case, the contact member 12 may be brought into contact with its own weight including the inclinometer 15. However, when the contact pressure becomes too high, a mechanism for reducing the contact pressure may be provided. Also in this case, a retracting mechanism as in the third embodiment is provided, and the two contact points 11 of the contact member 12 are configured to contact the upper sliding surface of the arm 1 only at the time of detection. Is also possible.

By using the moving mechanism of the first to third embodiments, the deviation of the tip position of the moving member (arm) is calculated and the deviation is corrected, thereby improving the measurement accuracy of the measuring device or processing. It is possible to improve the processing accuracy of the apparatus.
13 shows the roundness measurement in which the configuration of the moving mechanism of the first embodiment is applied to the portion of the Z-axis moving member 54 of the roundness measuring machine shown in FIG. It is a figure which shows schematic structure of a machine.
As shown in FIG. 13, a control / data processing unit 61 is provided in the roundness measuring machine. Reference numeral 62 indicates a sensor for detecting the movement positions of the column 53, the Z-axis moving member 54, and the arm 55 provided in the roundness measuring machine.

  The control / data processing unit 61 controls the drive mechanism of each part of the roundness measuring machine, detects the displacement of the probe 58 from the displacement meter 57, and the rotational position signal output from the rotational position sensor of the turntable 52. The position of the probe 58 is calculated based on the column 53 output from the sensor 62, the Z-axis moving member 54, and the movement position signals of the Z-axis moving member 54 and the arm 55. Here, the control / data processing unit 61 corrects the calculated position of the probe 58 based on the tilt signal from the calculation unit 16 of the moving mechanism provided in the Z-axis moving member 54. The correction is performed, for example, as a positional deviation in the Z-axis direction (height direction) by multiplying the horizontal distance from the Z-axis moving member 54 of the arm 55 to the probe 58 by the tilt amount. In some cases, the bending of the arm 55 may be taken into consideration. Further, when the amount of inclination changes depending on the movement position of the arm 55, correction is made in advance according to the movement position. Various correction methods are possible.

FIG. 14 is a flowchart showing the correction processing of the control / data processing unit 61.
In step 601, as shown in FIG. 3A, the arm 1 moves to the shortest position located on the rightmost side.
In step 602, the output of the inclinometer 15 is read as detection data D1 via the calculation unit 16.
In step 603, as shown in FIG. 3B, the arm 1 moves to the farthest position located on the leftmost side.
In step 604, the output of the inclinometer 15 is read as detection data D2 via the calculation unit 16.
In step 605, a difference D1-D2 between D1 and D2 is calculated.

In step 606, it is determined whether the absolute value of the difference D1-D2 is greater than a predetermined threshold value T5. If smaller, the process proceeds to step 608, and if larger, the process proceeds to step 607. The threshold value T5 may be the same as or different from T in FIG.
In step 607, since the absolute value of the difference D1-D2 is larger than the predetermined threshold value T5, it exceeds the allowable allowable range, and it is considered that there is some cause such as large wear of the bearing portion. Notify that.

In step 608, it is determined whether the absolute value of the difference D1-D2 is greater than a predetermined threshold T6. If smaller, the process proceeds to step 609, and if larger, the process proceeds to step 610.
In step 608, since the absolute value of the difference D1-D2 is smaller than the predetermined threshold value T6, the change in the tilt accompanying the movement of the arm 1 does not need to be corrected, so the normal operation is started as it is.

In step 610, an equation or a lookup table for calculating the positional deviation in the height direction of the probe 58 according to the moving position of the arm is created from the difference D1-D2.
In step 611, the measurement operation is started. In the calculation of the measurement value, the positional deviation of the probe 58 corresponding to the arm movement position is corrected based on the positional deviation calculation formula obtained in step 610.

  As mentioned above, although embodiment of this invention was described, it cannot be overemphasized that various modifications are possible. For example, in the first to third embodiments, a change in the inclination of the arm moving in the horizontal direction with respect to the horizontal plane is detected, but the present invention can also be applied to a moving mechanism in which the arm moves in the vertical direction. In some cases, the direction of the inclinometer attached to the contact member is changed by 90 degrees.

  The present invention is applicable to any moving mechanism as long as the moving member moves in the center of gravity with respect to the bearing portion (a change in rotational moment occurs).

It is a figure which shows the structure of a roundness measuring device. It is a figure which shows the structure of the conventional moving mechanism to which the arm supported by the bearing part moves. It is a figure explaining the inclination change accompanying the arm movement in the conventional moving mechanism. It is a figure which shows the structure of the moving mechanism of 1st Embodiment of this invention. It is a flowchart which shows the process which detects the inclination change accompanying the movement of an arm in the moving mechanism of 1st Embodiment. It is a flowchart which shows the process which detects the time-dependent change of the inclination change accompanying the movement of an arm in the moving mechanism of 1st Embodiment. It is a figure which shows the structure of the moving mechanism of 2nd Embodiment of this invention. It is a flowchart which shows the process which detects the time-dependent change of inclination in the moving mechanism of 2nd Embodiment. It is a flowchart which shows the process which detects the inclination change accompanying the movement of an arm in the moving mechanism of 2nd Embodiment. It is a flowchart which shows the process which detects the time-dependent change of the inclination change accompanying the movement of an arm in the moving mechanism of 2nd Embodiment. It is a figure which shows the structure of the moving mechanism of 3rd Embodiment of this invention. It is a figure which shows the structure of the modification of a moving mechanism. It is a figure which shows the structure at the time of applying the moving mechanism of embodiment to a roundness measuring device. It is a flowchart which shows the correction | amendment process in the roundness measuring device to which the moving mechanism of embodiment is applied.

Explanation of symbols

1 Moving member (arm)
2 Housing 3 Lower bearing portion 4 Lower support member 5 Upper bearing portion 6 Upper support member 11 Contact point 12 Contact member 13 Biasing member 15 Inclinometer

Claims (11)

A moving shaft inclination detecting mechanism for detecting an inclination of a moving shaft of a moving member slidably held in a bearing portion provided in a support member,
A contact member having two contact points in contact with two distant points on the sliding surface of the moving member;
An inclinometer that is provided on the contact member and detects a displacement angle of the contact member from a vertical direction.   The movement axis inclination detection mechanism according to claim 1, further comprising an urging member that urges the contact member so as to contact two points on the sliding surface of the moving member.   The biasing member further includes a switching mechanism that switches between a state in which the two contact points of the contact member are in contact with two points away from a sliding surface of the moving member and a state in which the two contact points are not in contact with each other. The moving axis inclination detection mechanism described.   The movement axis inclination detection mechanism according to any one of claims 1 to 3, further comprising a base inclinometer that detects a displacement angle of a support member of the bearing portion from a vertical direction.   The movement axis inclination detection mechanism according to claim 1, further comprising a calculation unit that calculates an inclination change amount that is a difference between the displacement angles detected by the inclinometer before and after the movement member is moved relative to the bearing part. . An initial inclination change amount storage unit for storing the inclination change amount calculated in the initial state;
The moving axis inclination detection mechanism according to claim 5, wherein the calculation unit calculates a difference between the calculated inclination change amount and the initial inclination change amount stored in the initial inclination change storage unit.   The movement axis inclination detection mechanism according to claim 4, further comprising a calculation unit that calculates a reference difference that is a difference between the displacement angles detected by the inclinometer and the base inclinometer. An initial reference difference storage unit that stores the reference difference calculated in the initial state;
The movement axis inclination detection mechanism according to claim 7, wherein the calculation unit calculates a difference between the calculated reference difference and the reference difference in an initial state stored in the initial reference difference storage unit.   The calculation unit calculates and stores a pre-movement reference difference, which is the reference difference in a state before moving the moving member relative to the bearing unit, and moves the moving member relative to the bearing unit. The movement axis inclination detection mechanism according to claim 7, wherein a movement reference difference change amount, which is a difference from the pre-movement reference difference, is calculated by calculating a reference difference after movement that is the reference difference in the state. An initial reference difference change amount storage unit that stores the movement reference difference change amount calculated in the initial state;
The movement axis according to claim 9, wherein the calculation unit calculates a difference between the calculated movement reference difference change amount and the movement reference difference change amount in an initial state stored in the initial reference difference change storage unit. Tilt detection mechanism. A moving member;
A probe provided at the tip of the moving member for detecting the surface position of the workpiece;
A sliding holding portion having a bearing portion for holding the moving member in a slidable manner;
A drive unit for moving the moving member;
In a measurement apparatus comprising: a control / data processing unit that performs control of each unit including the driving unit and calculates detection data of the probe to calculate a surface shape of the workpiece.
The moving shaft inclination detecting mechanism according to any one of claims 1 to 4, further comprising a moving shaft inclination detecting mechanism that is provided in the sliding holding portion and detects an inclination of a moving axis of the moving member.
The control / data processing unit calculates a positional deviation of the probe according to the inclination detected by the movement axis inclination detecting mechanism, and corrects the detection data based on the calculated positional deviation to correct the surface shape of the workpiece. Measuring device that calculates

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