JP2016211985A - Circularity measuring apparatus and measurement object fixture of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circularity measuring apparatus capable of measuring circularity of a spherical measurement object with high accuracy, and a measurement object fixture of the same.SOLUTION: When circularity of a spherical work W is measured, a spherical work fixture 50 is installed on the mount base 12 of a circularity measuring apparatus and the work W is mounted on a work mounting unit 100 on the upper surface of the spherical work fixture 50. The work mounting unit 100 is provided with support balls for supporting the work W at three points and the work W is coupled to a weight member 84 via a suction pad 96 so that the work W does not move by measurement pressure.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a roundness measuring apparatus and a measuring object fixing jig thereof, and more particularly to a roundness measuring apparatus capable of measuring the roundness of a spherical measuring object (work) with high accuracy and the measuring object thereof. The present invention relates to an object fixing jig.

  When measuring the roundness of a spherical workpiece with a roundness measuring device, the position of the bus of the workpiece is usually measured. Therefore, it is necessary to fix the workpiece at a portion other than the busbar.

  Japanese Patent Application Laid-Open No. 2004-133620 discloses a technique for enabling a roundness measurement apparatus to measure a roundness of a spherical workpiece by installing a test sphere holding means for holding a spherical workpiece on a rotary table. . According to this, it is comprised from the installation stand installed on a turntable, and the rotation arm extended diagonally upward from the installation stand, Comprising: The rotation arm holding a spherical workpiece | work in a front-end | tip part.

JP 2012-63338 A

  However, in the specimen holding means described in Patent Document 1, the workpiece is supported only by the arm extending obliquely upward, and the measurement pressure (measurement force) from the measurement probe when the measurement probe is brought into contact with the workpiece. ) Is added to the workpiece, there is a possibility that the position of the workpiece with respect to the test sphere holding means will fluctuate, resulting in a decrease in measurement accuracy.

  The present invention has been made in view of such circumstances, and provides a roundness measuring device and a measuring object fixing jig capable of measuring the roundness of a spherical measuring object with high accuracy. For the purpose.

  In order to achieve the above object, a roundness measuring apparatus according to one aspect of the present invention is configured to move a measuring element relative to a spherical measuring object while moving the measuring element in contact with the position of the generating line. A roundness measuring apparatus for measuring the roundness of a measurement object, the first direction being a direction perpendicular to a plane including a generatrix of the measurement object and a first direction and a second direction that are opposite to each other A regulating member that contacts the range of the hemisphere on the side and regulates the movement of the measurement object in the first direction, and is connected to the measurement object in a range on the first direction side of the contact position of the regulation member. A connecting member; a connecting unit that removably connects the connecting member to the measurement object; and a load unit that applies a force in the first direction to the measurement object via the connection member.

  According to this aspect, the spherical measurement object is pressed against the regulating member by the force in the first direction applied via the connecting member by the load means, and the measurement pressure from the probe is measured even when the measurement object is light. Regardless of the position variation is suppressed. Therefore, highly accurate measurement is possible.

  In the roundness measuring apparatus according to another aspect of the present invention, the connecting member is a suction pad, and the connecting means connects the negative pressure generating means for generating a negative pressure, and the suction pad and the negative pressure generating means. It can be set as the aspect which consists of piping.

  According to this aspect, it is possible to easily attach and detach the load means that applies a force to the regulating member with respect to the measurement object.

  In the roundness measuring apparatus according to still another aspect of the present invention, the pipe is disposed between the connection part that removably connects the negative pressure generating means, the suction pad, and the connection part, and opens and closes the pipe line. It can be set as the aspect provided with the valve and the tank which maintains the negative pressure arrange | positioned between the suction pad and the valve | bulb.

  According to this aspect, by closing the valve after setting the tank to a negative pressure, the connecting member can be connected to the object to be measured even if the negative pressure generating means is removed from the pipe, and the force by the load means can be maintained. It can be added to the measurement object. Therefore, the roundness can be measured by rotating the measurement object together with the regulating member, the connecting member, and the load means without being obstructed by the negative pressure generating means.

  In the roundness measuring apparatus according to still another aspect of the present invention, the load means may be a weight member connected to the connecting member.

  According to this aspect, gravity according to the weight of the weight member can be added to the measurement object.

  In the roundness measuring apparatus according to still another aspect of the present invention, the regulating member is a fulcrum member that contacts at three points around an axis parallel to the first direction through the center of the measurement object. be able to.

  According to this aspect, the measurement object can be stably fixed at a position determined by three points.

  In the roundness measuring apparatus according to still another aspect of the present invention, the bus line may be a contour curve in a horizontal section passing through the center of the measurement object, and the first direction may be a vertically downward direction. .

  In order to achieve the above object, the measuring object fixing jig of the roundness measuring apparatus according to another aspect of the present invention is detachably attached to the roundness measuring apparatus to fix the spherical measuring object. A measuring object fixing jig, and a circularity of the measuring object is moved relative to the measuring object while moving the measuring element of the roundness measuring device in contact with the position of the generating line. A measuring object fixing jig of a roundness measuring apparatus for measuring a degree, wherein the measuring object fixing jig is a direction perpendicular to a plane including a generatrix of the measuring object, and is one of the opposite first and second directions. A regulating member that contacts the range of the hemisphere on the first direction side and regulates the movement of the measurement object to the first direction side; and a range on the first direction side relative to the contact position of the regulating member with respect to the measurement object A coupling member to be coupled and a coupling for detachably coupling the coupling member to the measurement object Comprising the stage, and a load means for applying a force in the first direction via the connecting member to the object of measurement, the.

  According to this aspect, the spherical measurement object is pressed against the regulating member by the force in the first direction applied via the connecting member by the load means, and the measurement pressure from the probe is measured even when the measurement object is light. Regardless of the position variation is suppressed. Therefore, highly accurate measurement is possible.

  In the measuring object fixing jig of the roundness measuring apparatus according to another aspect of the present invention, the connecting member is a suction pad, and the connecting means includes a negative pressure generating means for generating a negative pressure, a suction pad and a negative pad. It can be set as the aspect which consists of piping which connects a pressure generation means.

  According to this aspect, it is possible to easily attach and detach the load means that applies a force to the regulating member with respect to the measurement object.

  In the measuring object fixing jig of the roundness measuring device according to still another aspect of the present invention, the pipe is disposed between the connection portion that removably connects the negative pressure generating means, and the suction pad and the connection portion. And a tank that opens and closes the conduit and a tank that maintains a negative pressure disposed between the suction pad and the valve.

  According to this aspect, by closing the valve after setting the tank to a negative pressure, the connecting member can be connected to the object to be measured even if the negative pressure generating means is removed from the pipe, and the force by the load means can be maintained. It can be added to the measurement object. Therefore, the roundness can be measured by rotating the measurement object together with the regulating member, the connecting member, and the load means without being obstructed by the negative pressure generating means.

  In the measuring object fixing jig of the roundness measuring apparatus according to still another aspect of the present invention, the load means may be a weight member connected to the connecting member.

  According to this aspect, gravity according to the weight of the weight member can be added to the measurement object.

  In the measuring object fixing jig of the roundness measuring device according to still another aspect of the present invention, the regulating member contacts at three points around an axis parallel to the first direction through the center of the measuring object. It can be set as the aspect which is a fulcrum member.

  According to this aspect, the measurement object can be stably fixed at a position determined by three points.

  In the measuring object fixing jig of the roundness measuring device according to still another aspect of the present invention, the bus is a contour curve in a horizontal section passing through the center of the measuring object, and the first direction is a vertically downward direction. It can be set as a certain aspect.

  In the measuring object fixing jig of the roundness measuring apparatus according to still another aspect of the present invention, the roundness measuring apparatus is a mounting table on which a cylindrical or columnar measuring object is placed. It can be set as the aspect with which a control member, a connection member, and a load means are detachably mounted | worn with respect to the mounting base.

  According to the present invention, the roundness of a spherical workpiece can be measured with high accuracy.

The perspective view which showed the whole structure of the roundness measuring apparatus based on this invention Partial sectional view showing the spherical workpiece fixing jig in the state of FIG. 1 from the horizontal direction. FIG. 2 is a cross-sectional view of the spherical workpiece fixing jig in the state shown in FIG. FIG. 1 is a plan view showing a spherical workpiece fixing jig in the state of FIG. 1 from above. Sectional drawing which expanded and showed the workpiece | work mounting part in FIG. Plan view showing the state of the spherical workpiece fixing jig during measurement Image diagram showing the workpiece placement part in the spherical workpiece fixture from above Image drawing showing the workpiece placement part in the spherical workpiece fixture from the side FIG. 9 is an image view showing a workpiece mounting portion in a spherical workpiece fixing jig from above, and showing a state in which the measuring element is in contact with the workpiece at a position on the opposite side of FIGS. 7 and 8. FIG. 9 is an image view showing a workpiece placement portion in a spherical workpiece fixing jig from the side, and shows a state in which the measuring element is in contact with the workpiece at a position opposite to those in FIGS. 7 and 8. It is sectional drawing which showed the spherical workpiece fixing jig of other embodiment, and is a figure corresponding to FIG.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a perspective view showing the overall configuration of a roundness measuring apparatus according to the present invention.

  In order to measure the roundness of a spherical measuring object (work W) with respect to a well-known and existing roundness measuring device for measuring roundness, a roundness measuring device 1 shown in FIG. A spherical workpiece fixing jig 50 is attached as a detachable measuring object fixing jig.

  First, a configuration part known as an existing roundness measuring device will be briefly described.

  In the roundness measuring apparatus 1, a base-like base 10 that supports the entire apparatus is disposed at the lower end, and the upper surface of the base 10 is in the direction around the rotation axis (θ axis) along the vertical direction (vertical direction). A stage 12 that is rotatable is provided. In the drawing, the vertical direction is represented as the Z-axis direction.

  A spherical workpiece fixing jig 50, which will be described later in detail, simplified in the drawing, is detachably fixed to the upper surface of the mounting table 12, and becomes an object to be measured on the upper surface of the spherical workpiece fixing jig 50. A spherical workpiece W is supported. Further, the workpiece W is supported so that the center thereof is on the rotation axis (θ axis) of the mounting table 12.

  Inside the base 10, a rotation drive unit 11 that includes a motor or the like coupled to the mounting table 12 and that rotationally drives the mounting table 12 is provided.

  By this rotation driving unit 11, the spherical workpiece fixing jig 50 and the workpiece W fixed to the mounting table 12 rotate together with the mounting table 12 in the direction around the θ axis.

  The stage 12 may be manually rotated. Further, the mounting table 12 may be movable in the direction perpendicular to the θ axis and in the left-right direction and the front-rear direction orthogonal to each other by rotating the knob.

  On the upper surface side of the base 10, a detector 24 (measurement probe) is supported via a detector support mechanism 13 having a column 14, a carriage 16, a radial movement arm 18, a turning arm 20, and a detector holder 22.

  The detector 24 is provided, for example, in a measuring element 24B (stylus) extending in a rod shape from the lower end of the cylindrical detector main body 24A, and inside the detector main body 24A, and detects a displacement amount of the measuring element 24B by an operating transformer or the like. And a displacement detector (not shown) for outputting as an electrical signal (detection signal).

  The measuring element 24B is supported by the detector main body 24A so that the axis line of the measuring element 24B can be displaced in a direction (displacement direction) perpendicular to the axis line in one plane, and one direction (attachment) of the displacement direction is attached. Is biased by a spring or the like.

  At the time of measurement, the tip portion (tip sphere) of the probe 24B is pressed against the peripheral surface of the workpiece W in the biasing direction, and the contact is maintained. Then, along with the rotation of the workpiece W around the θ axis by the rotation drive unit 11, a detection signal from the detector 24 indicating the amount of displacement of the probe 24B is read by an arithmetic processing device (not shown), and true based on the detection signal. Calculation of circularity and the like is performed.

  In the present embodiment, the tip of the measuring element 24B is brought into contact with the position of the bus bar of the spherical workpiece W, that is, the position of the contour curve of the workpiece W in the horizontal section passing through the center of the workpiece W, and the bus bar is in contact with the bus bar. The roundness is measured by moving the tracing stylus 24B along.

  The detector support mechanism 13 will be described. On the upper surface of the base 10, a column 14 extending in the vertical direction is erected on the right side of the mounting table 12. The column 14 supports a carriage 16 that can move in the vertical direction along the column 14. The carriage 16 moves up and down by, for example, driving of a motor, but may be moved manually by rotating a knob or the like.

  By this vertical movement mechanism of the carriage 16, the detector support mechanism 13 supports the detector 24 so that the vertical position can be changed.

  A radial movement arm 18 extending in the radial direction is supported on the carriage 16 so as to be movable in the radial direction. The radial movement arm 18 moves in the radial direction by, for example, driving of a motor, but may be manually moved by rotating a knob or the like.

  The detector support mechanism 13 supports the position of the detector 24 in the radial direction so as to be changeable by the radial movement mechanism of the radial movement arm 18.

  The radial direction indicates the radial direction (R-axis direction) centered on the rotation axis (θ-axis) of the mounting table 12, and the direction in which the radial movement arm 18 moves is the left-right direction (X-axis direction). A direction perpendicular to the Z-axis direction and the X-axis direction is defined as a front-rear direction (Y-axis direction).

  One end (base end) of the swivel arm 20 is connected to the end of the left side (the table 12 side) of the radial movement arm 18 so as to be capable of swiveling around a swivel axis along the radial direction. The turning arm 20 is fixed to the radial movement arm 18 by a screw. By loosening the screw by rotating the knob 30, the turning arm 20 can turn around the turning axis, and the direction of the turning arm 20 can be changed. It becomes possible.

  By this turning mechanism of the turning arm 20, the detector support mechanism 13 supports the detector 24 so that the turning angle around the turning axis along the radial direction can be changed.

  A proximal end portion of the detector holder 22 extending in the radial direction (left-right direction) is fixed to the distal end portion of the swivel arm 20.

  A detector 24 is detachably attached to the tip of the detector holder 22 by rotating the knob 32.

  The detector holder 22 is such that the distal end side of the detector 24 (side on which the measuring element 24B is provided) is directed to the axis of the turning axis of the turning arm 20, and the axis of the detector body 24A is the turning arm. The proximal end side of the detector 24 is fixed so as to be parallel to the 20 axis.

  The detector holder 22 can be fixed by changing the mounting angle of the detector 24, that is, the rotation angle around the axis of the detector main body 24A. The displacement direction and the urging direction of the probe 24B can be adjusted by a mechanism for adjusting the mounting angle of the detector 24 in the detector holder 22.

  The roundness measuring device 1 in FIG. 1 is a workpiece rotation type measuring device in which the detector 24 relatively rotates around the workpiece W in the circumferential direction when the workpiece W rotates. The detector 24 may be a detector-rotating type measuring device that rotates around the workpiece W.

  2, FIG. 3, and FIG. 4 are partial sectional views showing the spherical workpiece fixing jig 50 in the state of FIG. It is sectional drawing shown from the horizontal direction, and the top view shown from upper direction.

  As shown in these drawings, the spherical workpiece fixing jig 50 has a disk-like base member 52 at the bottom, and the base member 52 is attached to and detached from the upper surface of the mounting table 12 with screws 54 (see FIG. 4). Fixed as possible.

  Thereby, the spherical workpiece fixing jig 50 can be easily attached to and detached from the existing roundness measuring device, and the roundness of the spherical workpiece W is measured using the existing roundness measuring device. Will be able to. If the workpiece fixing jig 50 is removed from the mounting table 12, the roundness of a workpiece having a shape other than a spherical shape can be measured as usual as a normal roundness measuring device. The means for removably fixing the spherical workpiece fixing jig 50 to the mounting table 12 is not limited to the present embodiment.

  A cylindrical vacuum tank member 56 is fixed to the upper surface side of the base member 52 by screws 58 (see FIGS. 2 and 3). The vacuum tank member 56 has a hollow portion 62 (see FIGS. 2 and 3) inside the cylindrical side wall portion 60.

  The hollow portion 62 is for maintaining a vacuum state (negative pressure state) of the pipe connected to the hollow portion 62 for a long time, the lower end side is closed by the base member 52, and the upper end side from the side wall portion 60 in the radial direction. A portion excluding the central opening 64A is closed by the extended upper wall 64.

  In the side wall portion 60, two through holes 60 </ b> A and 60 </ b> B that connect the cavity portion 62 and the outside of the vacuum tank member 56 are formed at positions that are substantially opposite directions around the θ axis (a direction that forms approximately 180 degrees). .

  One through hole 60 </ b> A communicates with a pipe 66 that connects a vacuum ejector (not shown) that is a negative pressure generating means for generating a vacuum (negative pressure) and the vacuum tank member 56. A vacuum pressure gauge 68 is attached to the other through hole 60B.

  The pipe 66 includes a pipe 66A that is fixed to the vacuum tank member 56, and a pipe 66B that is separable from the pipe 66A and has one end connected to a vacuum ejector.

  The pipe 66A has a valve 70 that opens and closes an internal pipe line by the rotation of the lever 70A.

  Moreover, the vacuum pad 74 is attached to the edge part of the piping 66B as a component of the connection part 72 to which the piping 66A and the piping 66B are attached so that attachment or detachment is possible. The vacuum pad 74 is vacuum-adsorbed to the end of the pipe 66A by the operation of the vacuum ejector to connect the pipe 66A and the pipe 66B.

  A disk-shaped fixing member 76 is fixed to the upper surface of the upper wall portion 64 of the vacuum tank member 56 with screws 78. The fixing member 76 has a protruding portion 76A that protrudes in a cylindrical shape on the lower surface side, and the protruding portion 76A fits into the opening 64A of the upper wall portion 64 without a substantial gap.

  Further, the fixing member 76 is formed with a through hole 76 </ b> B penetrating from the lower surface of the protruding portion 76 </ b> A facing the cavity 62 to the upper surface of the fixing member 76.

  On the other hand, on the upper surface of the fixing member 76, a T-shaped joint 80 having a pipe branching into three and having three connection ends 80A, 80B, 80C is attached.

  The connection end 80 </ b> C is connected to the fixing member 76, and the through hole 76 </ b> B of the fixing member 76 communicates with the pipe line inside the joint 80. The pipe is branched into two pipes, a connection end 80A and a connection end 80B.

  One end of each of the two flexible tubes 82A, 82B is connected to each of the two connection ends 80A, 80B of the joint 80, and each of the two pipes branched by the joint 80 is the tube 82A, It communicates with each pipe line of 82B.

  The other end of each of the tubes 82A and 82B is connected to a weight member 84 to be described later via hard connection ends 83A and 83B.

  A cylindrical support member 86 extending along the θ axis is disposed on the upper surface side of the fixing member 76.

  A flange portion 88 that protrudes radially outward is formed at the lower end of the support member 86, and the flange portion 88 is fixed to the fixing member 76 by a screw 90.

  The support member 86 has a hollow portion 86A inside, and has cuts 92A, 92B, 94A, 94B extending in the vertical direction at the lower end portion and the upper end portion. The cuts 92A and 92B, and the cuts 94A and 94B are formed at positions that are substantially opposite to each other around the θ axis, that is, at positions that are opposite to each other across the θ axis.

  In the joint 80 described above, the connection end 80C is disposed in the hollow portion 86A inside the support member 86, and each of the connection end 80A and the connection end 80B is disposed in each of the cut 92A and the cut 92B. Then, one end of each of the tubes 82A and 82B disposed outside the support member 86 is connected to each of the connection ends 80A and 80B in the cuts 92A and 92B.

  A cylindrical weight member 84 acting as a weight is disposed in the hollow portion 86A of the support member 86 so as to be movable in the vertical direction.

  The weight member 84 includes a pipe line 85 having openings as pipe line ends 85A, 85B, and 85C at two locations on the opposite side surface (circumferential surface) across the central axis and the approximate center of the upper surface, A T-shaped pipe 85 is formed to communicate the pipe ends 85A, 85B, 85C with each other.

  Then, the connection ends 83A and 83B of the tubes 82A and 82B are connected to the pipe end 85A and the pipe end 85B through the cuts 94A and 94B.

  Accordingly, the weight member 84 is limited to a range in which at least the connection ends 83A and 83B can move with respect to the cuts 94A and 94B with respect to the vertical movement range. In particular, the range of movement of the weight member 84 to the lower side is limited to a position where the tubes 82A and 82B come into contact with the lower ends of the cuts 94A and 94B.

  A cylindrical suction pad 96 is erected on the upper surface of the weight member 84, and a pipe line penetrating from the lower end to the upper end of the suction pad 96 is connected to the pipe end 85 </ b> C of the weight member 84.

  The upper end of the suction pad 96 has a circular opening, and the workpiece W is sucked and held by a suction force acting on this opening as will be described later.

  A disk-shaped table member 98 is fixed to and supported by the upper end of the support member 86 with screws or the like. At the center of the table member 98, a work placement unit 100 on which the work W is placed is provided.

  As shown in FIG. 5 that is an enlarged view of the workpiece placement unit 100 in FIG. 3, the workpiece placement unit 100 has a table member 98 that extends from the upper surface to the lower surface along a central axis that is substantially coaxial with the θ axis. It has a columnar workpiece placement hole 101 that passes therethrough.

  The spherical workpiece W is placed in a state where a part of the lower side is immersed in the workpiece placement hole 101 and is sucked by the suction pad 96 inserted from the lower side of the workpiece placement hole 101.

  In addition, the work placement unit 100 is arranged at equal intervals along the circular periphery of the work placement hole 101 at the periphery of the work placement hole 101 on the upper surface side of the table member 98 (rotation of about 120 degrees around the θ axis). Three support point balls 102A, 102B, and 102C are installed at every angular interval (see FIGS. 4 and 5).

  The support point balls 102A, 102B, and 102C are formed in a spherical shape from a hard material such as ruby, and are attached to the tips of screw members 104A, 104B, and 104C (only the screw member 104A is shown in FIG. 5). Then, the screw members 104A, 104B, and 104C are screwed into screw holes formed in the table member 93, whereby the supporting point balls 102A, 102B, and 102C are fixed to the upper surface of the table member 98.

  The workpiece W is supported by three points by coming into contact with these supporting point balls 102A, 102B, and 102C.

  When the diameter of the workpiece W is 8 mm, for example, when the diameter of the support point balls 102A, 102B, and 102C is 1 mm, the center of the workpiece W is about 1.5 mm with respect to the center of the support point balls 102A, 102B, and 102C. Supported in a high position.

  Next, the operation of the spherical workpiece fixing jig 50 will be described.

  When measuring the roundness of the spherical workpiece W, the operator fixes the spherical workpiece fixing jig 50 to the mounting table 12 as described above. Then, the spherical workpiece W is placed at the position of the workpiece placement hole 101 in the table member 98 of the spherical workpiece fixing jig 50, and the workpiece W is placed on the support point balls 102A, 102B, 102C.

  Subsequently, the lever 70A of the valve 70 is operated to open the valve 70 (open the internal pipe line of the valve 70) and operate the vacuum ejector. Then, the vacuum pad 74 at the end of the pipe 66B connected to the vacuum ejector is vacuum-adsorbed to the end of the pipe 66A including the valve 70 to connect the pipe 66A and the pipe 66B (state of FIG. 4).

  Thereby, the vacuum tank member 56 and the vacuum ejector are connected by the pipe 66, and the air in the cavity 62 inside the vacuum tank member 56 is sucked by the vacuum ejector through the pipe 66, so that the cavity 62 is in a negative pressure state. Become.

  When the hollow portion 62 is in a negative pressure state, a suction force is generated at the opening at the upper end of the suction pad 96 via each of the fixing member 76, the tubes 82A and 82B, and the weight member 84.

  Subsequently, for example, the operator grips and moves the connection ends 83 </ b> A and 83 </ b> B, which are connection portions between the tubes 82 </ b> A and 82 </ b> B, and the weight member 84, and moves the suction pad 96 together with the weight member 84. Then, the suction pad 96 is vacuum-sucked to the lower part of the work W.

  Thereby, downward gravity corresponding to the weight of the weight member 84 is applied to the workpiece W. Then, the weight of the weight member 84 is added to the workpiece W, so that even when the workpiece W is light, the workpiece W is strongly pressed against the supporting point balls 102A, 102B, 102C, and is moved in the horizontal direction and the vertical direction. Variation is regulated.

  Next, it is confirmed by the vacuum pressure gauge 68 connected to the vacuum tank member 56 that the internal pressure of the cavity 62 has dropped to a predetermined appropriate pressure, and the lever 70A of the valve 70 is operated to operate the valve 70. Is closed (the internal conduit of the valve 70 is closed).

  Then, the vacuum ejector is stopped, the vacuum pad 74 of the pipe 66B is pulled away from the end of the pipe 66A, and the pipe 66B is removed from the pipe 66A as shown in FIG.

  Thereby, the spherical workpiece fixing jig 50 can be rotated around the θ axis without being obstructed by the pipe 66B and the vacuum ejector.

  Further, even if the vacuum portion is not sucked by the vacuum ejector due to the cavity 62 of the vacuum tank member 56 and a leak from the gap between the workpiece W and the suction pad 96 occurs, the negative pressure state is maintained. It is possible to maintain the suction state of the suction pad 96 on the work W while maintaining the length. Therefore, the weight member 84 is maintained in a connected state without being detached from the workpiece W during measurement.

  Next, the tip of the probe 24B of the detector 24 is brought into contact with the position of the bus bar of the workpiece W. At this time, for example, the axis of the detector body 24A is in the Z-axis direction (state shown in FIG. 1), the displacement direction of the probe 24B is in the X-axis direction (radial direction), and the biasing direction of the probe 24B with respect to the detector body 24A As shown in FIG. 8 to be described later on the workpiece W side, the tip of the probe 24B is brought into contact with the position of the bus bar of the workpiece W. In addition, the measuring element 24B is set in a state of being displaced in the direction opposite to the urging direction against the urging force by contact with the work W, and a predetermined measuring pressure (measuring force) is applied to the work W from the measuring element 24B. It is assumed that it has been added.

  Subsequently, a detection signal indicating the amount of displacement of the probe 24B is output from the detector 24 while rotating the mounting table 12 by the rotation driving unit 11 and rotating the workpiece W around the θ axis together with the spherical workpiece fixing jig 50. .

  As a result, the roundness and the like are calculated in the arithmetic processing unit that has acquired the detection signal from the detector 24.

  According to the spherical workpiece fixing jig 50 as described above, when the workpiece W rotates around the θ axis, the probe 24B applies a predetermined measuring force to the workpiece W along the bus bar of the workpiece W. The rotation around W is relatively rotated.

  As a result, the workpiece W receives a force in the horizontal direction by the measuring force from the probe 24B. When the workpiece W is light, the workpiece W moves in the horizontal direction or the upward direction by the measuring force only by its own weight, and high-precision measurement cannot be performed.

  On the other hand, in the above-described spherical workpiece fixing jig 50, the weight member 84 is connected to the workpiece W via the suction pad 96, so that the weight of the weight member 84 can be reduced. A downward force due to weight is added.

  Therefore, even when the workpiece W is light, the workpiece W is strongly pressed against the supporting point balls 102A, 102B, and 102C, and the movement of the workpiece W in the horizontal direction and the vertical direction with respect to the measuring force is restricted. Therefore, highly accurate measurement is possible.

  Here, conditions for preventing the workpiece W from moving by the measuring force will be described in detail.

  FIG. 7 is an image diagram showing the workpiece placement unit 100 in the spherical workpiece fixing jig 50 from above, and FIG. 8 is an image diagram showing the workpiece placement unit 100 from the side.

  As shown in these drawings, the workpiece W is constituted by three support point balls 102A, 102B, and 102C arranged at equal intervals (120-degree intervals) around the θ axis that is an axis in the vertical direction passing through the center of the workpiece W. Supported.

  Further, it is assumed that an angle formed between a straight line connecting the center of the workpiece W and the centers of the supporting point balls 102A, 102B, and 102C and the θ axis is α degrees.

  Further, the probe 24B of the detector 24 includes a plane including the θ-axis and the center of one support point ball (for example, the support point ball 102A), and a generatrix of the workpiece W (the contour of a horizontal section passing through the center of the workpiece W). Assume that the tip of the measuring element 24B is in contact with the position of the intersection with the line.

  A measuring force applied to the workpiece W by the measuring element 24B is Fm, a downward force due to gravity acting on the workpiece W due to the weight of the workpiece W and the weight member 84 is Fw, and the workpiece W is supported by each supporting point ball 102A, The component force applied to 102B and 102C is assumed to be Fa. The component force Fa applied to each of the support point balls 102A, 102B, 102C is equally distributed in a state where the measurement force Fm is not applied. Further, the horizontal component of the component force Fa is Fah, and the vertical component (vertical component) is Fav.

  Under such a premise, the condition for preventing the workpiece W from moving by the measuring force Fm is expressed by the following conditional expression (1).

Fah> Fm (1)
That is, if the horizontal component Fah of the component force Fa applied from the workpiece W to the support point ball 102A is larger than the measurement force Fm, there is no possibility that the workpiece W is at least separated from the support point ball 102A, and the conditional expression (1) can be satisfied. There is no possibility that the workpiece W will move.

Here, the vertical component Fav of the component force Fa received by each supporting point ball 102A, 102B, 102C is:
Fav = Fw / 3 (2)
It is.

  Since the vertical component Fav is Fa · cos α and the horizontal component Fah is Fa · sin α, the horizontal component Fah of the component force Fa is expressed by the following equation (3) in consideration of the above equation (2). Become.

Fah = Fa · sin α = (Fav / cos α) · sin α
= Fw · tanα / 3 (3)
Therefore, the above conditional expression (1) is expressed by the following conditional expression (4).

Fw · tanα / 3> Fm (4)
For example, when Fm = 0.1N (≈10 gf) and α = 30 °, the above conditional expression (1)
Fw> 3 · Fm / tan α = 3 · 0.1 / tan 60 °
= 0.17 N (≈ 17 gf)
Therefore, if the workpiece W and the weight member 84 are 17 g or more, the workpiece W can be prevented from moving by the measuring force Fm.

  On the other hand, FIG. 9 and FIG. 10 show a case where the measuring element 24B is in contact with the bus bar of the work W at a position opposite to the state shown in FIGS. FIG. 9 is an image diagram showing the workpiece placement unit from above, and FIG. 10 is an image diagram showing the workpiece placement unit from the side.

  In this state, of the supporting point balls 102A, 102B, and 102C, there are two supporting point balls that separate the workpiece W when the workpiece W moves in the direction of the measuring force Fm. For example, the support point balls 102B and 102C correspond to this in the example of FIG.

  Then, a force when a component in the opposite direction to the measurement force Fm among the horizontal component Fah of the component force Fa applied thereto is combined is defined as Fbh.

  At this time, if the force Fbh is larger than the measuring force Fm, there is no possibility that at least the workpiece W is separated from the two support point balls 102B and 102C, and there is no possibility that the workpiece W moves.

  Therefore, the condition for preventing the workpiece W from moving by the measuring force Fm is expressed by the following conditional expression (5).

Fbh> Fm (5)
Here, with respect to the horizontal component Fah of the component force Fa applied to each of the support point balls 102B and 102C, the component opposite to the measurement force Fm is Fah · sin30 ° = Fah / 2. Therefore, the force Fbh obtained by combining the components Fah / 2 for the supporting point balls 102B and 102C is equal to Fah, and the above conditional expression (5) is equal to the conditional expression (1).

  Therefore, even in this state, the workpiece W can be prevented from moving by the measuring force Fm by satisfying the conditional expression (4).

  As described above, in the above-described embodiment, the piping 66 connecting the suction pad 96 and the vacuum ejector inhibits the rotation of the work W, so that the vacuum ejector is separated from the suction pad 96 when the work W rotates. I made it.

  However, for example, a pipe that is connected to the suction pad and rotates together with the workpiece W and a pipe that is connected to the vacuum ejector and is fixed are connected using a rotary joint. it can. In this case, it is not necessary to disconnect the vacuum ejector as in the above embodiment when the workpiece W is rotated (during measurement), and the vacuum ejector can be operated even during measurement. Further, a cavity for holding a vacuum such as the cavity 62 of the vacuum tank member 56 can be eliminated.

  However, since such a rotary joint needs to be arranged in a non-rotating portion, for example, the rotation driving unit 11 under the mounting table 12, all of the spherical workpiece fixing jigs are connected to the roundness measuring device. It is difficult to make the components completely removable.

  Therefore, the existing roundness measuring device cannot be used as it is, and it is necessary to change some configurations in advance.

  On the other hand, the spherical workpiece fixing jig 50 shown in FIGS. 3 to 5 can completely attach / detach all the components of the spherical workpiece fixing jig to the roundness measuring apparatus. There is an advantage that the existing roundness measuring device can be used as it is.

  In the case of a detector rotation type roundness measuring device in which the detector 24 rotates around the workpiece W, it is necessary to disconnect the vacuum ejector as in the above embodiment when the detector rotates (during measurement). The vacuum ejector can be operated even during measurement. Further, a cavity for holding a vacuum such as the cavity 62 of the vacuum tank member 56 can be eliminated.

  In the above embodiment, a downward force on the workpiece W is applied by the weight member 84. However, the biasing member 120 such as a spring applies the workpiece W via the member 122 and the suction pad 96 as shown in FIG. You may make it add downward force. The member 122 corresponds to the weight member 84 of the above-described embodiment. However, the member 122 is not intended to add gravity due to its weight to the workpiece W, and may be light.

  In the above embodiment, the workpiece W is supported at the three points by the support point balls 102A to 102C on the table member 98, but the present invention is not limited to this. What is necessary is just to support the workpiece | work W by the control member which controls the downward movement of the workpiece | work W. FIG.

  Further, in the above-described embodiment, a downward force is applied to the workpiece W by the load member such as the weight member 84 or the biasing member 120 of FIG. 11, and the restriction member such as the support point balls 102A to 102C in the table member 98 However, the downward movement of the workpiece W is regulated to support the workpiece W, but the present invention is not limited to this.

  For example, it is in a direction perpendicular to the plane including the generatrix that moves the probe 24B while being in contact with the workpiece W, and is in contact with the hemisphere range on the first direction side in the first direction and the second direction that are opposite to each other. Any configuration including a regulating member that regulates the movement of the workpiece W in the first direction and a load unit that applies a force in the first direction to the workpiece W may be used. Can be direction.

  In the above embodiment, the load means such as the weight member 84 is connected to the work W via the suction pad 96, but the connection member can be attached to and detached from the work W by means other than suction, for example, magnetic force or adhesive. You may connect to.

  That is, a connecting member that is connected to the workpiece W in a range on the first direction side from the contact position of the regulating member, and a connecting means that removably connects the connecting member to the workpiece W. Further, any means other than the suction means and a load means for applying a force in the first direction to the workpiece W via the connecting member can be employed.

  DESCRIPTION OF SYMBOLS 1 ... Roundness measuring apparatus, 11 ... Rotation drive part, 12 ... Mount stage, 24 ... Detector, 24B ... Measuring element, 50 ... Spherical workpiece fixing jig, 56 ... Vacuum tank member, 62 ... Cavity part, 66 ... Piping, 70 ... Valve, 84 ... Weight member, 96 ... Suction pad, 98 ... Table member, 100 ... Work placement part, 101 ... Work placement hole, 102A-102C ... Supporting point ball

Claims (13)

A roundness measuring device that measures the roundness of a measurement object by moving the measuring element relative to the position of the bus bar relative to a spherical measurement object while moving the relative distance along the bus line,
The first direction side of the measurement object in contact with the hemispherical range on the first direction side in the first direction and the second direction opposite to each other in a direction perpendicular to the plane including the generatrix of the measurement object A restricting member that restricts movement to
A connecting member connected to the measurement object in a range on the first direction side than the contact position of the regulating member;
A coupling means for detachably coupling the coupling member to the measurement object;
Load means for applying a force in the first direction to the measurement object via the connecting member;
Roundness measuring device with The connecting member is a suction pad;
The connecting means includes
Negative pressure generating means for generating negative pressure;
Piping connecting the suction pad and the negative pressure generating means;
The roundness measuring apparatus according to claim 1, comprising: The piping is
A connecting portion for detachably connecting the negative pressure generating means;
A valve that is disposed between the suction pad and the connecting portion and opens and closes a pipe;
A tank that maintains a negative pressure disposed between the suction pad and the valve;
The roundness measuring apparatus according to claim 2, comprising:   The roundness measuring apparatus according to claim 1, wherein the load means is a weight member connected to the connecting member.   The roundness according to any one of claims 1 to 4, wherein the regulating member is a fulcrum member that passes through the center of the measurement object and contacts at three points around an axis parallel to the first direction. measuring device.   The roundness measuring apparatus according to claim 1, wherein the bus line is a contour curve in a horizontal section passing through a center of the measurement object, and the first direction is a vertically downward direction. A measuring object fixing jig that is detachably attached to a roundness measuring apparatus and fixes a spherical measuring object, and a measuring element of the roundness measuring apparatus is positioned on a bus bar with respect to the measuring object A measuring object fixing jig of a roundness measuring device for measuring the roundness of a measuring object by moving it relatively along a generatrix while being in contact with
The first direction side of the measurement object in contact with the hemispherical range on the first direction side in the first direction and the second direction opposite to each other in a direction perpendicular to the plane including the generatrix of the measurement object A restricting member that restricts movement to
A connecting member connected to the measurement object in a range on the first direction side than the contact position of the regulating member;
A coupling means for detachably coupling the coupling member to the measurement object;
Load means for applying a force in the first direction to the measurement object via the connecting member;
A measuring object fixing jig of a roundness measuring apparatus including The connecting member is a suction pad;
The connecting means includes
Negative pressure generating means for generating negative pressure;
Piping connecting the suction pad and the negative pressure generating means;
The measuring object fixing jig of the roundness measuring apparatus according to claim 7. The piping is
A connecting portion for detachably connecting the negative pressure generating means;
A valve that is disposed between the suction pad and the connecting portion and opens and closes a pipe;
A tank that maintains a negative pressure disposed between the suction pad and the valve;
The measuring object fixing jig of the roundness measuring apparatus according to claim 8, comprising:   The measuring object fixing jig of the roundness measuring device according to any one of claims 7 to 9, wherein the load means is a weight member connected to the connecting member.   The roundness according to any one of claims 7 to 10, wherein the restriction member is a fulcrum member that passes through the center of the measurement object and contacts at three points around an axis parallel to the first direction. Fixing jig for measuring object of measuring device.   The roundness measuring device according to any one of claims 7 to 11, wherein the generatrix is a contour curve in a horizontal section passing through the center of the measurement object, and the first direction is a vertically downward direction. Measuring object fixing jig. A mounting table included in the roundness measuring device, wherein the regulating member, the connecting member, and the load means are attached to and detached from the mounting table on which a cylindrical or columnar measuring object is mounted. The measuring object fixing jig of the roundness measuring apparatus according to any one of claims 7 to 12, which is detachably mounted.

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