JP5854249B1 - Shape measuring device - Google Patents

Abstract

Provided is a shape measuring device capable of easily and stably exchanging a plurality of measuring elements and avoiding an impact. In a shape measuring device for measuring the roughness and / or contour of a workpiece surface by sliding a stylus provided on the distal end side of an arm in the axial direction of the arm with respect to the workpiece, the arm comprises: An engagement mechanism 52 that allows the stylus side of the arm to be detachable from the base end side of the arm has two engagement surfaces that are perpendicular to the work surface and parallel to the axial direction of the arm. 62, 82, and a mechanism in which the magnet 90 and the magnetized member 68 at the corresponding positions in the engagement surface adsorb each other, and the stylus arm on the engagement surface has a proximal end side. The arm on the stylus side presses or pulls the arm on the base end side, and the arm on the side of the stylus slides on the surface of the section on the base, Remove from the arm. [Selection] Figure 3

Description

  The present invention relates to a shape measuring apparatus, and more particularly to a shape measuring apparatus capable of exchanging a plurality of measuring elements.

  By moving a detector having a probe along the surface of the workpiece (workpiece), converting the displacement of the tip of the probe into an electrical signal and reading it into an arithmetic processing unit (computer) such as a computer A shape measuring device for measuring a surface shape such as a surface roughness and a contour of a workpiece is known.

  In the shape measuring apparatus, the shape of the workpiece is measured by exchanging the measuring piece according to the shape of the workpiece from a plurality of measuring pieces.

  Patent Document 1 discloses a surface texture measuring instrument having a measurement arm including a first measurement arm supported to be swingable with a support shaft as a fulcrum and a second measurement arm including a stylus provided via an attachment / detachment mechanism. To do. The attachment / detachment mechanism includes a positioning mechanism, a magnetic body, and a magnet.

JP 2012-225742 A

  The positioning mechanism of the attaching / detaching mechanism of Patent Document 1 includes a seating portion configured by a pair of columnar positioning members and an engaging ball portion corresponding to the seating portion. In this positioning mechanism, the engaging ball portion is intended to be fitted at a correct position while being guided by a pair of columnar positioning members constituting the seating portion.

  However, in a configuration such as a pair of columnar positioning members and an engagement ball portion, the engagement ball portion is fitted by the position of the pair of columnar positioning members and the engagement ball portion before being fitted into the correct position. There is a problem in the stability of the alignment because the pulling force (component force) changes until it is inserted.

  In addition, the second measurement arm including the stylus may receive an unexpected external force, and the second measurement arm and the first measurement arm may collide and receive an impact.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a shape measuring apparatus capable of stably exchanging a plurality of measuring elements and avoiding an impact.

  The shape measuring apparatus according to one aspect of the present invention is a shape in which the stylus provided on the tip side of the arm is slid in the axial direction of the arm with respect to the workpiece to measure the roughness and / or contour of the workpiece surface. In the measuring apparatus, the arm has an engagement mechanism that allows the stylus side of the arm to be detachable from the proximal end side of the arm, and the engagement mechanism is perpendicular to the workpiece surface and is A mechanism having two engaging surfaces that are parallel and opposite to each other in the axial direction, and that attracts each other by a magnet and a magnetized member at corresponding positions in the engaging surface, The stylus arm has a riding section that rides on the proximal arm, and when the stylus arm presses or pulls the proximal arm, the stylus arm Slide on the surface of the riding section Disengaged from the arm of the proximal-side.

  Preferably, the opposing engagement surfaces are perpendicular to the workpiece.

  Preferably, the engaging surface opposite to the engaging surface on which the riding portion is formed has a surface facing the riding portion, and the surface slides on the surface of the riding portion.

  Preferably, a detection circuit for detecting contact and non-contact is configured by the operation pin provided with one of the engagement surfaces and the sensor provided with the other engagement surface.

  According to the shape measuring apparatus of the present invention, a plurality of measuring elements can be exchanged easily and stably, and an impact can be avoided.

It is an external view of a shape measuring apparatus. It is a schematic block diagram of a measuring element and a displacement detector. It is a disassembled perspective view which shows an engagement mechanism. It is a perspective view which shows the engagement state of an engagement mechanism. It is explanatory drawing for demonstrating retraction force. It is explanatory drawing explaining the engagement direction of an engagement mechanism. It is explanatory drawing for demonstrating the function of a sensor and an operating pin. It is explanatory drawing for demonstrating the position of a sensor and an operating pin. It is a schematic block diagram which shows the engagement mechanism for avoiding an impact. It is a schematic block diagram which shows another engagement mechanism for avoiding an impact. It is a schematic block diagram which shows another engagement mechanism for avoiding an impact. It is a schematic block diagram which shows the some engagement mechanism for avoiding an impact. It is a schematic block diagram which shows the difference between this embodiment and the conventional engagement mechanism.

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

  FIG. 1 is an external view of a shape measuring apparatus to which the present invention is applied. The shape measuring apparatus 10 includes a surface plate 12, a support column 14 provided on the surface plate 12, an X-axis drive unit 16 movable in the X-axis direction supported by the support column 14 so as to be movable in the Z-axis direction, A displacement detector 18 attached to the shaft drive unit 16, a probe 20 detachably attached to the displacement detector 18, an input device 22 for giving an instruction to a control device (not shown), a measurement result, etc. A display device 24 is displayed.

  FIG. 2 is a schematic diagram showing the structure of the probe 20 and the displacement detector 18. The tracing stylus 20 includes a tracing stylus arm 30 and styluses 32 provided on both sides for measuring the shape provided on the distal end side of the tracing stylus arm 30. In the embodiment, the probe 20 having the stylus 32 provided on both sides for measuring the shape at the tip of the probe arm 30 is shown. However, if the stylus 32 provided on one side for measuring the shape is provided at least. good.

  The displacement detector 18 includes a drive unit coupling unit 40, a movable unit 44 rotatably supported on a rotation shaft 42 provided in the drive unit coupling unit 40 along the Y-axis direction, and a movable unit with respect to the rotation shaft 42. 44, a displacement reading unit 46 provided on the front end side of 44, and a weight 48 whose position is adjusted on the opposite side of the displacement reading unit 46 with the rotation shaft 42 interposed therebetween.

  The displacement detector 18 includes a housing 50 that encloses the drive unit connecting unit 40, the movable unit 44, the displacement reading unit 46, and the weight 48. In the embodiment, a part of the drive unit connecting unit 40 and the movable unit 44 is disposed inside the housing 50. In the embodiment, the displacement reading unit 46 is provided on the distal end side of the movable unit 44 with respect to the rotation shaft 42, but may be provided on the weight 48 side.

  As the displacement reading unit 46, a linear scale, an arc scale, an LVDT (Linear variable differential transformer), or the like can be used.

  The probe arm 30 of the probe 20 and the movable portion 44 of the displacement detector 18 are detachably engaged by an engagement mechanism 52 described below. The tracing stylus arm 30 and the movable portion 44 constitute one arm via an engagement mechanism 52. The engagement mechanism 52 is provided outside the housing 50 of the displacement detector 18.

  By adjusting the position of the weight 48, the load (measurement force) generated on the stylus 32 can be changed. Depending on the workpiece to be measured, the displacement detector 18 may not be provided with the weight 48.

  When performing measurement, the stylus 32 provided at the tip of the probe 20 of the displacement detector 18 is brought into contact with the surface of a workpiece (not shown) placed on the surface plate 12 with a constant force. Let In this state, the X-axis drive unit 16 moves the probe 20 and the displacement detector 18 along the X-axis, that is, slides in the axial direction of the arm. When the arm is slid in the axial direction, the stylus 32 is displaced in the Z-axis direction according to the shape of the surface of the workpiece. An arm composed of the measuring element arm 30 and the movable portion 44 rotates around the rotation shaft 42. The displacement reading unit 46 detects the displacement of the movable unit 44. As a result, a signal corresponding to the displacement of the stylus 32 in the Z-axis direction is output from the displacement reading unit 46. Surface properties such as surface roughness and / or contour shape of the workpiece can be measured.

  In the surface roughness measurement, minute unevenness on the workpiece surface is detected, and a height change in a minute length of the workpiece surface, that is, a height change in a short cycle is detected. On the other hand, the contour shape measurement detects a change in height of the workpiece surface over a relatively long period.

  Next, the detachable engagement mechanism 52 of this embodiment will be described with reference to FIG. As shown in FIG. 3, the detachable engagement mechanism 52 includes a first engagement member 60 provided on the proximal end side of the tracing stylus arm 30 and a second engagement provided on the distal end side of the movable portion 44. The member 80 is comprised. That is, the engagement mechanism 52 makes the stylus side (measurement arm 30) of the arm detachable with respect to the base end side (movable part 44) of the arm. The first engagement member 60 and the second engagement member 80 have two engagement surfaces 62 and 82 that are perpendicular to the workpiece surface and parallel to the axial direction (X-axis direction) of the arm, and are opposed to each other. The magnetized member 68 and the magnet 90 at the corresponding positions in 62 and 82 are detachably attracted to each other. The term “perpendicular to the work surface” includes “perpendicular” (parallel to the Z axis) and “substantially perpendicular”. The two engaging surfaces 62 and 82 facing each other in parallel include being parallel and being substantially parallel.

  The first engagement member 60 is made of metal and has a substantially rectangular parallelepiped shape. However, the material does not need to be a rigid body as a whole, and may be a rigid body that does not deform even when at least the first groove 64 and the second groove 66 are repeatedly attached and detached. For example, when it is desired to reduce the weight of the engagement mechanism 52, a composite material in which a metal obtained by processing the first groove 64 and the second groove 66 at the same time and carbon is bonded may be used. Moreover, it is preferable that it is a nonmagnetic material so that adsorption | suction of the below-mentioned magnetized member 68 and the magnet 90 may not be inhibited. The first engaging member 60 includes a first groove 64 having a V-shaped cross section parallel to the axial direction of the measuring element arm 30 on an engaging surface 62 that contacts the second engaging member 80, and a measuring element arm. And a linear second groove 66 having a V-shaped cross section orthogonal to the 30 axial direction. In FIG. 3, the first groove 64 and the second groove 66 are crossed, but the first groove 64 and the second groove 66 may not be crossed. The first groove 64 and the second groove 66 may be collectively referred to as grooves 64 and 66.

  The first engaging member 60 has two circular magnetized members 68 at substantially target positions with the second groove 66 interposed therebetween. The material of the magnetizing member 68 is not limited as long as it is a magnetic body attracted by a magnet 90 described later.

  On the proximal end side of the engagement surface 62 of the first engagement member 60, the operation pin 70 is disposed through a through hole provided with the first engagement member 60.

  The second engagement member 80 is made of metal and has a substantially rectangular parallelepiped shape. However, like the first engagement member 60, the material does not need to be a rigid body as a whole, and may be a composite material, and is preferably a non-magnetic material. Compared with the first engagement member 60, the second engagement member 80 is configured to have a smaller thickness in the Y-axis direction.

  The second engagement member 80 is disposed on the engagement surface 82 that contacts the first engagement member 60 at a position corresponding to the first groove 64 and has a spherical first positioning pin 84 that engages with the first groove 64. A second positioning pin 86 and a spherical third positioning pin 88 that is disposed at a position corresponding to the second groove 66 and engages with the second groove 66 are provided. The first positioning pin 84, the second positioning pin 86, and the third positioning pin 88 may be collectively referred to as positioning pins 84, 86, 88.

  In the second engagement member 80, two circular magnets 90 are arranged on the engagement surface 82 at positions corresponding to the two magnetizing members 68. Further, a sensor 92 is provided at a position corresponding to the operation pin 70 on the proximal end side of the engagement surface 82 of the second engagement member 80.

  An inclined portion 94 that is inclined with respect to the X-axis direction on the proximal end side of the second engagement member 80 is provided on the engagement surface 82. The inclined portion 94 is inclined so as to approach the proximal end side of the second engaging member 80 as it approaches the engaging surface 62 of the first engaging member 60 when viewed from the Z-axis direction. The inclined part 94 is perpendicular to the work surface and inclined with respect to the engaging surface 82. The term “perpendicular to the work surface” includes “perpendicular” (parallel to the Z axis) and “substantially perpendicular”.

  An inclined surface 72 is provided at a position facing the inclined portion 94 of the second engaging member 80 of the first engaging member 60. An inclined surface 72 facing the inclined portion 94 is formed on the engaging surface 62 opposite to the engaging surface 82 where the inclined portion 94 is formed. The inclined surface 72 and the inclined portion 94 will be described later.

  As shown in FIG. 3, the engagement surface 62 of the first engagement member 60 and the engagement surface 82 of the second engagement member 80 are disposed at opposing positions. The first groove 64 and the second groove 66 of the first engagement member 60 are roughly aligned with the first positioning pin 84, the second positioning pin 86, and the third positioning pin 88 of the second engagement member 80. As shown by the arrow, the magnetized member 68 is attracted by the magnetic force of the magnet 90 along the Y-axis direction. As a result, the engaging surface 62 of the first engaging member 60 and the engaging surface of the second engaging member 80 are obtained. 82 is adsorbed.

  At that time, the first positioning pin 84 and the second positioning pin 86 are guided to the first groove 64, and the third positioning pin 88 is guided to the second groove 66. Thereby, the engagement surface 62 of the first engagement member 60 and the engagement surface 82 of the second engagement member 80 are aligned, and the first engagement member 60 and the second engagement member 80 are attracted by magnetic force. Is done.

  As shown in FIG. 4, the measuring element 20 and the movable portion 44 are detachably engaged by the engaging mechanism 52 including the first engaging member 60 and the second engaging member 80. In this embodiment, since the two magnets 90 and the two magnetized members 68 are provided, even if a force is applied from the direction indicated by the arrow A, the first engaging member 60 and the second engaging member are engaged. The adsorption state with the member 80 can be maintained. However, the magnetized member 68 and the magnet 90 may each have at least one.

  In the present embodiment, since the grooves 64 and 66 are made in a straight line by milling the first engaging member 60 or the like, the grooves 64 and 66 having excellent parallelism and orthogonality with respect to the tracing stylus arm 30. Can be obtained.

  When a plurality of measuring elements 20 are exchanged and used, it is necessary to always maintain the mounting accuracy (positioning accuracy, suction force, etc.) between the measuring element 20 and the movable portion 44 constant. In the present embodiment, since the grooves 64 and 66 having a V-shaped cross section that is simple in structure and easy to ensure processing accuracy are formed, the mounting accuracy can be maintained constant.

  Even when the first groove 64 is attached, the first groove 64 is formed in a straight line parallel to the relative feed direction, so that the first positioning pin 84 and the second positioning pin 86 are connected to the first groove 64. Just slide it to 64. Also when sliding, if it slides parallel to the X-axis direction and the third positioning pin 88 fits in the second groove 66, it can act on the magnetized member 68 and can be seated accurately.

  In addition, it is important that the first groove 64 is cut in parallel to the arm axis. This greatly affects the measurement accuracy especially in relation to the zero point position of the displacement detector on the base end side of the arm with respect to the Z-axis direction, that is, the direction in which the arm moves up and down. For example, when there are holes to be fitted separately and the mounting accuracy in the Z direction is ensured, the positional accuracy of each hole and the size of the hole must be formed accurately. If there is a slight shift in the Z-axis direction, that is, if the arm base end side and the arm measuring element side are not installed in parallel, the zero point of the displacement detector will shift, and the linearity may shift. In addition, there is an error in contact with the workpiece where the stylus contact position is not a desired position. Therefore, it is important that the mechanism is a mechanism for accurately attaching the arms to each other in parallel.

  It is also important that the first groove 64 is perpendicular to the measurement direction, in other words, the direction in which the measurement force acts. When a parallel force is applied to the groove, it does not move along the groove with a small force. However, even if a large force is applied to the groove in the vertical direction, it is not easily displaced and very stable. There is a feature to do. This is because the position where the positioning pin and the groove are in contact with each other is substantially in contact with and supported by only two points on the groove cross-section, that is, two points positioned mutually in the Z-axis direction.

  As described above, since the first groove 64 is formed in a straight line, the variation in component accuracy in the parallelism of the groove of the probe arm 30 itself to be replaced is small. In addition, since the seating is performed while sliding in parallel grooves, the reproducibility in the mounting is very high. As a result, it is possible to attach the various arms accurately and accurately. In particular, it is desirable that the first groove 64 is provided on the arm probe side if possible, because many of the arm probe sides are exchanged with respect to the base end portion of the arm.

  In FIG. 3, grooves 64 and 66 are provided in the first engagement member 60 provided on the proximal end side of the probe 20, and positioning pins 84, 86, and 88 are provided in the second engagement member 80 of the movable portion 44. An example was given. Without being limited thereto, positioning pins 84, 86, 88 can be provided on the first engagement member 60, and grooves 64, 66 can be provided on the second engagement member 80.

  That is, the first groove 64 and the second groove 66 are formed on either the engagement surface 62 of the first engagement member 60 or the engagement surface 82 of the second engagement member 80, and Positioning pins 84, 86, 88 can be provided on either the engagement surface 62 or the engagement surface 82 of the second engagement member 80.

  In addition, it is preferable to provide the grooves 64 and 66 in the first engagement member 60 provided on the proximal end side of the measuring element 20. When exchanging a plurality of measuring elements 20 according to the workpiece, it is preferable that the variation in positional accuracy between the measuring elements 20 is small. Therefore, it is preferable to provide the first engagement member 60 with grooves 64 and 66 that are simple in structure and easy to ensure processing accuracy.

  The second groove 66 may be not only a groove but a hole as long as it can be aligned with the third positioning pin 88. That is, the second groove 66 includes a groove and a hole.

  Next, regarding the pulling force (component force), the difference between the engagement mechanism of the present embodiment and the conventional engagement mechanism will be described with reference to FIG.

  Part (A) of FIG. 5 shows the engagement mechanism of this embodiment. As shown in the right figure, when the first engagement member and the second engagement member are attracted to the magnetic force, the positioning pins 84, 86, 88 and the grooves 64, 66 come into contact with each other. A suction force F acts on the positioning pins 84, 86, 88. The attracting force F is composed of a component force F1 perpendicular to the inclination in the grooves 64 and 66 and a pulling force (component force) F2 that moves to the seating position in a direction parallel to the inclination.

  When the first engagement member and the second engagement member are attracted by the magnetic force and the distance between the two approaches, the positioning pins 84, 86, 88 move to the bottoms of the grooves 64, 66, that is, the seating position due to the pull-in force F2. . As shown in part (A) of FIG. 5, the pull-in force F <b> 2 hardly changes during the period from when the positioning pins 84, 86, 88 are brought into contact with the grooves 64, 66 to when they are moved to the seating position. That is, the positioning pins 84, 86, 88 can be stably moved to the seating positions of the grooves 64, 66.

  Part (B) of FIG. 5 shows a conventional engagement mechanism. The conventional engagement mechanism is composed of a pair of cylindrical positioning members 200 and 200 and a spherical pin 210. As shown in the right figure, when the first engagement member and the second engagement member are attracted by the magnetic force, the one positioning member 200 and the pin 210 come into contact with each other. An adsorption force F acts on the pin 210. The attracting force F includes a component force F1 perpendicular to the tangential direction between the positioning member 200 and the pin 210 and a pulling force (component force) F2 parallel to the tangential direction. Since the pull-in force (component force) F2 is parallel to the tangential direction, the magnitude varies depending on the position where the positioning member 200 and the pin 210 are in contact with each other.

  When the first engagement member and the second engagement member are attracted by the magnetic force and the distance between the two approaches, the position where the pin 210 contacts the pair of columnar positioning members 200, 200 by the pull-in force F2, that is, the seating position Move up. As shown in part (B) of FIG. 5, the pull-in force F <b> 2 changes greatly after the pin 210 contacts the positioning member 200 and moves to the seating position. In particular, at the time of contact between the positioning member 200 and the pin 210, the pull-in force F2 is not large. When the pull-in force F2 is small, it takes time for the pin 210 to move to the seating position, and in some cases, the pin 210 may not be seated correctly due to a shortage of the pull-in force F2.

  In order to move the pin 210 to the seating position, the pulling force F2 can be increased by increasing the magnetic force and increasing the attracting force F. However, by increasing the suction force F, the engagement force between the first engagement member and the second engagement member becomes stronger. If it becomes so, when separating a 1st engagement member and a 2nd engagement member, big force will be needed and the ease of attachment or detachment may be inhibited.

  In the present embodiment, an example in which the angle θ of the grooves 64 and 66 having a V-shaped cross section is 90 ° is shown, but the contact force between the stylus 32 and the workpiece, the magnitude of the suction force F, the first groove 64 and the first groove The angle θ is determined in the range of 80 ° to 120 ° in consideration of the magnitude of the pull-in force F2 due to the difference in friction coefficient depending on the material of the two grooves 66.

  In this embodiment, the case where the grooves 64 and 66 have a V-shaped cross section has been described. However, the present invention is not limited to this, and the grooves 64 and 66 may have a U-shaped cross section, for example. Moreover, although the case where the positioning pins 84, 86, and 88 are spherical has been described, the positioning pins 84, 86, and 88 are not limited to spherical but may be hemispherical or the like. Also, the positioning pin shape may be formed slightly longer along the groove. Along with the linearity of the groove, extending the pins slightly in the longitudinal direction also has an effect of fitting the straight lines together, and the mounting parallelism of the arms may be improved. Furthermore, instead of a pin, a long mountain that can be fitted in a groove may be used. That is, two positioning pins may be used as one Nagayama pin. This is the same as one Nagayama in which two or more positioning pins are continuous. One Nagayama pin meets the requirements of two positioning pins. However, regardless of whether it is a pin or a long mountain, it is important that one of them always forms a straight groove along the arm axis direction.

  As long as the positioning pins 84, 86, 88 are shaped to be guided in the grooves 64, 66, the shapes of the positioning pins 84, 86, 88 and the grooves 64, 66 are not limited.

  In addition, it is desirable to set the material hardness of the member on the base end side higher between the engagement surface of the arm on the probe side and the engagement surface of the arm on the base end side.

  This is because the measuring element side is replaced whenever the measuring element is worn by measurement, but the proximal end side is hardly replaced. Therefore, it is desirable to use a slightly softer material for the engagement surface on the probe side than on the base end side in consideration of long-term use. For example, it is conceivable that the probe side is made of an aluminum alloy, a copper alloy, or the like, and the base end side is made of ceramic, stainless steel, titanium, cemented carbide, or the like. Both may be the same material such as stainless steel.

  Next, the engaging direction of the first engaging member 60 and the second engaging member 80 will be described with reference to FIG. In the aspect shown in FIG. 3, the case has been described in which the first engagement member 60 and the second engagement member 80 are engaged in close proximity along the Y-axis direction. As shown in FIG. 6, in the present embodiment, the first engagement member 60 and the second engagement member 80 can be brought closer to each other along the X-axis direction and engaged. In the present embodiment, the first groove 64 is formed linearly over the entire area in the X-axis direction of the engagement surface 62 of the first engagement member 60. The first engaging member 60 and the second engaging member 80 can be positioned and adsorbed while sliding the first positioning pin 84 and the second positioning pin 86 along the first groove 64.

  Next, functions of the sensor and the operating pin will be described with reference to FIG. FIG. 7A is a top view of the state in which the first engagement member 60 and the second engagement member 80 are engaged as seen from the Z-axis direction. In a state where the first engagement member 60 and the second engagement member 80 are engaged, the operating pin 70 of the first engagement member 60 and the sensor 92 of the second engagement member 80 are in contact with each other. The operating pin 70 and the sensor 92 constitute a detection circuit (not shown) that detects contact or non-contact. The detection circuit can detect contact and non-contact of the operating pin 70 and the sensor 92.

  In the state of FIG. 7A, the detection circuit detects that the operating pin 70 and the sensor 92 are in contact, and the shape measuring device notifies the operator that it is in contact.

  As shown in part (B) of FIG. 7, for example, when an unexpected force is applied to the tracing stylus arm 30, the operating pin 70 and the sensor 92 are in a non-contact state. The detection circuit detects that the operating pin 70 and the sensor 92 are in a non-contact state, and the shape measuring device informs the operator that it is in a non-contact state. Further, non-contact information from the detection circuit is transmitted to a control device (not shown), and the control device stops driving the X-axis drive unit 16 and stops measurement. Moreover, when the support | pillar 14 is driven, the drive of the support | pillar 14 is stopped. This is to prevent failure of the shape measuring apparatus.

  The operation pin 70 is fitted in the through hole of the first engagement member 60. The length of the operating pin 70 protruding from the engagement surface 62 can be adjusted by moving the operating pin 70 in the through hole. By adjusting the length of the operating pin 70, the sensitivity of the sensor 92 can be adjusted.

  Next, a preferred position of the sensor 92 will be described with reference to FIG. FIG. 8 is a perspective view of the engagement surface 82 of the second engagement member 80 as viewed from the Y-axis direction. The sensor 92 can be provided anywhere on the engagement surface 82 of the second engagement member 80. In the present embodiment, it is preferable that the sensor 92 is provided outside the virtual triangle TR connecting the positioning pins 84, 86, 88 and on the base end side of the second engagement member 80.

  When an unexpected force is applied to the tracing stylus arm 30 from the Y-axis direction, as shown in FIG. 7B, the first engagement member 60 has the second engagement member 80 with the tip side as a rotation fulcrum. Often leave. Therefore, it is preferable to dispose the sensor 92 on the proximal end side of the second engagement member 80 and away from the distal end side, and dispose the operation pin 70 on the proximal end side of the first engagement member 60. When a force is applied to the first engagement member 60, the longer the distance from the rotation fulcrum to the operation pin 70, the longer the movement distance of the operation pin 70. Therefore, the non-contact state can be detected with higher sensitivity.

  However, the positions of the operation pin 70 and the sensor 92 are not limited to the embodiment, and the positions of the sensor 92 and the operation pin 70 can be determined according to the sensitivity.

  Next, with reference to FIG. 9, the preferable form which avoids an impact from a X-axis direction is demonstrated. 9A is a top view of the state in which the first engagement member 60 and the second engagement member 80 are engaged as seen from the Z-axis direction. Similarly to the portion (A) of FIG. 7, the operating pin 70 of the first engagement member 60 and the second engagement member 80 are in a state where the first engagement member 60 and the second engagement member 80 are engaged. The sensor 92 is in contact.

  9B is a bottom view of the state in which the first engagement member 60 and the second engagement member 80 are engaged as seen from the Z-axis direction. In this state, the inclined surface 72 of the first engaging member 60 and the inclined surface of the inclined portion 94 of the second engaging member 80 are arranged at positions facing each other.

  As shown in part (C) of FIG. 9, for example, when the probe 20 receives a strong force (impact) from the X-axis direction while measuring the shape of the workpiece, the probe 20 and the first member The joint member 60 moves in the X-axis direction. When the moving distance of the first engagement member 60 is increased, the operating pin 70 and the sensor 92 of the second engagement member 80 are not in contact with each other.

  When the detection circuit detects non-contact, the control device stops driving the X-axis drive unit 16. However, the measuring element 20 and the first engaging member 60 that have received the impact move to the movable portion 44 side by inertial force. Next, the inclined surface 72 of the first engaging member 60 and the inclined portion 94 of the second engaging member 80 come into contact with each other, and the first engaging member 60 slides along the inclined portion 94 of the second engaging member 80. It is moved in the direction of arrow B while moving (sliding).

  That is, when the arm on the side of the stylus 32 (measurement arm 30) is pressed against the arm on the base end side (movable portion 44), the arm on the side of the stylus slides on the surface of the inclined portion 94 and moves to the base end side. Remove from the arm. Thereby, it can avoid that the 1st engagement member 60 and the movable part 44 contact, and it can prevent that an impact is added to the displacement detector 18 containing the movable part 44. FIG. In particular, it is possible to prevent an impact from being applied to the rotating shaft 42. This is because the reproducibility of the measurement accuracy of the displacement detector 18 may be reduced if an axial shift or the like occurs in the rotating shaft 42 due to an impact.

  Further, the operating pin 70 is located near the inclined surface 72 rather than the magnetized member 68 and the positioning pins 84, 86, 88. As a result, the actuating pin 70 is immediately removed according to the above principle. Even if an abrupt impact is applied in the X-axis direction, the displacement detector 18 can be protected by the release of the operating pin 70 immediately.

  In the present embodiment, the case where the engaging surfaces 62 and 82 include the inclined surface 72 and the inclined portion 94 has been described, but at least the inclined portion 94 is provided so that the arm on the stylus side is on the surface of the inclined portion 94. Can be removed from the proximal arm. When the inclined surface 72 is provided, the arm on the stylus side can be slid more easily on the surface of the inclined portion 94.

  Next, another preferred embodiment for avoiding an impact from the X-axis direction will be described with reference to FIG. The same configurations as the configuration of the engagement mechanism shown in FIG. FIG. 10 is a bottom view of the first engagement member 60 and the second engagement member 80 in a state where an impact is applied in the X-axis direction, as viewed from the Z-axis direction. In this embodiment, a notch portion 45 having an inclined surface parallel to the inclined portion 94 is formed on the distal end side of the movable portion 44 (base end side arm). Even when an impact is applied in the X-axis direction, contact between the first engagement member 60 and the movable portion 44 can be more reliably avoided. Here, the term “parallel” includes the case of being substantially parallel.

  FIG. 11 is a schematic configuration diagram showing another type of engagement mechanism. The same configuration as the configuration of the engagement mechanism shown in FIG. 9 or FIG.

  (A) part of FIG. 11 is the top view which looked at the state which the 1st engaging member 60 and the 2nd engaging member 80 are engaging from the Z-axis direction. In the present embodiment, positioning pins 84, 86, 88 are formed on the engaging surface 62 of the first engaging member 60. A first groove (not shown) and a second groove 66 are formed in the engagement surface 82 of the second engagement member 80.

  Further, the second inclined surface 100 is formed on the engaging surface 62 of the first engaging member 60 on the stylus side opposite to the inclined surface 72. Further, the second inclined portion 102 is formed on the engaging surface 82 of the second engaging member 80 on the stylus side opposite to the inclined portion 94. The 2nd inclined surface 100 and the 2nd inclined part 102 are each arrange | positioned in the position which opposes.

  As shown in part (B) of FIG. 11, when the probe 20 receives a strong force (impact) from the X-axis direction while measuring the shape of the workpiece, the probe 20 and the first engagement member 60 moves in the X-axis direction. Next, the inclined surface 72 of the first engaging member 60 and the inclined portion 94 of the second engaging member 80 come into contact with each other, and the first engaging member 60 slides along the inclined portion 94 of the second engaging member 80. It is moved in the direction of arrow C while moving (sliding).

  That is, when the arm on the side of the stylus 32 (measurement arm 30) is pressed against the arm on the base end side (movable portion 44), the arm on the side of the stylus slides on the surface of the inclined portion 94 and moves to the base end side. Remove from the arm. Thereby, it can avoid that the 1st engagement member 60 and the movable part 44 contact, and it can prevent that an impact is added to the displacement detector 18 containing the movable part 44. FIG.

  Further, when the measuring element 20 receives a strong force (impact) from the opposite direction to the X-axis direction while measuring the shape of the workpiece, the measuring element 20 and the first engagement member 60 are in the X-axis direction. Move in the opposite direction. The second inclined surface 100 of the first engaging member 60 and the second inclined portion 102 of the second engaging member 80 are in contact with each other, and the first engaging member 60 contacts the second inclined portion 102 of the second engaging member 80. It is moved while sliding (sliding) along (not shown).

  Next, refer to FIG. 12 for a plurality of modes for avoiding the impact when the arm (measurement arm 30) on the stylus 32 side presses or pulls the arm (movable part 44) on the base end side. To explain.

  A portion (A) of FIG. 12 shows one aspect of this embodiment. In the present embodiment, the second engagement member 80 is provided with an inclined portion 94 as a riding-up portion on which the stylus arm (measurement arm 30) rides on the proximal end arm (movable portion 44). .

  Therefore, when the stylus arm presses or pulls the proximal arm, the stylus arm slides on the surface of the inclined portion 94 (climbing portion) and disengages from the proximal arm. become.

  The (B) part of FIG. 12 has shown another aspect of this embodiment. In the present embodiment, the protrusion 110 is provided on the second engagement member 80 as a riding-up portion on which the stylus arm rides on the proximal end arm.

  Therefore, when the stylus arm presses or pulls the proximal arm, the stylus arm slides on the surface of the projection 110 (climbing portion) and disengages from the proximal arm. become.

  (C) part of FIG. 12 has shown another aspect of this embodiment. In the present embodiment, the protrusion 110 is provided on the second engagement member 80 as a riding-up portion on which the stylus arm rides on the proximal end arm. Further, the protrusion 112 is provided on the first engagement member 60 at a position facing the protrusion 110.

  Therefore, when the stylus arm presses or pulls the proximal arm, the projection 112 of the stylus arm slides on the surface of the projection 110 (climbing portion) and rides on the proximal side. It will come off the arm.

  (D) part of FIG. 12 has shown another aspect of this embodiment. In the present embodiment, the protrusion 110 is provided on the second engagement member 80 as a riding-up portion on which the stylus arm rides on the proximal end arm. Further, the inclined surface 72 is provided on the first engaging member 60 at a position facing the protruding portion 110.

  Therefore, when the stylus arm presses or pulls the proximal arm, the inclined surface 72 of the stylus arm slides on the surface of the protrusion 110 (climbing portion) and rides on the proximal side arm. It will come off the arm.

  If the engagement surfaces 62 and 82 are perpendicular to the workpiece, they will be released when a load exceeding a certain load is applied in the axial direction, regardless of the measurement pressure or sudden change in workpiece shape. Can be set. On the other hand, if the engagement surfaces 62 and 82 are in a direction parallel to the workpiece, the engagement surfaces 62 and 82 may be disengaged by the measurement pressure and may not be stable. The engaging surfaces 62 and 82 are preferably perpendicular to the workpiece.

  Finally, regarding the structure, the difference between the engagement mechanism of the present embodiment and the conventional engagement mechanism will be described with reference to FIG. Part (A) of FIG. 13 shows the engagement mechanism of the present embodiment. In the present embodiment, a V-shaped first groove 64 is formed in the engagement surface 62. Since the first groove 64 is formed by processing, the first groove 64 can be provided near the end surface of the first engagement member 60.

  Part (B) of FIG. 13 shows a conventional engagement mechanism. Since the conventional engagement mechanism has a pair of columnar positioning members 200 and 200, a holder (wall) 220 for holding the positioning members 200 and 200 is required. Therefore, as shown in FIG. 13, the engaging mechanism of this embodiment can make an engaging member small compared with the conventional engaging mechanism.

  In addition, when the engaging members have the same size, the first groove 64 can be formed on the end surface side, so that the distance between the first positioning pin 84 and the second positioning pin 86 and the third positioning pin 88 can be increased. That is, since the virtual triangle (see FIG. 8) connecting the positioning pins 84, 86, 88 can be enlarged, the first engagement member 60 and the second engagement member 80 can be stably engaged.

  DESCRIPTION OF SYMBOLS 10 ... Shape measuring apparatus, 12 ... Surface plate, 14 ... Support | pillar, 16 ... X-axis drive part, 18 ... Displacement detector, 20 ... Measuring element, 22 ... Input device, 24 ... Display apparatus, 30 ... Measuring element arm, 32 ... Stylus, 40 ... Drive part connecting part, 42 ... Rotating shaft, 44 ... Movable part, 45 ... Notch part, 46 ... Displacement reading part, 50 ... Housing, 52 ... Engaging mechanism, 60 ... First engaging member 62 ... engaging surface, 64 ... first groove, 66 ... second groove, 68 ... magnetized member, 70 ... operating pin, 72 ... inclined surface, 80 ... second engaging member, 82 ... engaging surface, 84 ... 1st positioning pin, 86 ... 2nd positioning pin, 88 ... 3rd positioning pin, 90 ... Magnet, 92 ... Sensor, 94 ... Inclined part, TR virtual triangle, 100 ... 2nd inclined surface, 102 ... 2nd inclined part , 110, 112 ... projections

Claims (5)

In the shape measuring device for measuring the roughness and / or contour of the workpiece surface by sliding the stylus provided on the tip side of the arm in the axial direction of the arm with respect to the workpiece,
The arm has an engagement mechanism that allows the stylus side of the arm to be detachable from the base end side of the arm, and the engagement mechanism is perpendicular to the workpiece surface and parallel to the axial direction of the arm. A mechanism having two engaging surfaces opposed to each other and attracting each other by a magnet and a magnetized member at corresponding positions in the engaging surface,
The stylus side arm slides on the base end side arm on the base end side with respect to the magnet and the magnetized member at the corresponding positions in the engaging surface. And a riding part that slopes or protrudes from one engaging surface to the opposing engaging surface side ,
A shape measuring device in which, when the stylus arm presses the proximal end arm, the stylus arm slides on the surface of the riding-up portion and disengages from the proximal end arm.   The shape measuring apparatus according to claim 1, wherein the opposing engagement surfaces are perpendicular to the workpiece.   The engagement surface on the opposite side of the engagement surface on which the riding portion is formed has a surface facing the riding portion, and the surface slides on the surface of the riding portion. The shape measuring apparatus described.   The detection circuit which detects a contact and non-contact is comprised by the operation pin provided with one said engagement surface and the sensor provided with the other said engagement surface. The shape measuring apparatus described.   The operation pin provided on the engagement surface and the sensor provided on the other engagement surface are located on the proximal side of the magnetized member and the magnet, and the sensor is non-contact when riding on the ride-up portion. The shape measuring apparatus according to claim 4, wherein the shape measuring apparatus stops driving the arm.

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