JP2017167168A - Three-dimensional measuring machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a three-dimensional measuring machine that has high visibility and can perform accurate measurement.SOLUTION: A Y-axis movable frame 22 for moving a probe 120 in a Y-axis direction is formed in an L shape, and its one end is movably supported by one Y-axis direct-acting guide 44 in the Y-axis direction. The other end is floated and supported on a surface plate 14 by an air bearing 70. Thus, the Y-axis movable frame 22 is supported in an oscillatable state about the Y-axis, and deformation such as torsion or deflection of the Y-axis movable frame 22 is prevented.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a three-dimensional measuring machine, and in particular, measures the shape, dimensions, etc. of a workpiece (measurement object) using probes provided so as to be movable in directions of X axis, Y axis, and Z axis orthogonal to each other. It relates to a three-dimensional measuring machine.

  The coordinate measuring machine is a contact-type measuring machine using a probe, and detects the coordinates (X, Y, Z) of the tip when the tip of the probe touches the workpiece (measurement object), and the coordinate value Measure the shape, dimensions, etc. of the workpiece from the set. For this reason, the probe is provided to be movable in each direction of three axes (X axis, Y axis, Z axis) orthogonal to each other.

  The mechanism for moving the probe is generally provided on a Y-axis moving body that moves along the Y-axis, an X-axis moving body that is provided on the Y-axis moving body and moves along the X-axis, and an X-axis moving body. The probe is attached to the Z-axis moving body. Since the accuracy of the mechanism for moving the probe is directly reflected in the measurement accuracy of the workpiece, it is important for the CMM to determine how accurately this can be configured. In particular, since the Y-axis moving body is mounted with the X-axis moving body and the Z-axis moving body on the Y-axis moving body, it is required to move with high accuracy without deformation. For this reason, in the coordinate measuring machine, various types of mechanisms for moving the probe along the Y axis have been proposed (for example, Patent Documents 1 and 2).

  FIG. 12A is a front view showing a schematic configuration of a three-dimensional measuring machine called a bridge type.

  The bridge-type coordinate measuring machine 1000 has a portal shape in which a Y-axis moving body 1002 includes a pair of legs 1002A and 1002B. The Y-axis moving body 1002 is supported slidably in the Y-axis direction with both leg portions 1002A and 1002B supported by air bearings. That is, one leg 1002A is slidably supported by one guide rail 1006 disposed on the base 1004 through the air pad 1008A, and the other leg 1002B is on the horizontal surface of the base 1004 through the air pad 1008B. It is slidably supported (for example, Patent Documents 3 and 4).

  As a bridge-type coordinate measuring machine, in addition to this, both a leg part is slidably supported by a mechanical linear motion guide bearing (linear motion guide) (for example, Patent Document 5), or one leg. There is known a system (for example, Patent Document 6) in which a part is slidably supported by a pair of mechanical linear motion guide bearings and the other leg part is slidably supported by an air bearing.

  FIG. 12B is a front view showing a schematic configuration of a three-dimensional measuring machine called a gantry type.

  In the gantry-type coordinate measuring machine 1100, the Y-axis moving body 1102 has a bar shape. The Y-axis moving body 1102 is arranged so as to bridge over a pair of columns 1106A and 1106B disposed on the base 1104, and is slidable on each column 1106A and 1106B via linear motion guides 1108A and 1108B. Supported (for example, Patent Document 7).

  FIG. 12C is a front view showing a schematic configuration of a three-dimensional measuring machine called a cantilever type.

  In the cantilever type coordinate measuring machine 1200, the Y-axis moving body 1202 has a bar shape. The Y-axis moving body 1202 is cantilevered by one column 1206 disposed on the base 1204, and is slidably supported on the column 1206 via a pair of linear motion guides 1208A and 1208B (for example, patents). Literature 8 etc.).

JP-A-5-248840 Special Table 2000-510241 No. 7-3283 JP-A-5-99651 No. 7-25605 JP 2006-287098 A JP 2010-122118 A JP 2010-181157 A

  A three-dimensional measuring machine of the bridge type in which both legs are levitated and supported by air bearings has the advantage that the Y-axis moving body can be guided with a small sliding resistance without causing deformation of the Y-axis moving body. .

  However, a three-dimensional measuring machine of the bridge type in which both legs are levitated and supported by air bearings has a problem that dynamic displacement in the pitching direction and yawing direction during acceleration / deceleration is large. The dynamic displacement in the pitching direction and yawing direction at the time of acceleration / deceleration appears as vibration and converges with time. However, if measurement is performed before convergence, there is a problem that a measurement error occurs. In particular, the bridge-type coordinate measuring machine has a configuration in which the center of gravity of the moving body is located above the support point on the driving side, and the distance therebetween is also separated, so that it is easy to fall down. As a result, the moment of inertia in the pitching direction is increased in proportion to the ease of falling during acceleration / deceleration, causing vibrations in the pitching direction and causing a drawback that pitching errors are likely to occur.

  In addition, a three-dimensional measuring machine of a bridge type in which both legs are levitated and supported by air bearings has no sliding resistance on both legs. In this case, when the Y-axis moving body is propelled at an intermediate position between both legs, the Y-axis moving body moves in a balanced manner, but when only one leg is driven, the driven leg moves with a delay. As a result, the left and right propulsion balance cannot be achieved. For this reason, there exists a fault that the dynamic error of a yawing direction becomes large.

  Further, when both the leg portions are levitated and supported by the air bearing, since there is no sliding resistance at all, it takes a long time to settle until the minute vibration after driving settles down.

  Furthermore, in the bridge type, the center of gravity position is relatively higher than the fulcrum position, so that the pitching error due to the inertial force when starting to move increases, and it takes a very long time for the forward / backward vibration due to the pitching to settle. There is also a drawback.

  In addition, the compressed air consumption is large and the running cost is high.

  On the other hand, a three-dimensional measuring machine of the bridge type in which both legs are supported by linear motion guides has a drawback that the sliding resistance generated in both legs is increased. And, if only one leg is driven with both sliding resistance being large, the driven leg is moved with a delay, so that the right and left propulsion cannot be balanced and the dynamic error in the yawing direction increases. There is a drawback. As a result, there is a drawback in that the hysteresis of movement increases on the left and right sides of the linear guide, yawing increases, and measurement errors are likely to occur.

  Further, since the drive unit is supported by the two linear motion guides, there is a disadvantage that the drive unit easily generates heat (the heat generation of the drive unit generates thermal stress in the apparatus main body and causes deformation of the guide unit).

  Furthermore, if the parallelism of the two linear motion guides is not maintained with high accuracy, or if the parallelism of the two linear motion guides gradually deteriorates over time, the linear motion guides will interfere with each other. As a result, the Y-axis moving body is deformed (twisted, bent, etc.) during movement, and the movement is not smooth. Generally, the error of the probe contact position due to the deflection of the Y-axis moving body can be corrected to some extent by a correction formula obtained from the measurement result of the reference workpiece, but it can be accurately corrected to the influence of the change in the deflection amount. There is a problem that is difficult.

  In addition, even in a coordinate measuring machine configured such that one leg is supported by a pair of linear motion guides and the other leg is supported by an air bearing, one leg is supported by two linear motion guides. There are drawbacks in that the sliding resistance is large and the drive unit is likely to generate heat.

  The support portions of the pair of linear motion guides have a structure that does not allow displacement in the rotational direction. In this case, when the parallelism between the pair of linear motion guides and the air bearing is not maintained with high accuracy, that is, strictly speaking, the level of the linear motion guide and the level position of the surface plate surface (work surface of the surface plate) Is changed in the Y-axis direction, the support part by the linear motion guide is flexible in response to the drag that the other leg receives from the air bearing in the process of the Y-axis moving body moving in the Y-axis direction. It cannot be rotated. As a result, there is a drawback that the Y-axis moving body is deformed in a form of warping in the X-axis direction. In general, the parallelism between the sliding surface of the linear motion guide and the sliding surface of the air bearing has a processing error.

  Similarly, the gantry type three-dimensional measuring machine is supported by two linear motion guides, so that there is a drawback that the sliding resistance is large and the yawing error is increased. Moreover, if the parallelism of the two linear motion guides is not maintained with high accuracy, there are disadvantages that the Y-axis moving body is deformed during movement, and that it does not move smoothly during movement.

  In addition, at the reference surface position for correcting the height from the surface of the probe, the reference surface defined by the linear motion guide in the Z direction of the probe and the reference surface to be measured, that is, the reference surface defined by the surface plate However, since it becomes a completely independent different reference plane, there is a drawback that it is not always possible to acquire a highly accurate Z displacement when the Y-axis moving body moves.

  Furthermore, since the gantry type CMM is provided with a pair of columns on the base, there is also a drawback that the visibility of the measurement area is poor.

  In addition, since the cantilever type three-dimensional measuring machine is configured such that the Y-axis moving body is cantilevered, there is a disadvantage that the rigidity is low and bending due to its own weight is likely to occur.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a three-dimensional measuring machine that has a small pitching error and yawing error and can perform high-accuracy measurement on a surface plate basis.

  Means for solving the problems are as follows.

  The first aspect includes a Y-axis guide means, a Y-axis moving body that is guided by the Y-axis guide means and moves in the Y-axis direction, an X-axis guide means provided in the Y-axis moving body, and an X-axis guide means An X-axis moving body that is guided and moves in the X-axis direction, a Z-axis guide means provided in the X-axis moving body, a Z-axis moving body that is guided by the Z-axis guide means and moves in the Z-axis direction, and a Z-axis A measuring unit provided in the moving body, and measuring the workpiece by moving the measuring unit in the X-axis, Y-axis, and Z-axis directions, the Y-axis guide means includes one piece parallel to the Y-axis. A guide rail, a slider provided on the guide rail so as to be slidable via a plurality of rolling elements, and connected to one end in the X-axis direction of the Y-axis moving body to guide the Y-axis moving body in the Y-axis direction; Attached to the guide surface parallel to the X-axis and the other end in the X-axis direction of the Y-axis moving body It is, to form an air film between the guide surface and air pad for slidably supported in a non-contact and the other end of the X-axis direction of the Y-axis moving body relative to the guide surface, a measuring machine comprising a.

  According to this aspect, one end of the Y-axis moving body is slidably supported on one guide rail via the slider, and the other end is supported to float on the guide surface via the air pad. As a result, the Y-axis moving body is supported so as to be swingable (turnable) around an axis parallel to the Y-axis around the support portion of the slider by the guide rail (being able to swing (rotate) in the rolling direction) Supported)). In other words, the Y-axis moving body can be flexibly swung (rotated) around the support portion of the slider. As a result, the air pad at the other end behaves based on the position of the measurement base on the guide surface with a constant drag, so that measurement in the Z direction can be performed with reference to the measurement base. This can also prevent the Y-axis moving body from being bent and deformed. That is, when the two guide rails are slidably supported via a slider, if the parallelism of the two guide rails is not maintained with high accuracy, deformation such as torsion occurs in the Y-axis moving body. One end is supported by a single guide rail and the other end is supported by levitating with an air pad, so that the difference in parallelism between the two can be determined by the movement of the Y-axis moving body ( It can be absorbed by rotational movement around a parallel axis (rotational movement in the rolling direction), and deformation of the Y-axis moving body can be prevented. Moreover, since both ends are supported, deformation due to its own weight such as cantilever support can be prevented. Thereby, measurement errors caused by deformation of the Y-axis moving body can be prevented.

  In addition, since one end is supported by one guide rail through the slider, the straightness for the Y-axis moving body to move on the Y-axis is defined by the slider on the guide rail. For this reason, it goes straight in the Y-axis direction with one guide rail as a reference, and does not swing left and right when moving in the Y-axis direction. Thereby, the displacement of a yawing direction can be suppressed. In general, levitation support by an air bearing makes it difficult to ensure straightness for moving the Y-axis moving body in the Y-axis direction, and the displacement in the yawing direction is large. For this reason, when both ends are levitated and supported by air bearings, the direction is slightly changed left and right with respect to the moving direction, and the displacement in the yawing direction increases. On the other hand, by supporting one end with a guide rail as in this mode, the straightness for moving the Y-axis moving body in the Y-axis direction is defined by the straightness of the guide rail based on the guide rail at one end. Can be made. For this reason, the Y-axis moving body moves straight on the basis of one guide rail. As a result, displacement in the yawing direction can be suppressed. Thereby, vibration in the yawing direction during acceleration / deceleration can be suppressed, and highly accurate measurement can be performed.

  Moreover, the consumption of compressed air can be suppressed by adopting a structure in which only one side is levitated and supported by an air pad. Thereby, running cost can be held down. Furthermore, the sliding resistance can be reduced by adopting a configuration in which it is supported by one guide rail. Thereby, the heat generation of the drive unit (motor) can be suppressed, and deformation of the base due to thermal stress can be suppressed.

  The second aspect is an aspect further comprising Y-axis driving means for driving the slider and moving the Y-axis moving body in the Y-axis direction in the measuring machine according to the first aspect.

  According to this aspect, the Y-axis drive means for driving the Y-axis moving body is disposed on the guide rail side instead of the air pad side. Thereby, the error due to yawing of the Y-axis moving body can be further reduced. That is, the sliding resistance is different between one slider portion and the other air pad portion, and the slider portion is much larger. When driving the Y-axis moving body, it is possible to move the Y-axis moving body straight on the basis of the straightness of the guide rail by providing the driving means on the slider side having a large sliding resistance. As a result, when the Y-axis moving body moves in the Y direction, the Y-axis moving body does not move while changing its direction slightly from side to side, and moves along the straightness of the guide rail. As a result, it is possible to further reduce errors due to yawing of the Y-axis moving body.

  The effect of this aspect is independent from the effect of the first aspect, that is, the effect of supporting the Y-axis moving body so as to be swingable (the effect of preventing the deformation of the Y-axis moving body). is there. This aspect has a mechanism for supporting a measuring part in a measuring machine having a measuring part at the center part, supporting one end with a slider that slides along the guide rail, and supporting the other end with an air pad. By providing the drive system on the slider side, there is an effect of reducing yawing (movement that moves while changing the direction alternately to the left and right) that occurs during movement. That is, in this aspect, when the Y-axis moving body is driven while taking into account the balance of sliding resistance and the balance of sliding resistance, it is allowed to go straight while reducing the moment of inertia that slightly changes the direction in the left-right direction. As a result, a unique effect of eliminating errors due to yawing is produced.

  As described above, when both ends of the Y-axis moving body are supported by air pads, the standard straightness cannot be ensured and there is no sliding resistance. There is a disadvantage that yawing becomes large. Similarly, when both ends are supported by a slider, if only one side is driven, the yawing error is further increased. In addition, if the parallelism is not achieved, there is a drawback that the movement itself is not smooth.

  A 3rd aspect is an aspect by which a guide rail is arrange | positioned upwards rather than a measurement part in the measuring machine of the 1st or 2nd aspect.

  The guide rail serves as a fulcrum that supports the Y-axis moving body. Strictly speaking, the fulcrum has two points: a guide rail part and a part of the guide surface that supports the air pad. However, since the air pad is not in contact with the surface plate, the point that substantially supports the Y-axis moving body is It becomes the guide rail part. On the other hand, the center-of-gravity position in the Y-axis movement is most preferably the measurement unit (near the tip of the probe when measuring with a probe) from the viewpoint of measurement error. However, strictly speaking, it is slightly above the measuring section. However, it is possible to position the center of gravity point below the fulcrum position of the guide rail. Since the position of the center of gravity is lower than the fulcrum position that is slid by such a drive mechanism, the entire Y-axis moving mechanism can be prevented from falling down. And by making it the structure which is hard to fall down in this way, the effect that the error (error which shakes in the front-back direction when moving) in a pitching direction can be remarkably reduced can be produced. As described above, by setting the position of the measurement unit (the position of the probe in the case of measuring with a probe) lower than the position of the guide rail serving as a fulcrum, the pitching error can be greatly reduced.

  A fourth aspect further includes a surface plate having a work placement surface parallel to the X axis and the Y axis in the measuring machine according to any one of the first to third aspects, wherein the work placement surface is a guide surface of an air pad. It is the aspect which serves as.

  According to this aspect, the surface plate for mounting a work is provided, and the work mounting surface of the surface plate is used as the guide surface of the air pad. Thereby, it is not necessary to provide a separate guide surface, and the configuration can be simplified. In general, since the work placement surface of the surface plate is flattened with high accuracy, the Y-axis moving body can be guided with high accuracy.

  In addition, the work placement surface of the surface plate is used as the guide surface of the air pad, thereby providing the following effects. The reference surface in the Z direction of the workpiece is based on the surface (upper surface) of the surface plate, that is, the workpiece placement surface (surface plate surface). When measuring with a probe, the height of the probe can be defined on the basis of the workpiece placement surface, with the probe brought into contact with the workpiece placement surface and the point of contact as 0 point. On the other hand, the reference surface of the Y-axis moving body including the probe is also a workpiece placement surface. The Y-axis moving body is configured to constantly move up and down based on the workpiece placement surface by the flying force of the air pad, and the guide rail side, which is one of the support points, swings (rotates) around the center of the guide rail. It is configured to move. For example, even if the parallelism between the guide rail and the surface plate is not ensured, the Y-axis moving body is lifted with reference to the workpiece placement surface under a constant levitation force formed by the air pad, and the guide rail portion Is adjusted by swinging (turning) and follows the Y-axis moving body without being bent and deformed. Therefore, since two of the workpiece and the probe are based on the workpiece placement surface, it is possible to accurately measure under the same reference surface.

  Also, since the measurement reference surface is defined as one surface for both the workpiece and the probe, control and management can be facilitated, and even if there is a minute aging of the device, by configuring sequentially, High-accuracy measurement can be secured over a long period of time.

  Furthermore, when the guide rail is disposed above the measurement unit, the following effects are obtained. When the guide rail is arranged above the measurement unit, the workpiece measurement site is approximately halfway between the two fulcrums (the surface plate facing the guide rail and the air pad) that support the Y-axis moving body in the Z and X directions. Will be in position. The presence of the workpiece measurement part at approximately the middle position between the two fulcrums in this way cancels out or at least reduces the minute vibrations and minute displacements at the respective fulcrum parts without being promoted. Will be. In the case of a bridge-type measuring machine or a gantry-type measuring machine, the workpiece measurement site exists farther than the positions of the two fulcrums. Therefore, there is a problem that a slight vibration of the fulcrum part is promoted by the moment, resulting in a larger error. However, according to this aspect, the problem that vibration and displacement are promoted in this way does not occur.

  According to a fourth aspect, in the measuring instrument according to any one of the first to third aspects, the Y-axis moving body includes a leg portion parallel to the Z axis, and an X axis extending in parallel with the X axis from the upper end portion of the leg portion. It has an L-shape consisting of a base part, a slider is connected to the tip part of the X-axis base part, an air pad is attached to the lower end part of the leg part, and an X-axis guide means is provided on the X-axis base part. is there.

  According to this aspect, the Y-axis moving body has an L-shape composed of the X-axis base portion and the leg portion. The Y-axis moving body is supported by a slider connected to the tip of the X-axis base and an air pad attached to the lower end of the leg so as to be movable in the Y-axis direction. By making it L-shaped, the moving part can be reduced in weight compared to the bridge type. Thereby, the moment of inertia at the time of acceleration / deceleration can be reduced, and the displacement (vibration) in the dynamic pitching direction can be reduced. Moreover, the visibility of the measurement area can be improved.

  A sixth aspect is the measuring machine according to the fifth aspect, further comprising: a Y-axis base provided with a guide rail; and a V-shaped Y-axis column provided on the surface plate and supporting the Y-axis base. It is.

  According to this aspect, the Y-axis base on which the guide rail is disposed is installed on the surface plate via the V-shaped Y-axis column. Thereby, the visibility of a measurement area can be improved. In general, the surface plate is made of stone and the Y-axis column is made of metal (mainly made of cast iron). The installation area of the shaft column can be minimized. Thereby, the influence of a bimetal can be suppressed to the minimum.

  According to a seventh aspect, in the measuring instrument according to any one of the first to third aspects, the Y-axis moving body includes an X-axis base portion parallel to the X-axis, and parallel to the Z-axis from both ends of the X-axis base portion. It has a gate shape consisting of a pair of extending leg parts, a slider is connected to the lower end part of one leg part, an air pad is attached to the lower end part of the other leg part, and an X-axis guide means is provided on the X-axis base part. It is an aspect provided.

  According to this aspect, the Y-axis moving body has a gate shape. Thereby, the visibility of a measurement area can be improved.

  The eighth aspect is an aspect in which the measuring machine according to the seventh aspect further includes a surface plate having a work placement surface parallel to the X axis and the Y axis, and the work placement surface also serves as a guide surface.

  According to this aspect, the surface plate for mounting a work is provided, and the work mounting surface of the surface plate is used as the guide surface of the air pad. Thereby, it is not necessary to provide a separate guide surface, and the configuration can be simplified. In general, since the work placement surface of the surface plate is flattened with high accuracy, the Y-axis moving body can be guided with high accuracy.

  According to a ninth aspect, in the measuring machine according to any one of the first to third aspects, a first Y-axis base provided with a surface plate having a workpiece placement surface parallel to the X-axis and the Y-axis, and a guide rail A first Y-axis column that is provided on the surface plate and supports the first Y-axis base, a second Y-axis base having a guide surface, and a second Y-axis base that is provided on the surface plate. And a second Y-axis column to be supported, and the Y-axis moving body has a bar shape.

  According to this aspect, the Y-axis moving body has a bar shape. As a result, the Y-axis moving body can be made the minimum necessary size, that is, the minimum size that can ensure the movement of the X-axis moving body. Thereby, a moving part can be reduced in weight and the moment of inertia at the time of acceleration / deceleration can be reduced.

  A tenth aspect is an aspect in which the air pad is attached to the Y-axis moving body via a free joint in the measuring instrument according to any one of the first to ninth aspects.

  According to this aspect, the air pad is attached to the Y-axis moving body via the free joint. Thereby, even when the guide surface has a undulation, the air pad can swing along the undulation and the Y-axis moving body can be prevented from receiving a torsional moment.

  In an eleventh aspect, in a moving guide mechanism of a measuring machine that guides a moving body on which a measuring unit is mounted along a horizontal axis, there is one guide rail disposed parallel to the axis, and a plurality of guide rails. The movable body is slidable through the rolling element, and one end of the movable body is connected to the slider, which guides the movable body along the axis, a horizontal guide surface, and the other end of the movable body. And an air pad that slidably supports the other end of the movable body in a non-contact manner with respect to the guide surface.

  According to this aspect, one end of the moving body is slidably supported on one guide rail via the slider, and the other end is supported to float on the guide surface via the air pad. As a result, the moving body is supported so as to be able to swing around an axis parallel to the Y-axis (supported so as to be swingable in the rolling direction) starting from the support portion of the slider by the guide rail. As described above, the movable body can be prevented from being deformed by enabling flexible swinging with respect to the movable body. Moreover, since both ends are supported, deformation due to its own weight can be prevented. Thereby, the measurement error which arises by deformation | transformation of a moving body can be prevented. Further, since one end is supported by one guide rail via a slider, displacement in the yawing direction can be suppressed. Thereby, vibration in the yawing direction during acceleration / deceleration can be suppressed, and highly accurate measurement can be performed. Moreover, the consumption of compressed air can be suppressed by adopting a structure in which only one side is levitated and supported by an air pad. Thereby, running cost can be held down. Furthermore, the sliding resistance can be reduced by adopting a configuration in which it is supported by one guide rail. Thereby, the heat generation of the drive unit (motor) can be suppressed, and deformation of the base due to thermal stress can be suppressed.

  According to a twelfth aspect, in the movement guide mechanism of the measuring machine according to the eleventh aspect, the moving body has an L shape including a leg portion and a base portion, and a slider is connected to the tip portion of the base portion. This is an aspect in which an air pad is attached to the lower end part of the part and the measurement part is mounted on the base part.

  According to this aspect, the moving body has an L shape. Thereby, compared with a bridge | bridging type | mold, a moving part can be reduced in weight and the moment of inertia at the time of acceleration / deceleration can be reduced. Moreover, the visibility of the measurement area can be improved.

  In a thirteenth aspect, in a movement guide mechanism of a measuring machine that guides a moving body on which a measurement unit is mounted along a horizontal axis, one end of the moving body is supported and the moving body is linearly guided along the axis. A moving guide mechanism of a measuring machine including one mechanical linear guide bearing and at least one air bearing that levitates and supports the other end of the moving body.

  According to this aspect, one end of the moving body is supported by the linear motion guide bearing, and the other end is supported by the air bearing. As a result, the moving body can be supported by the linear motion guide bearing so as to be swingable (supported so as to be swingable in the rolling direction), and deformation of the moving body can be prevented. Moreover, since both ends are supported, deformation due to its own weight can be prevented. Thereby, the measurement error which arises by deformation | transformation of a moving body can be prevented. Further, since one end is supported by the linear motion guide bearing, the displacement in the yawing direction can be suppressed. Thereby, the vibration of the yawing direction at the time of acceleration / deceleration can be suppressed. Moreover, the consumption of compressed air can be suppressed by adopting a structure in which only one side is levitated and supported by an air bearing. Thereby, running cost can be held down. Furthermore, the sliding resistance can be reduced by adopting a configuration in which it is supported by one linear motion guide bearing. Thereby, the heat generation of the drive unit (motor) can be suppressed, and deformation of the base due to thermal stress can be suppressed.

  A fourteenth aspect is the movement guide mechanism of the measuring instrument according to the thirteenth aspect, wherein the moving body has an L-shape consisting of a leg portion and a base portion, and the tip portion of the base portion is supported by the linear motion guide bearing. The lower end portion of the leg portion is supported by the air bearing, and the measurement portion is mounted on the base portion.

  According to this aspect, the moving body has an L shape. Thereby, compared with a bridge | bridging type | mold, a moving part can be reduced in weight and the moment of inertia at the time of acceleration / deceleration can be reduced. Moreover, the visibility of the measurement area can be improved.

  According to the present invention, it is possible to perform highly accurate measurement while suppressing running cost. In addition, a highly visible measuring machine can be configured.

The front view which shows 1st Embodiment of the measuring device which concerns on this invention. Left side view of the measuring machine shown in FIG. Right side view of the measuring machine shown in FIG. Plan view of the measuring machine shown in FIG. The perspective view which shows the structure of a linear guide 6-6 sectional view of FIG. Explanatory drawing of the effect | action of the measuring machine which concerns on this invention The front view which shows 2nd Embodiment of the measuring machine which concerns on this invention. Right side view of the measuring machine shown in FIG. The front view which shows 3rd Embodiment of the measuring device which concerns on this invention. Left side view of the measuring machine shown in FIG. Front view showing schematic configuration of conventional measuring machine

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

<< First Embodiment >>
<Device configuration>
FIG. 1 is a front view showing a first embodiment of a measuring instrument according to the present invention, and FIGS. 2, 3, and 4 are a left side view, a right side view, and a plan view of the measuring instrument shown in FIG. 1, respectively. It is.

  This measuring machine 10 is a so-called three-dimensional measuring machine, and measures the shape, dimensions, etc. of a workpiece using probes provided so as to be movable in the directions of the X, Y, and Z axes orthogonal to each other. .

  In the present embodiment, the X axis and the Y axis constitute a horizontal axis, and the Z axis constitutes a vertical axis. Therefore, the surface formed by the X axis and the Y axis forms a horizontal surface, and the surface formed by the X axis and the Z axis and the surface formed by the Y axis and the Z axis form a vertical surface.

  The measuring machine 10 mainly includes a gantry (base) 12, a surface plate 14 provided on the gantry 12, a Y-axis column 16 provided on the surface plate 14, and a Y-axis base 18 supported by the Y-axis column 16. A Y-axis guide mechanism 20 provided in the Y-axis base 18, a Y-axis moving frame (Y-axis moving body) 22 that is guided by the Y-axis guide mechanism 20 and moves along the Y-axis, and a Y-axis moving frame 22 Along the Y axis, a Y axis drive unit (Y axis drive means) 24, an X axis guide mechanism 26 provided in the Y axis movement frame 22, and an X axis guide mechanism 26 guided along the X axis. An X-axis moving frame (X-axis moving body) 28 that moves, an X-axis driving unit (X-axis driving means) 30 that moves the X-axis moving frame 28 along the X-axis, and a Z provided in the X-axis moving frame 28 Shaft guide mechanism 32 and A Z-axis moving frame (Z-axis moving body) 34 that is guided by the Z-axis guide mechanism 32 and moves along the Z-axis, a Z-axis drive unit 36 that moves the Z-axis moving frame 34 along the Z-axis, and Z And a measuring unit 38 provided in the shaft moving frame 34.

  The gantry 12 supports the surface plate 14 horizontally. The gantry 12 includes three fixing legs 12A and two fall prevention legs 12B. The three fixing legs 12A are arranged at the respective vertex positions of the triangle, and two of the fixing legs 12A are arranged at the front and rear corners on the right side of the surface plate 14. The remaining one fixing leg 12 </ b> A is arranged at the center of the left side of the surface plate 14. The two fall prevention legs 12 </ b> B are arranged at the front and rear corners on the left side of the surface plate 14.

  At the tip of each fixing leg 12A, a foot 12a whose height is adjustable is provided. Similarly, the tip of each fall prevention leg 12B is provided with a foot 12b whose height can be adjusted.

  The surface plate 14 is a flat plate whose surface is finished correctly and smoothly. The workpiece to be measured is placed on the surface plate 14. In measuring machine 10 of the present embodiment, surface plate 14 is formed in a rectangular shape. The X axis and the Y axis are set parallel to the upper surface (work placement surface (surface plate surface)) 14A of the surface plate 14, and the Z axis is set perpendicular to the upper surface (work placement surface 14A) of the surface plate 14. Is done. The X axis is set parallel to the front and back sides of the surface plate 14, and the Y axis is set parallel to the left and right sides of the surface plate 14.

  The surface plate 14 is preferably made of a stone material (for example, artificial marble) in order to prevent deformation due to heat or the like.

  The Y-axis column 16 is installed on the surface plate 14 and supports the Y-axis base 18 at a predetermined height from the surface plate 14. The Y-axis column 16 includes a base portion 16A and two support column portions 16B extending upward from both ends of the base portion 16A, and is formed in a V shape as a whole. That is, the two support columns 16B are arranged so as to expand outward from the base 16A and are formed in a V shape. The Y-axis column 16 is installed on the surface plate 14 by fixing the base portion 16A to the surface plate 14, and is arranged vertically along the Y-axis.

  The Y-axis column 16 is made of cast iron, for example. When the Y-axis column 16 is made of cast iron, the influence of bimetal due to temperature changes becomes a problem with the surface plate 14 made of stone. However, since the Y-axis column 16 of this example is formed in a V shape, the installation area with the surface plate 14 can be suppressed. Thereby, the influence of a bimetal can be suppressed to the minimum. Further, by making the Y-axis column 16 V-shaped, lateral visibility (visibility as viewed from the installation side of the Y-axis column 16) can be ensured.

  The Y-axis base 18 is formed in a prismatic shape. The Y-axis base 18 is supported by the Y-axis column 16 and is disposed at a predetermined height from the surface plate 14. The Y-axis base 18 is disposed along the Y-axis.

  The Y-axis base 18 is made of cast iron, for example. Note that the Y-axis base 18 and the Y-axis column 16 can be configured integrally.

  The Y-axis guide mechanism 20 supports a Y-axis moving frame (Y-axis moving body) 22 so as to be movable along the Y-axis. The Y-axis guide mechanism 20 includes a Y-axis table 42 and a Y-axis linear motion guide 44 that supports the Y-axis table 42 movably along the Y axis.

  The Y-axis linear motion guide 44 is a so-called mechanical linear motion guide bearing (also referred to as a linear guide or an LM guide (trademark)).

  FIG. 5 is a perspective view showing the configuration of the linear motion guide. 6 is a cross-sectional view taken along the line 6-6 in FIG.

  As shown in the figure, the Y-axis linear motion guide 44 is slidably supported by the Y-axis guide rail 46 via a single Y-axis guide rail 46 extending linearly and a plurality of balls (rolling elements) 48. And a Y-axis slider 50.

The Y-axis guide rail 46 includes a base portion 46A, a support portion 46B, and a rail portion 46C, and has a substantially I-shaped cross section. The base 46A is an installation part to the Y-axis base 18. The Y-axis guide rail 46 has a structure in which the rail portion 46C is supported by the base portion 46A via a support portion 46B. The support portion 46B is thinner than the base portion 46A and the rail portion 46C. As a result, the Y-axis guide rail 46 is formed in a substantially I-shaped cross section as a whole.

  The rail portion 46C of the Y-axis guide rail 46 is provided with a ball rolling surface 52 on which the ball 48 rolls. In the Y-axis linear motion guide 44 of the present embodiment, a total of four ball rolling surfaces 52 are provided, two on each side of the rail portion 46C. Each ball rolling surface 52 is formed along the axis of the Y-axis guide rail 46, and is inclined with respect to the bottom surface of the Y-axis guide rail 46 (the bottom surface of the base 46A) at an angle of 45 °.

  The Y-axis slider 50 is configured as a block body having a substantially U-shaped cross section, and is assembled to the Y-axis guide rail 46 so as to straddle the Y-axis guide rail 46. The Y-axis slider 50 is provided with an infinite circulation path for balls 48 that are rolling elements. The Y-axis slider 50 is slidably supported with respect to the Y-axis guide rail 46 by the balls 48 circulating in the infinite circulation path.

  The Y-axis slider 50 includes a slider main body 54 and a pair of end plates 56 attached to both front and rear end surfaces in the axial direction (sliding direction) of the slider main body 54.

  The slider main body 54 includes a main beam portion 54A and a pair of leg portions 54B, and is configured as a block body having a substantially U-shaped cross section as a whole.

  The main beam portion 54A is formed in a rectangular flat plate shape, and the upper surface portion functions as a mounting surface of the Y-axis table 42.

  The pair of leg portions 54B are disposed on both the left and right sides of the main beam portion 54A. A load rolling surface 58 on which the ball 48 rolls is provided inside each leg 54B. The load rolling surface 58 is provided corresponding to the ball rolling surface 52 on the guide rail side. That is, when the Y-axis slider 50 is assembled to the Y-axis guide rail 46, the Y-axis slider 50 is disposed so as to face the ball rolling surface 52 provided on the Y-axis guide rail 46. The Y-axis linear motion guide 44 of the present embodiment is provided with a total of four ball rolling surfaces 52, two on each side of the rail portion 46C of the Y-axis guide rail 46. For this reason, the Y-axis slider 50 is also provided with a total of four load rolling surfaces 58, two on the inner side of each leg portion 54B.

  As described above, the load rolling surface 58 of the slider body 54 is disposed so as to face the ball rolling surface 52 on the guide rail side when the Y-axis slider 50 is assembled to the Y-axis guide rail 46. . Thereby, a load passage 60 for the ball 48 is formed between the Y-axis guide rail 46 and the Y-axis slider 50. The ball 48 rolls in the load passage 60 while applying a load between the Y-axis slider 50 and the Y-axis guide rail 46.

  Here, the cross-sectional shape of each load rolling surface 58 (the cross-sectional shape in the direction orthogonal to the axial direction) is formed in a circular arc shape having a curvature radius slightly larger than the curvature radius of the spherical surface of the ball 48. However, the design of this shape can be changed as appropriate. The ball rolling surface 52 provided in the Y-axis guide rail 46 is similarly formed in a circular arc shape.

  Each leg 54B is provided with a ball return passage 62 corresponding to each load passage 60 (a total of four ball return passages 62 are provided in one slider body 54, two for each leg 54B. ). The ball return passage 62 has a circular cross section and is formed in parallel with the load passage. The inner diameter of the ball return passage 62 is formed larger than the outer diameter of the ball 48 so that the ball 48 can roll while being released from the load.

  The end plate 56 is formed corresponding to the shape of the slider body 54 and has a substantially U-shaped cross section. The end plate 56 is provided with a direction changing path (not shown) corresponding to each ball return path 62 of the slider body 54 (two directions on the left and right, a total of four direction changing paths on one end plate 56. Provided.). The direction change path is formed in a U-shape, and the ball return path 62 and the load path 60 of the slider body 54 are communicated with each other by attaching the end plate 56 to the slider body 54. Thereby, an infinite circulation path of the ball 48 is formed.

  The ball 48 contacts the ball rolling surface 52 of the Y-axis guide rail 46 and the load rolling surface 58 of the Y-axis slider 50 in the load passage 60 and acts between the Y-axis guide rail 46 and the Y-axis slider 50. The load passage 60 rolls while applying a load.

  When the Y-axis slider 50 moves on the Y-axis guide rail 46, the ball 48 rolls in the load passage 60 in the direction opposite to the moving direction of the Y-axis slider 50. And if it rolls off from the terminal end of the load channel | path 60, it will be released | released from a load and will approach into a direction change path (not shown) in an unloaded state. The ball 48 that has entered the direction change path is guided to the direction change path, changes its traveling direction by 180 °, and enters the ball return path 62. After the ball 48 travels in the ball return passage 62 in an unloaded state, the ball 48 enters the direction change path again, changes its traveling direction by 180 °, and enters the load passage 60. Then, the load passage 60 rolls while applying a load acting between the Y-axis guide rail 46 and the Y-axis slider 50 again. In this way, the ball 48 circulates in the infinite circuit while alternately repeating the load state and the no-load state. As a result, the Y-axis slider 50 can smoothly slide along the Y-axis guide rail 46.

  In the Y-axis linear motion guide 44 of the present embodiment, a ball is used as the rolling element, but a roller or the like can be used as the rolling element.

  Further, in the Y-axis linear motion guide 44 of the present embodiment, the infinite circulation path in which the ball rolls is configured in four rows, but the number of rows in the infinite circulation path is not limited to this. Absent. For example, the endless circuit may be arranged in two rows.

  In the Y-axis linear guide 44 configured as described above, the Y-axis guide rail 46 is laid on the Y-axis base 18 along the Y-axis. Therefore, the Y-axis slider 50 is supported so as to be movable along the Y-axis.

  In the Y-axis linear motion guide 44 of the present embodiment, two Y-axis sliders 50 are supported on one Y-axis guide rail 46 (only one slider is shown in FIG. 5).

  The Y-axis table 42 is formed in a rectangular flat plate shape. The Y-axis table 42 is fixed to the Y-axis slider 50 and installed horizontally (installed in parallel with the XY plane). Therefore, the Y-axis table 42 is slidably supported in a horizontal posture along the Y-axis direction.

  The Y-axis moving frame 22 is guided by the Y-axis guide mechanism 20 and moves along the Y-axis. The Y-axis moving frame 22 is formed in an L shape having a horizontal beam portion 22A and a vertical column portion 22B, and is arranged vertically along the X axis (arranged along the XZ plane). .)

  The beam portion 22A is formed in a substantially prismatic shape and is disposed along the X axis. The column portion 22B is formed in a substantially prismatic shape and is disposed along the Z axis. The column portion 22B is connected to and integrated with one end of the beam portion 22A at the upper end portion. As a result, the L-shaped Y-axis moving frame 22 is formed as a whole.

  The Y-axis moving frame 22 is supported at the tip end of the beam portion 22A by being fixed to a Y-axis table 42 so as to be slidable in the Y-axis direction. Further, the lower end of the column portion 22 </ b> B of the Y-axis moving frame 22 is levitated and supported on the surface plate 14 by the air bearing 70.

  The air bearing 70 includes an air pad 72, and supports the column portion 22 </ b> B of the Y-axis moving frame 22 in a floating manner using the upper surface (work placement surface) 14 </ b> A of the surface plate 14 as a guide surface.

  The air pad 72 is formed in a disk shape, and is attached to the lower end portion of the column portion 22B. The air pad 72 injects compressed air toward the upper surface of the surface plate 14 (work placement surface 14A), thereby forming an air layer between the upper surface of the surface plate 14 and the column 22B. Levitates and supports the top surface of

  In this example, the air pad 72 is attached to the lower end portion of the column portion 22B via a universal joint 74. That is, the air pad 72 is attached to the lower end portion of the support column portion 22B in a swingable state. By attaching the air pad 72 to the column portion 22B through the universal joint 74 as described above, even if the upper surface (guide surface) 14A of the surface plate 14 has a undulation, the air pad 72 swings along the undulation. It is possible to prevent the Y-axis moving frame 22 from receiving a torsional moment.

  As described above, one end (the tip of the beam portion 22A) of the Y-axis moving frame 22 is supported slidably along the Y-axis direction by one Y-axis linear motion guide 44, and the other end (the lower end of the column portion 22B). ) Is levitated and supported on the surface plate 14 by the air bearing 70, and is supported so as to be movable along the Y axis. By supporting the Y-axis moving frame 22 with such a structure, the Y-axis moving frame 22 can be moved with high accuracy by preventing deformation (twisting, bending, etc.) of the Y-axis moving frame 22. This is due to the following mechanism.

  The Y-axis moving frame 22 supports the X-axis moving frame 28 so as to be movable in the X-axis direction. For this reason, it is necessary to ensure the length of the beam portion 22A at least for the movement stroke of the X-axis movement frame 28. Further, when both ends of the beam portion 22A are supported by the linear motion guide (mechanical linear motion guide bearing) and the air bearing, it is necessary to secure the installation interval between the both by the travel stroke of the X-axis moving frame 28. . When the linear motion guide and the air bearing are separated from each other as described above, if the parallelism between the two is not maintained with high accuracy, a moment in the rolling direction (moment about the Y axis) is generated on the Y axis moving frame 22. Occur.

  Consider a case where both ends of the Y-axis moving frame 22 are supported by linear motion guides (mechanical linear motion guide bearings). In this case, the moment generated in the Y-axis moving frame 22 directly acts on the Y-axis moving frame 22 as a bending moment. As a result, the Y-axis moving frame 22 is deformed.

  Similarly, when one end supports the air bearing and the other end is supported by a pair of linear motion guides, the moment acts directly on the Y-axis moving frame 22 as a bending moment. As a result, the Y-axis moving frame 22 is deformed.

  On the other hand, when one end is supported by one Y-axis linear motion guide 44 and the other end is supported by the air bearing 70 as in the present embodiment, the moment generated in the Y-axis moving frame 22 is Y It is absorbed by the shaft linear motion guide 44.

  In general, linear motion guides (mechanical linear motion guide bearings) are strong against load moments in the pitching direction (MP direction in FIG. 5) and yawing direction (MY direction in FIG. 5) due to their structure, but in the rolling direction (see FIG. 5). (5 MR direction) has a characteristic of being weak. Therefore, when one end is supported by one Y-axis linear motion guide 44 and the other end is supported by an air bearing 70, the Y-axis moving frame 22 is flexible in the rolling direction (MR) as shown in FIG. Movement becomes possible. As a result, even when a moment in the rolling direction is generated in the Y-axis moving frame 22, no load is applied to the Y-axis moving frame 22, and deformation is prevented.

  Moreover, according to this structure, since both ends of the Y-axis moving frame 22 are supported, deformation due to its own weight can be prevented like cantilever support.

  In general, the levitation support by the air bearing has a drawback that the displacement in the yawing direction is large, but by supporting one end with the Y-axis linear motion guide 44, the displacement in the yawing direction can also be suppressed. That is, as described above, the linear motion guide has a characteristic that it is strong against load moments in the pitching direction and yawing direction (because it is a mechanical linear motion guide bearing under pressure, the yawing rigidity However, by supporting one end with the Y-axis linear motion guide 44, displacement in the yawing direction can be effectively suppressed even when one side is supported with an air bearing.

  Furthermore, the consumption of compressed air can also be suppressed by adopting a configuration in which only one side is levitated and supported by the air bearing 70.

  Thus, by making good use of the characteristics of the air bearing and the linear guide, the Y-axis moving frame 22 can be supported movably along the Y-axis without causing deformation.

  The Y-axis drive unit 24 drives the Y-axis moving frame 22 by so-called belt drive. The Y-axis drive unit 24 includes a pair of pulleys 76A and 76B, a drive belt 78 wound around the pair of pulleys 76A and 76B, and a Y-axis motor 80 that rotationally drives one pulley 76A.

  The pair of pulleys 76A and 76B are installed on the Y-axis base 18 via brackets 82A and 82B, respectively. The rotation axes of the pulleys 76A and 76B are arranged in parallel with the X axis.

  The drive belt 78 is formed in an endless shape. The drive belt 78 is disposed along the Y axis by being wound around the pair of pulleys 76A and 76B.

  Here, the drive belt 78 is disposed on the same straight line as the Y-axis guide rail 46 of the Y-axis linear motion guide 44. That is, the Y-axis guide rail 46 is disposed so as to overlap. Thus, by arranging the drive belt 78, the drive point can be arranged on the line that receives the sliding resistance, and the hysteresis of the reciprocating movement can be eliminated.

  In addition, in order to arrange the drive belt 78 in this way, the pair of pulleys 76 </ b> A and 76 </ b> B are arranged before and after the Y-axis linear motion guide 44. Further, the Y-axis moving frame 22 is provided with an insertion hole 84 through which the drive belt 78 is passed.

  The Y-axis motor 80 rotationally drives one pulley 76A and causes the drive belt 78 to travel. The Y-axis motor 80 is attached to the bracket 82A and connected to the pulley 76A.

  The Y-axis drive unit 24 configured as described above drives the Y-axis motor 80 so that the drive belt 78 travels along the Y-axis direction. The drive belt 78 is connected to the Y-axis table 42. Thus, when the Y-axis motor 80 is driven, the Y-axis table 42 moves along the Y axis. Further, when the Y-axis table 42 moves along the Y-axis, the Y-axis moving frame 22 moves along the Y-axis.

  The X-axis guide mechanism 26 supports the X-axis moving frame 28 so as to be movable along the X-axis. The X-axis guide mechanism 26 includes an X-axis table 86 and a pair of X-axis linear motion guides 88 that guide the X-axis table 86 along the X-axis direction.

  The configuration of the X-axis linear motion guide 88 is the same as the configuration of the Y-axis linear motion guide 44 that constitutes the Y-axis guide mechanism 20. That is, an X-axis guide rail 90 and an X-axis slider 92 that is slidably supported by the X-axis guide rail 90 via a plurality of balls (not shown) are configured. The X-axis guide rail 90 is laid on the beam portion 22A of the Y-axis moving frame 22, and is disposed along the X-axis.

  The X-axis table 86 is formed in a rectangular flat plate shape. The X-axis table 86 is fixed to the X-axis slider 92 of each X-axis linear motion guide 88 and installed horizontally (installed parallel to the XY plane). Therefore, the X-axis table 86 is slidably supported in a horizontal posture along the X-axis direction.

  The X-axis moving frame 28 is formed in a prismatic shape. The X-axis moving frame 28 is vertically attached to the X-axis table 86.

  The X-axis moving frame 28 is movably supported by the pair of X-axis linear motion guides 88. However, since the installation interval between the pair of X-axis linear motion guides 88 is short, deformation of the X-axis moving frame 28 is a problem. Never become.

  The X-axis drive unit 30 moves the X-axis moving frame 28 with a so-called feed screw. The X-axis drive unit 30 includes a screw rod 94, a nut member 96 that is screwed to the screw rod 94, and an X-axis motor 98 that rotationally drives the screw rod 94.

  The screw rod 94 is rotatably attached to the beam portion 22A of the Y-axis moving frame 22 via the pair of brackets 100. The screw rod 94 is disposed along the X axis. The screw rod 94 is disposed between the pair of X-axis linear motion guides 88.

  The nut member 96 is screwed onto the screw rod 94. The nut member 96 is connected to the X-axis table 86. Therefore, when the screw rod 94 is rotated, the X-axis table 86 moves along the X-axis direction according to the rotation amount.

  The X-axis motor 98 is connected to the screw rod 94 and rotationally drives the screw rod 94. The X-axis motor 98 is attached to one bracket 100 and connected to the screw rod 94.

  In the X-axis drive unit 30 configured as described above, when the X-axis motor 98 is driven, the screw rod 94 rotates, and the X-axis table 86 moves along the X-axis direction according to the rotation amount. As a result, the X-axis moving frame 28 provided on the X-axis table 86 moves along the X-axis direction.

  The Z-axis guide mechanism 32 supports the Z-axis moving frame 34 so as to be movable along the Z-axis. The Z-axis guide mechanism 32 includes a Z-axis table 102 and a pair of Z-axis linear motion guides 104 that guide the Z-axis table 102 along the Z-axis direction.

  The configuration of the Z-axis linear motion guide 104 is the same as the configuration of the Y-axis linear motion guide 44 that constitutes the Y-axis guide mechanism 20. That is, the Z-axis guide rail 106 and a Z-axis slider 108 that is slidably supported by the Z-axis guide rail 106 via a plurality of balls (not shown) are configured. The Z-axis guide rail 106 is laid on the X-axis moving frame 28 and disposed along the Z-axis.

  The Z-axis table 102 is formed in a rectangular flat plate shape. The Z-axis table 102 is fixed to the Z-axis slider 108 of each Z-axis linear motion guide 104 and installed vertically (installed parallel to the XZ plane). Therefore, the Z-axis table 102 is slidably supported along the XZ plane.

  The Z-axis moving frame 34 is formed in a prismatic shape. The Z-axis moving frame 34 is attached to the Z-axis table 102 along the Z axis and is supported so as to be movable along the Z axis.

  The Z-axis moving frame 34 is movably supported by the pair of Z-axis linear motion guides 104. However, since the installation interval between the pair of Z-axis linear motion guides 104 is short, deformation of the Z-axis moving frame 34 is a problem. Never become.

  The Z-axis drive unit 36 moves the Z-axis moving frame 34 along the Z-axis with a so-called feed screw. The Z-axis drive unit 36 includes a screw rod 110, a nut member 112 that is screwed to the screw rod 110, and a Z-axis motor 114 that rotationally drives the screw rod 110.

  The screw rod 110 is rotatably attached to the X-axis moving frame 28 via a pair of brackets 116. The screw rod 110 is disposed along the Z axis. The screw rod 110 is disposed between the pair of Z-axis linear motion guides 104.

  The nut member 112 is screwed onto the screw rod 110. The nut member 112 is connected to the Z-axis table 102. Therefore, when the screw rod 110 is rotated, the Z-axis table 102 moves along the Z-axis direction according to the amount of rotation.

  The Z-axis motor 114 is connected to the screw rod 110 and rotationally drives the screw rod 110. The Z-axis motor 114 is attached to one bracket 116 and connected to the screw rod 110.

  In the Z-axis drive unit 36 configured as described above, when the Z-axis motor 114 is driven, the screw rod 110 rotates, and the Z-axis table 102 moves along the Z-axis direction according to the amount of rotation. As a result, the Z-axis moving frame 34 provided on the Z-axis table 102 moves along the Z-axis direction.

  The measuring unit 38 is provided in the Z-axis moving frame 34. The measurement unit 38 includes a measurement unit main body 118 and a probe 120. The measurement unit main body 118 is formed in a box shape and incorporates a probe control device (not shown). The probe 120 is disposed vertically downward from the measurement unit main body 118 along the Z axis. When the Z-axis moving frame 34 is moved, the probe 120 moves along the Z-axis direction. During measurement, the tip of the probe 120 is brought into contact with the workpiece to be measured, the coordinates (X, Y, Z) of the tip at the time of contact are detected, and the shape, dimensions, etc. of the workpiece are measured from the set of coordinate values. To do.

  The Y-axis base 18 is provided with a scale (Y-axis scale) (not shown) for detecting the position of the Y-axis moving frame 22 on the Y-axis along the Y-axis. The Y-axis coordinates of the probe 120 are obtained by detecting the position of the Y-axis moving frame 22 using this Y-axis scale.

  The beam portion 22A of the Y-axis moving frame 22 is provided with a scale (X-axis scale) (not shown) for detecting the position of the X-axis moving frame 28 on the X-axis along the X-axis. The X-axis coordinates of the probe 120 are obtained by detecting the position of the X-axis moving frame 28 using this X-axis scale.

  Further, the X-axis moving frame 28 is provided with a scale (Z-axis scale) (not shown) for detecting the position of the Z-axis moving frame 34 on the Z-axis along the Z-axis. The Z-axis coordinates of the probe 120 are obtained by detecting the position of the Z-axis moving frame 34 using this Z-axis scale.

<Action>
As described above, the measuring instrument 10 according to the present embodiment is configured as a three-dimensional measuring instrument, and measures the shape, dimensions, and the like of a workpiece (measurement object).

  As shown in FIG. 7, the workpiece W is placed on the surface plate 14.

  The measurement is performed by bringing the tip of the probe 120 into contact with the surface of the workpiece W. That is, by moving the probe 120, the coordinates (X, Y, Z) when the tip of the probe 120 contacts the workpiece W are detected, and the shape, dimension, etc. of the workpiece are measured from the set of coordinate values.

  The probe 120 moves along the X, Y, and Z axes by driving the X-axis motor 98, the Y-axis motor 80, and the Z-axis motor 114. That is, when the X-axis motor 98 is driven, the X-axis moving frame 28 moves along the X axis, and as a result, the probe 120 moves along the X axis. When the Y-axis motor 80 is driven, the Y-axis moving frame 22 moves along the Y axis, and as a result, the probe 120 moves along the Y axis. When the Z-axis motor 114 is driven, the Z-axis moving frame 34 moves along the Z-axis, and as a result, the probe 120 moves along the Z-axis.

  At this time, since the Y-axis moving frame 22 on which the X-axis moving frame 28 and the Z-axis moving frame 34 are mounted is movably supported by one Y-axis linear motion guide 44 and the air bearing 70, high accuracy is achieved. The probe 120 can be moved.

  That is, as described above, if the Y-axis linear motion guide 44 and the air bearing 70 are installed apart from each other in order to support the Y-axis movement frame 22 so as to be movable along the Y-axis, Although a moment in the rolling direction is generated, the Y-axis moving frame 22 can move flexibly in the rolling direction (MR) (can swing around the Y-axis). Even when a directional moment is generated, the Y-axis moving frame 22 is supported without being deformed. Thereby, the Y-axis moving frame 22 on which the X-axis moving frame 28 and the Z-axis moving frame 34 are mounted can be stably supported with high accuracy.

  That is, for example, when both ends of the Y-axis moving frame 22 are supported by linear motion guides, if the parallelism of the linear motion guides at both ends is not maintained with high accuracy, the Y-axis moving frame 22 is deformed such as torsion. However, by supporting one end with the Y-axis linear motion guide 44 and supporting the other end with the air bearing 70, the difference in parallelism between the two can be absorbed by the shaking of the Y-axis moving frame 22, and the Y-axis moving frame 22 deformation can be prevented.

In addition, since one end is supported by the Y-axis linear motion guide 44, the Y-axis moving frame 22 is
The linearity for moving on the axis is defined by the Y-axis slider 50 on the Y-axis guide rail 46 constituting the Y-axis linear motion guide 44. For this reason, it goes straight in the Y-axis direction on the basis of one guide rail (Y-axis guide rail 46), and does not swing left and right when moving in the Y-axis direction. Thereby, the displacement of a yawing direction can be suppressed. In general, levitation support using an air bearing is difficult to ensure straightness during movement, and displacement in the yawing direction is large. For this reason, if both ends of the Y-axis moving frame 22 are lifted and supported by the air bearing, the direction is slightly changed to the left and right with respect to the moving direction, and the displacement in the yawing direction is increased. On the other hand, the linear movement for moving the Y-axis moving frame 22 in the Y-axis direction by supporting one end with the Y-axis linear movement guide 44 as in the present embodiment is the linear movement of the Y-axis linear movement guide 44. Can be defined by sex. For this reason, the Y-axis moving frame 22 moves straight on the basis of the Y-axis linear motion guide 44. As a result, displacement in the yawing direction can be suppressed. Thereby, vibration in the yawing direction during acceleration / deceleration can be suppressed, and highly accurate measurement can be performed.

  Further, since the Y-axis moving frame 22 has a structure in which both ends are supported, deformation due to its own weight does not occur as in the case of cantilever support.

  Furthermore, in general, the levitation support by the air bearing has a drawback that the displacement in the yawing direction is large. However, in the measuring machine 10 of the present embodiment, one end is supported by the Y-axis linear motion guide 44. Can also be suppressed.

  In addition, since only one side is supported by the air bearing 70, the consumption of compressed air can be suppressed.

  Further, in the measuring instrument 10 of the present embodiment, since the drive belt 78 for driving the Y-axis moving frame 22 is disposed on the Y-axis guide rail 46, the hysteresis of the reciprocating movement can be eliminated. That is, since the driving point is arranged on the line that receives the sliding resistance, the hysteresis of the reciprocating movement can be eliminated. Thereby, the error due to yawing of the Y-axis moving frame 22 can be further reduced. That is, there is a large difference in sliding resistance between the one Y-axis linear guide 44 and the other air pad 72, and the Y-axis linear guide 44 is much larger. When the Y-axis moving frame 22 is driven, a driving means is provided on the Y-axis linear moving guide 44 side having a large sliding resistance, so that the Y-axis moving frame 22 can be moved on the basis of the linearity of the Y-axis linear moving guide 44. It is possible to go straight ahead. Thereby, when the Y-axis moving frame 22 moves in the Y direction, it is possible to prevent the Y-axis moving frame 22 from moving while changing its direction slightly from side to side. Thereby, the error due to yawing of the Y-axis moving frame 22 can be further reduced.

  Furthermore, the sliding resistance can be reduced by adopting a configuration in which it is supported by one Y-axis linear motion guide 44. Thereby, the heat generation of the Y-axis motor 80 can be suppressed, and deformation of the base and the like due to thermal stress can be suppressed.

  If the Y-axis moving frame 22 is supported so as to be swingable in the rolling direction (MR) as in the measuring instrument 10 of the present embodiment, an error may occur in the contact position of the probe due to the swinging. Since the error change due to the swing of the Y-axis moving frame 22 is reproducible, it can be easily corrected.

  As described above, when both ends of the Y-axis moving frame are supported by the linear motion guide, or when one end of the Y-axis moving frame is supported by the pair of linear motion guides, the Y-axis moving frame is deformed (twisted). , Deflection, etc.) may occur, but the deformation changes depending on the temperature or the like. For this reason, the reproducibility of the error change is poor, and it is difficult to accurately grasp the influence on the measurement value caused by the deformation of the Y-axis moving frame.

  On the other hand, in the measuring machine 10 of the present embodiment, the Y-axis moving frame 22 is not deformed, and only the swing of the Y-axis moving frame 22 appears as a measurement error. Since the measurement error due to the swing of the Y-axis moving frame 22 is reproducible, it can be corrected with high accuracy by applying a commonly-known correction technique.

  Error correction is performed, for example, by measuring a reference workpiece (a workpiece whose dimensions, shape, etc. are known), calculating a correction formula from the measurement result, and correcting the measurement result using the obtained correction formula. .

  Moreover, according to the measuring instrument 10 of this Embodiment, since the Y-axis movement frame 22 is formed in L shape, the weight of the Y-axis movement frame 22 can also be reduced in weight. Thereby, the moment of inertia at the time of acceleration / deceleration can be reduced, and the displacement (vibration) in the dynamic pitching direction can be reduced. Also, the visibility of the measurement area from the side can be improved.

  Further, according to the measuring instrument 10 of the present embodiment, the work placement surface 14 </ b> A of the surface plate 14 is used as the guide surface of the air pad 72. Thereby, it is not necessary to provide a separate guide surface, and the configuration can be simplified. In general, since the work placement surface of the surface plate is flattened with high accuracy, the Y-axis moving body can be guided with high accuracy.

  In addition, the work placement surface 14A of the surface plate 14 is used as a guide surface of the air pad 72, so that the following effects can be achieved independently. The reference plane in the Z direction of the workpiece is the workpiece placement surface 14A of the surface plate 14. The probe 120 is brought into contact with the workpiece placement surface 14A, and the height can be defined on the basis of the workpiece placement surface with the point of contact as 0 point. On the other hand, the reference surface of the Y-axis moving frame 22 including the probe 120 is also the workpiece placement surface 14A. The Y-axis moving frame 22 is configured so as to constantly move up and down based on the workpiece placement surface 14 </ b> A by the flying force of the air pad 72, and the Y-axis linear motion guide 44 side, which is one support point, is arranged on the Y-axis guide rail 46. It is set as the structure which rock | fluctuates (rotates) centering on this. For example, even when the parallelism between the Y-axis guide rail 46 and the work placement surface 14A of the surface plate 14 is not ensured, the work placement surface 14A is moved under a constant levitation force formed by the air pad 72. As a reference, the Y-axis moving frame 22 is lifted, adjusted by swinging (turning) at the Y-axis guide rail 46, and the Y-axis moving frame 22 follows without being bent and deformed. Therefore, since the workpiece and the probe 120 are based on the workpiece placement surface 14A, it is possible to measure accurately under the same reference surface.

  Also, since the measurement reference plane is defined as one plane for both the workpiece and the probe 120, control and management can be facilitated, and even if there is a minute aging of the apparatus, it can be configured sequentially. Highly accurate measurement can be ensured for a long time.

  Further, in the measuring instrument 10 of the present embodiment, since the Y-axis linear motion guide 44 is disposed above the tip of the probe 120, the entire Y-axis moving mechanism is less likely to collapse. Thereby, the pitching error can be greatly reduced.

  The Y-axis guide rail 46 constituting the Y-axis linear motion guide 44 serves as a fulcrum that supports the Y-axis moving frame 22. Strictly speaking, the fulcrum is two points, that is, the Y-axis guide rail 46 portion and the workpiece placement surface 14A portion of the surface plate 14 that supports the air pad 72, but the air pad 72 is not in contact with the surface plate 14. Therefore, the point that substantially supports the Y-axis moving frame 22 is a portion of the Y-axis guide rail 46. On the other hand, the position of the center of gravity in the movement in the Y-axis direction is most preferably near the tip of the probe 120 from the viewpoint of measurement error. However, strictly speaking, it is slightly above the tip of the probe 120. However, it is possible to position the position of the center of gravity below the fulcrum position of the Y-axis guide rail 46. Since the position of the center of gravity is lower than the fulcrum position that is slid by such a drive mechanism, the entire Y-axis moving mechanism can be prevented from falling down. And by making it the structure which is hard to fall down in this way, the effect that the error (error which shakes in the front-back direction when moving) in a pitching direction can be remarkably reduced can be produced. As described above, since the Y-axis linear motion guide 44 is disposed above the tip of the probe 120, the pitching error can be greatly reduced, and the measurement accuracy can be further improved.

  Further, when the Y-axis linear motion guide 44 is disposed above the tip of the probe 120, the following effects are obtained. When the Y-axis guide rail 46 is disposed above the tip of the probe 120, the workpiece measurement site is two fulcrums (part of the Y-axis guide rail 46) supporting the Y-axis moving frame 22 in the Z direction and the X direction. And the portion of the surface plate 14 facing the air pad 72). The presence of the workpiece measurement site at approximately the middle position between the two fulcrums in this way does not promote minute vibrations or minute displacements at the respective fulcrum portions, but cancels them or at least reduces them. It will be. In the case of a bridge-type measuring machine or a gantry-type measuring machine, the workpiece measurement site exists farther than the positions of the two fulcrums. Therefore, there is a problem that a slight vibration of the fulcrum part is promoted by the moment, resulting in a larger error. However, when the Y-axis linear motion guide 44 is disposed above the tip of the probe 120, there is no problem that vibration and displacement are promoted in this way.

  In order to bring the position of the center of gravity closer to the vicinity of the tip of the probe 120, it is preferable that the Y-axis slider 50 is attached in the vicinity of the same plane as the lower surface of the beam portion 22A of the Y-axis moving frame 22. Further, it is preferable that the tip of the probe 120 is moved vertically downward, and a control device for the probe 120 is mounted near the probe to lower the center of gravity.

<< Second Embodiment >>
FIG. 8 is a front view showing a second embodiment of the measuring instrument according to the present invention. FIG. 9 is a right side view of the measuring machine shown in FIG.

  As shown in the figure, the measuring instrument 10A of the present embodiment is different from the measuring instrument 10 of the first embodiment in that the Y-axis moving frame 22 is formed in a so-called portal shape (so-called bridge). Type). Therefore, here, only differences from the measuring instrument 10 of the first embodiment in terms of structure will be described, and the same or corresponding configurations as those of the measuring instrument 10 of the first embodiment are denoted by the same reference numerals. Therefore, the description is omitted.

  As shown in FIG. 8, the Y-axis moving frame 22 includes a horizontal beam portion 22A and a pair of support column portions 22B and 22C extending vertically downward from both ends of the horizontal beam portion 22A. As a whole, the gate shape is formed. That is, the Y-axis moving frame 22 of the measuring instrument 10 according to the first embodiment is formed in substantially the same shape as the shape in which the support portion 22C is further provided.

  Since the Y-axis moving frame 22 is formed in a portal shape in this way, the measuring machine 10A of the present embodiment is not provided with a Y-axis column.

  In the Y-axis moving frame 22, one supporting column portion 22 </ b> B is levitated and supported on the surface plate 14 by the air bearing 70, and the other supporting column portion 22 </ b> C is supported by the Y-axis guide mechanism 20 so as to be movable in the Y-axis direction.

  The Y-axis guide mechanism 20 includes a Y-axis table 42 and one Y-axis linear motion guide 44 that supports the Y-axis table 42 movably along the Y-axis.

  The Y-axis linear motion guide 44 includes a Y-axis guide rail 46 and a Y-axis slider 50 that is slidably supported on the Y-axis guide rail 46 via a plurality of balls (not shown). The Y-axis guide rail 46 is laid on the Y-axis base 18 along the Y-axis.

  The Y-axis base 18 is formed in a long shape and is attached to the surface plate 14 along the Y-axis.

  The Y-axis moving frame 22 is supported by a lower end portion of one column portion 22C fixed to a Y-axis table 42 so as to be movable in the Y-axis direction.

  As described above, also in the measuring instrument 10A of the present embodiment, the Y-axis moving frame 22 is supported by the single Y-axis linear motion guide 44 and the air bearing 70 so as to be movable in the Y-axis direction. As a result, the Y-axis moving frame 22 can move flexibly in the rolling direction (MR) and can be supported without causing deformation of the Y-axis moving frame 22.

  Further, in the measuring instrument 10A of the present embodiment, the Y-axis moving frame 22 is formed in a portal shape, so that the visibility from the side can be further improved.

  In this example, the Y-axis base 18 is installed on the surface plate 14, and the Y-axis linear motion guide 44 and the like are installed on the Y-axis base 18, but the Y-axis linear motion guide 44 and the like are fixed. It can also be set as the structure installed in the board 14. FIG.

<< Third Embodiment >>
FIG. 10 is a front view showing a third embodiment of the measuring instrument according to the present invention. FIG. 11 is a left side view of the measuring machine shown in FIG.

  As shown in the figure, the measuring instrument 10B of the present embodiment is different from the measuring instrument 10 of the first embodiment in that the Y-axis moving frame 22 is formed in a bar shape extending linearly ( So-called gantry type). Therefore, here, only differences from the measuring instrument 10 of the first embodiment in terms of structure will be described, and the same or corresponding configurations as those of the measuring instrument 10 of the first embodiment are denoted by the same reference numerals. Therefore, the description is omitted.

  The Y-axis moving frame 22 is formed in a prismatic bar shape. That is, the Y-axis moving frame 22 of the measuring instrument 10 according to the first embodiment is formed in substantially the same shape as when only the beam portion 22A is configured.

  Since the Y-axis moving frame 22 is formed in a linear bar shape in this way, a pair of Y-axis columns are provided on the surface plate 14 in the measuring instrument 10B of the present embodiment. That is, the first Y-axis column 16 and the second Y-axis column 17 are provided.

  The first Y-axis column 16 is formed in a V shape similarly to the Y-axis column 16 of the measuring instrument 10 of the first embodiment. And the 1st Y-axis base 18 is supported horizontally at the upper part.

  Similarly to the first Y-axis column 16, the second Y-axis column 17 is also formed in a V shape. A second Y-axis base 19 is supported horizontally on the Y-axis column 17.

  The second Y-axis base 19 is formed in a prismatic shape. The upper surface 19A of the second Y-axis base 19 constitutes a guide surface of the air bearing 70. For this reason, the upper surface 19A of the second Y-axis base 19 is formed smoothly. The second Y-axis base 19 is supported by the second Y-axis column 17 so that the upper surface 19A is horizontal (parallel to the XY plane).

  One end of the Y-axis moving frame 22 is guided by the Y-axis guide mechanism 20 and supported so as to be movable in the Y-axis direction, and the other end is supported on the guide surface (the upper surface 19A of the second Y-axis base 19) by the air bearing 70. The levitation is supported.

  The Y-axis guide mechanism 20 includes a Y-axis table 42 and one Y-axis linear motion guide 44 that supports the Y-axis table 42 movably along the Y-axis.

  The Y-axis linear motion guide 44 includes a Y-axis guide rail 46 and a Y-axis slider 50 that is slidably supported on the Y-axis guide rail 46 via a plurality of balls (not shown). The Y-axis guide rail 46 is laid on the first Y-axis base 18 along the Y-axis.

  One end of the Y-axis moving frame 22 is fixed to the Y-axis table 42 and supported so as to be movable in the Y-axis direction.

  The air bearing 70 includes an air pad 72 and supports the other end of the Y-axis moving frame 22 in a floating manner with the upper surface 19A of the second Y-axis base 19 as a guide surface.

  The air pad 72 is attached to the other end of the Y-axis moving frame 22 via a universal joint 74. The air pad 72 injects compressed air toward the upper surface 19A of the second Y-axis base 19 to form an air layer between the upper surface 19A of the second Y-axis base 19 and the Y-axis moving frame. The other end of 22 is levitated and supported with respect to the upper surface 19 </ b> A of the second Y-axis base 19.

  As described above, also in the measuring instrument 10A of the present embodiment, the Y-axis moving frame 22 is supported by the single Y-axis linear motion guide 44 and the air bearing 70 so as to be movable in the Y-axis direction. As a result, the Y-axis moving frame 22 can move flexibly in the rolling direction (MR) and can be supported without causing deformation of the Y-axis moving frame 22.

  In the measuring instrument 10B of the present embodiment, the Y-axis moving frame 22 can be reduced in weight because the Y-axis moving frame 22 has a bar shape. Thereby, the moment of inertia at the time of acceleration / deceleration can be reduced.

  Further, since the Y-axis moving frame 22 can support in the Y-axis direction close to the center of gravity, dynamic displacement in the pitching direction during acceleration / deceleration can be suppressed, and a stable and highly accurate guide can be achieved.

  On the other hand, in the measuring machine 10B of the present embodiment, since the Y-axis columns (the first Y-axis column 16 and the second Y-axis column 17) are erected on both sides of the surface plate 14, the side The visibility of the measurement area from the direction is reduced.

  Therefore, considering the visibility and the stability of movement, it is preferable that the Y-axis moving frame 22 has an L shape as a whole as in the first embodiment.

<< Other Embodiments >>
In the above embodiment, as a support mechanism for supporting one end of the Y-axis moving frame 22 along the Y-axis, the guide rail (Y-axis guide rail 46) and the guide rail are slidably supported via the rolling elements. A linear motion guide (Y-axis linear motion guide 44) comprising a slider (Y-axis slider 50) is employed, but a support mechanism for supporting one end of the Y-axis moving frame 22 along the Y-axis is It is not limited. Any structure that can support the Y-axis moving frame 22 so as to be swingable around the Y-axis when the other end is supported by levitation with an air bearing is acceptable. For this purpose, one guide rail and a slider that is slidably supported by the guide rail are provided, and the slider is supported so as to be swingable with respect to the guide rail in the rolling direction. Any acceptable structure may be used. In this case, it is preferable that the structure is strong against displacements other than the rolling direction, that is, displacements in the pitching direction and the yawing direction. Thereby, the displacement in the pitching direction and the yawing direction can be prevented, and the Y-axis moving frame 22 can be guided along the Y-axis with high accuracy.

  In the above embodiment, the Y-axis slider 50 is belt-driven and the Y-axis moving frame 22 is moved in the Y-axis direction. However, the means for driving the Y-axis moving frame 22 (Y-axis driving means). However, the present invention is not limited to this. Any configuration that can move the Y-axis moving frame 22 along the Y-axis while allowing the Y-axis moving frame 22 to swing with the support portion of the Y-axis slider 50 as a fulcrum is acceptable.

  The Y-axis drive means preferably has a configuration in which the Y-axis moving frame 22 is moved by driving the Y-axis slider 50. By adopting a configuration in which the Y-axis slider 50 is driven, the Y-axis moving frame 22 can be moved straight on the basis of the straightness of the Y-axis guide rail 46, and yawing of the Y-axis moving frame 22 can be prevented. it can. This effect is independent from the effect of swingably supporting the Y-axis moving frame 22 with the support portion of the Y-axis slider 50 as a fulcrum. As in the measuring instrument 10 of the above embodiment, in a measuring instrument having a measuring unit at the center, as a means for supporting the measuring unit, one end is supported by a slider that slides along a guide rail, and the other end is an air pad. Having a mechanism for supporting the flying and providing a drive system on the slider side has an effect of reducing yawing that occurs during movement. That is, in the above configuration, when the Y-axis moving frame 22 is driven while taking the balance of the sliding resistance and the balance of the sliding resistance into account, the Y-axis moving frame 22 is driven straight while reducing the moment of inertia that slightly changes the direction in the left-right direction. As a result, a unique effect of eliminating errors due to yawing is produced.

  DESCRIPTION OF SYMBOLS 10, 10A, 10B ... measuring machine, 12 ... mount, 12A ... fixing leg, 12a ... foot, 12B ... fall prevention leg, 12b ... foot, 14 ... surface plate, 14A ... upper surface (guide surface) 16 ... Y-axis column, first Y-axis column, 16A ... base of Y-axis column, 16B ... post column of Y-axis column, 17 ... second Y-axis column, 18 ... Y-axis base, first Y-axis Axis base, 19 ... second Y-axis base, 19 ... upper surface (guide surface) of second Y-axis base, 20 ... Y-axis guide mechanism, 22 ... Y-axis movement frame, 22A ... beam portion of Y-axis movement frame , 22B, 22C ... Y-axis moving frame support, 24 ... Y-axis drive unit, 26 ... X-axis guide mechanism 26, 28 ... X-axis movement frame, 30 ... X-axis drive unit, 32 ... Z-axis guide mechanism, 34 ... Z-axis moving frame, 36 ... Z-axis drive unit, 38 ... Measurement 42 ... Y-axis table, 44 ... Y-axis linear motion guide, 46 ... Y-axis guide rail, 46A ... Y-axis guide rail base, 46B ... Y-axis guide rail support, 46C ... Y-axis guide rail rail , 48 ... Ball, 50 ... Y-axis slider, 52 ... Ball rolling surface, 54 ... Slider body, 54A ... Main girder part of slider body, 54C ... Leg part of slider body, 56 ... End plate, 58 ... Load rolling Surface, 60 ... load passage, 62 ... ball return passage, 70 ... air bearing, 72 ... air pad, 74 ... universal joint, 76A, 76B ... pulley, 78 ... drive belt, 80 ... Y-axis motor, 82A, 82B ... bracket, 84 ... Insertion hole, 86 ... X-axis table, 88 ... X-axis linear motion guide, 90 ... X-axis guide rail, 92 ... X-axis slider, 94 ... Screw rod, 96 ... Nut member, 98 ... X Motor, 100 ... Bracket, 102 ... Z axis table, 104 ... Z axis linear guide, 106 ... Z axis guide rail, 108 ... Z axis slider, 110 ... Screw rod, 112 ... Nut member, 114 ... Z axis motor, 116 ... Bracket, 118 ... Measurement body, 120 ... Probe

Claims (3)

In the CMM that measures the workpiece placed on the workpiece placement surface of the surface plate with a probe,
A Y-axis moving body comprising the probe;
A Y-axis linear motion guide that includes a linear guide rail disposed at a position higher than the workpiece, and supports one end of the Y-axis moving body along the guide rail so as to be movable in the Y-axis direction;
Y-axis drive means provided on the Y-axis linear motion guide side for moving the Y-axis moving body;
An air bearing that levitates and supports the other end of the Y-axis moving body using the workpiece placement surface as a guide surface;
CMM equipped with The Y-axis linear motion guide is rotatably supported around the guide rail.
The three-dimensional measuring machine according to claim 1. A scale for measuring the amount of movement of the Y-axis moving body is provided on the Y-axis linear motion guide side,
The three-dimensional measuring machine according to claim 1 or 2.

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