JP7096972B2 - CMM - Google Patents

Description

The present invention relates to a coordinate measuring machine, and particularly measures the shape, dimensions, etc. of a work (measurement object) using a probe provided so as to be movable in each of the X-axis, Y-axis, and Z-axis directions orthogonal to each other. Regarding 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 a work (measurement object), and the coordinate values thereof. The shape, dimensions, etc. of the work are measured from the set of. Therefore, the probe is provided so as to be movable in each of the three axes (X-axis, Y-axis, and Z-axis) orthogonal to each other.

The mechanism for moving the probe is generally provided in a Y-axis moving body that moves along the Y-axis, an X-axis moving body that is provided in the Y-axis moving body and moves along the X-axis, and an X-axis moving body. It consists of a Z-axis moving body that moves along the Z-axis, and 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 be able to configure this with high accuracy. In particular, since the X-axis moving body and the Z-axis moving body are mounted on the Y-axis moving body, it is required to move with high accuracy without deformation. For this reason, various methods have been proposed for the mechanism for moving the probe along the Y axis in the coordinate measuring machine (for example, Patent Documents 1, 2, etc.).

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 gate-shaped shape in which the Y-axis moving body 1002 includes a pair of legs 1002A and 1002B. In the Y-axis moving body 1002, both legs 1002A and 1002B are supported by air bearings and slidably supported in the Y-axis direction. That is, one leg 1002A is slidably supported by one guide rail 1006 arranged on the base 1004 via the air pad 1008A, and the other leg 1002B is slidably supported on the horizontal plane of the base 1004 via the air pad 1008B. It is slidably supported (for example, Patent Documents 3, 4, etc.).

Other bridge-type coordinate measuring machines include a method in which both legs are slidably supported by a mechanical linear motion guide bearing (linear motion guide) (for example, Patent Document 5 and the like), and one leg. A method is known in which a portion is slidably supported by a pair of mechanical linear motion guide bearings and the other leg portion is slidably supported by an air bearing (for example, Patent Document 6 and the like).

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 arranged on the base 1104, and is slidably slidable on each column 1106A and 1106B via linear motion guides 1108A and 1108B. It is supported (for example, Patent Document 7 and the like).

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 and supported by one column 1206 disposed on the base 1204 and slidably supported on the column 1206 via a pair of linear motion guides 1208A and 1208B (eg, patent). Document 8 etc.).

Japanese Unexamined Patent Publication No. 5-248840 Special Table 2000-510241 Jitsufuku No. 7-3283 Gazette Japanese Unexamined Patent Publication No. 5-99651 Jitsufuku 7-25605 Gazette Japanese Unexamined Patent Publication No. 2006-287098 Japanese Unexamined Patent Publication No. 2010-122118 Japanese Unexamined Patent Publication No. 2010-181157

A bridge-type CMM that floats and supports both legs with air bearings has the advantage of being able to guide the Y-axis moving body with less sliding resistance without causing deformation of the Y-axis moving body. ..

However, the bridge type three-dimensional measuring machine in which both legs are floated and supported by air bearings has a problem that the dynamic displacement in the pitching direction and the yawing direction during acceleration / deceleration is large. The dynamic displacement in the pitching direction and the yawing direction during acceleration / deceleration appears as vibration and converges over time, but if the measurement is performed before the convergence, there is a problem that a measurement error occurs. In particular, in a bridge-type coordinate measuring machine, the center of gravity of the moving body is located above the support point on the drive side, and the distance between them is also large, so that the structure is easy to fall down. Therefore, there is a drawback that the moment of inertia in the pitching direction, which is proportional to the ease of tilting during acceleration / deceleration, becomes large, vibration is generated in the pitching direction, and a pitching error is likely to occur.

Further, in the bridge type three-dimensional measuring machine in which both legs are levitated and supported by air bearings, there is no sliding resistance on both legs. In this case, if the Y-axis moving body is propelled at the intermediate position of both legs, the Y-axis moving body moves in a well-balanced manner, but if only one leg is driven, the driven leg moves with a delay. And the left and right propulsion balance becomes unbalanced. Therefore, there is a drawback that the dynamic error in the yawing direction becomes large.

Further, when both legs are floated and supported by air bearings, since there is no sliding resistance at all, it takes a long time for the statically determinate time until the minute vibration after driving settles down.

Furthermore, in the bridge type, the position of the center of gravity is relatively higher than the position of the fulcrum, so the pitching error due to the inertial force when starting to move becomes large, and it takes an extremely long time for the pitching to stop the shaking in the front-rear direction. There is also a drawback.

It also has the disadvantages of high consumption of compressed air and high running costs.

On the other hand, the bridge type three-dimensional measuring machine in which both legs are supported by a linear motion guide has a drawback that the sliding resistance generated in both legs increases. If only one leg is driven with high sliding resistance in both cases, the driven leg will move with a delay, and the left and right propulsion will not be balanced, resulting in a large dynamic error in the yawing direction. There is a drawback. As a result, there is a drawback that the hysteresis of the movement becomes large on the left and right of the linear motion guide, the yawing becomes large, and a measurement error is likely to occur.

Further, since it is supported by two linear motion guides, there is a drawback that the drive unit tends to generate heat (heat generation of the drive unit generates thermal stress in the main body of the device, causing deformation of the guide unit and the like).

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 due to changes over time, the linear motion guides 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. In general, the error in the contact position of the probe due to the deflection of the Y-axis moving body can be corrected to some extent by the correction formula obtained from the measurement result of the reference work, but the effect of the change in the amount of deflection is also corrected accurately. Has the problem of being difficult.

Further, even in a coordinate measuring machine in which 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 is a drawback that the sliding resistance is large and the drive unit tends to generate heat.

Further, the support portion of the pair of linear motion guides has 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 platen surface (work mounting surface of the platen). When and change in the Y-axis direction, the support part by the linear motion guide is flexible in response to the resistance force received from the air bearing by the other leg in the process of moving the Y-axis moving body in the Y-axis direction. The configuration cannot be rotated. As a result, there is a drawback that the Y-axis moving body is deformed in a warped shape in the X-axis direction. Generally, 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 coordinate measuring machine is supported by two linear motion guides, so that it has a drawback that the sliding resistance is large and the yawing error is large. Further, if the parallelism of the two linear motion guides is not maintained with high accuracy, there are drawbacks that the Y-axis moving body is deformed during movement and that the two linear motion guides do not move smoothly during movement.

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

Further, the gantry type coordinate measuring machine has a drawback that the visibility of the measuring area is poor because a pair of columns are installed on the base.

Further, the cantilever type coordinate measuring machine has a drawback that the rigidity is low and the bending due to its own weight is likely to occur because the Y-axis moving body is cantilevered and supported.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a coordinate measuring machine capable of high-precision measurement based on a surface plate with small pitching error and yawing error.

The means for solving the problem are as follows.

The first aspect is the Y-axis guide means, the Y-axis moving body guided by the Y-axis guide means and moving in the Y-axis direction, the X-axis guide means provided in the Y-axis moving body, and the X-axis guide means. An X-axis moving body that is guided and moves in the X-axis direction, a Z-axis guiding means provided in the X-axis moving body, a Z-axis moving body that is guided by the Z-axis guiding means and moves in the Z-axis direction, and a Z-axis. In a measuring machine provided with a measuring unit provided on a moving body and measuring a workpiece by moving the measuring unit in the X-axis, Y-axis, and Z-axis directions, the Y-axis guide means is one parallel to the Y-axis. A slider that is slidably provided on the guide rail via a plurality of rolling elements, and one end of the Y-axis moving body in the X-axis direction is connected to guide the Y-axis moving body in the Y-axis direction, and Y. It is attached to the other end of the Y-axis moving body in the X-axis direction with the guide surface parallel to the axis and the X-axis, and forms an air film between the guide surface and the other end of the Y-axis moving body in the X-axis direction. It is a measuring machine provided with an air pad that slidably supports the guide surface in a non-contact manner.

According to this aspect, one end of the Y-axis moving body is slidably supported on one guide rail via a slider, and the other end is floated and supported on a guide surface via an air pad. As a result, the Y-axis moving body can be swayed (rotated) around an axis parallel to the Y-axis (swing (rotate) in the rolling direction) around the support portion of the slider by the guide rail. It is supported.). That is, 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 with reference to the measurement base position on the guide surface with a constant drag, so that measurement in the Z direction can be performed with reference to the measurement base. Further, this can prevent the Y-axis moving body from bending and deforming. That is, when the two guide rails are slidably supported by the sliders, if the parallelism of the two guide rails is not maintained with high accuracy, the Y-axis moving body is deformed such as twisting. By supporting one end with one guide rail and floatingly supporting the other end with an air pad, the difference in parallelism between the two can be seen as the shaking of the Y-axis moving body (the Y-axis starting from the support part of the slider by the guide rail). It can be absorbed by the rotational motion around the parallel axis (rotational motion in the rolling direction), and the 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. This makes it possible to prevent measurement errors caused by deformation of the Y-axis moving body.

Further, since one end is supported by one guide rail via 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. Therefore, the rail travels straight in the Y-axis direction with respect to one guide rail, and does not swing left or right when moving in the Y-axis direction. This makes it possible to suppress the displacement in the yawing direction. In general, the levitation support by the air bearing makes it difficult to secure the 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 floated and supported by air bearings, the direction is slightly changed to the left and right with respect to the moving direction, and the displacement in the yawing direction becomes large. On the other hand, as in this embodiment, the straightness for moving the Y-axis moving body in the Y-axis direction by supporting one end with the guide rail is defined by the straightness of the guide rail with reference to the guide rail at one end. Can be made to. Therefore, the Y-axis moving body moves straight ahead with respect to one of the guide rails. As a result, the displacement in the yawing direction can be suppressed. As a result, vibration in the yawing direction during acceleration / deceleration can be suppressed, and highly accurate measurement can be performed.

Further, by adopting a configuration in which only one side is floated and supported by an air pad, the consumption of compressed air can be suppressed. As a result, the running cost can be suppressed. Further, the sliding resistance can be reduced by supporting the structure with one guide rail. As a result, 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 the aspect in which the measuring machine of the first aspect further includes a Y-axis driving means for driving a slider to move the Y-axis moving body in the Y-axis direction.

According to this aspect, the Y-axis driving means for driving the Y-axis moving body is arranged not on the air pad side but on the guide rail side. This makes it possible to further reduce the error due to yawing of the Y-axis moving body. That is, the magnitude of the sliding resistance differs between one slider portion and the other air pad portion, and the slider portion is significantly larger. When driving the Y-axis moving body, by providing the driving means on the slider side where the sliding resistance is large, the Y-axis moving body can be made to go straight based on the straightness of the guide rail. As a result, when the Y-axis moving body moves in the Y direction, it does not move while slightly alternating left and right, and moves along the straightness of the guide rail. As a result, it is possible to further reduce the error due to yawing of the Y-axis moving body.

The effect of this aspect is independent of the effect of the first aspect, that is, the effect of swingably supporting the Y-axis moving body (the effect of preventing the Y-axis moving body from being deformed). be. In this embodiment, in a measuring machine having a measuring unit in the center, as a means for supporting the measuring unit, one end is supported by a slider sliding along a guide rail, and the other end is floated and supported by an air pad. By providing a drive system on the slider side, it has the effect of reducing yawing (movement that moves while turning slightly to the left and right alternately) that occurs during movement. That is, in this embodiment, when the Y-axis moving body is driven while taking into consideration the balance of the sliding resistance and the balance of the sliding resistance, the Y-axis moving body is driven straight while reducing the moment of inertia that slightly changes the direction in the left-right direction. As a result, a unique action effect of eliminating the error due to yawing is produced.

As described above, when both ends of the Y-axis moving body are levitated and supported by air pads, the standard straightness cannot be secured and there is no sliding resistance, so if only one side is driven, the orientation is easy. There is a drawback that the yawing becomes large because it changes. Further, when both ends are supported by sliders, if only one side is driven in the same manner, there is a drawback that the yawing error becomes larger. Further, if they are not parallel to each other, there is a drawback that the movement itself is not smooth.

The third aspect is the aspect in which the guide rail is arranged above the measuring unit in the measuring machine of the first or second aspect.

The guide rail serves as a fulcrum that supports the Y-axis moving body. Strictly speaking, there are two fulcrums, the guide rail part and the guide surface part that supports the air pad, but 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, it is most desirable from the viewpoint of measurement error that the position of the center of gravity in the Y-axis movement is the measurement unit (near the tip of the probe when measuring with the probe). However, strictly speaking, it is slightly above the measuring unit. However, it is possible to position the position of the center of gravity below the position of the fulcrum of the guide rail. Since the position of the center of gravity is lower than the position of the fulcrum that slides by such a drive mechanism, the entire Y-axis movement mechanism can be made to have a structure that does not easily collapse. And, by making the structure hard to fall down like this, it is possible to achieve the effect that the error in the pitching direction (the error of swinging in the front-back direction when moving) can be remarkably reduced. By setting the position of the measuring unit (the position of the probe when measuring with the probe) lower than the position of the guide rail as the fulcrum in this way, the pitching error can be greatly reduced.

A fourth aspect is the measuring machine according to any one of the first to third aspects, further comprising a surface plate having a work mounting surface parallel to the X-axis and the Y-axis, and the work mounting surface is a guide surface of an air pad. It is an aspect that also serves as.

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

Further, by using the work mounting surface of the surface plate as the guide surface of the air pad, the following effects can be obtained. The reference plane in the Z direction of the work is the surface of the surface plate (upper surface), that is, the work mounting surface (surface plate surface) as a reference. When measuring with a probe, the height can be defined based on the work mounting surface by abutting the probe on the work mounting surface and setting the abutted point as 0 point. On the other hand, the reference surface of the Y-axis moving body including the probe is also the work mounting surface. The Y-axis moving body is configured to constantly move up and down with respect to the work mounting surface due to the levitation force of the air pad, and the guide rail side, which is one of the support points, swings (turns) 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 work mounting surface under the constant levitation force formed by the air pad, and the part of the guide rail. It is adjusted by swinging (rotating) with, and follows the Y-axis moving body without bending and deforming. Therefore, since the work and the probe are based on the work mounting surface, the measurement can be performed accurately under the same reference surface.

In addition, since the reference surface for measurement is defined as one surface for both the workpiece and the probe, control and management can be facilitated, and even if there is a slight secular change in the device, it can be configured sequentially. Highly accurate measurement can be ensured for a long period of time.

Further, when the guide rail is arranged above the measuring portion, the following effects are obtained. When the guide rail is arranged above the measurement unit, the measurement site of the work 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. It will be located in the position. The existence of the measurement site of the work at an approximately intermediate position between the two fulcrums in this way does not mean that minute vibrations and minute displacements at each fulcrum are promoted, but are canceled out or at least reduced. Will be done. In the case of a bridge-type measuring machine or a gantry-type measuring machine, the measurement sites of the work are located farther apart than the positions of the two fulcrums. Therefore, there is a problem that a small amount of vibration of the fulcrum portion 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.

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

According to this aspect, the Y-axis moving body has an L-shape including an X-axis base portion and a leg portion. The Y-axis moving body is supported so as to be movable in the Y-axis direction by connecting a slider to the tip end portion of the X-axis base portion and attaching an air pad to the lower end portion of the leg portion. The L-shape makes it possible to reduce the weight of the moving portion as compared with the bridge type. As a result, the moment of inertia during acceleration / deceleration can be reduced, and the dynamic displacement (vibration) in the pitching direction can be reduced. In addition, the visibility of the measurement area can be improved.

A sixth aspect is the aspect in which the measuring machine of the fifth aspect further includes a Y-axis base provided with a guide rail and a V-shaped Y-axis column provided on a surface plate and supporting the Y-axis base. Is.

According to this aspect, the Y-axis base on which the guide rails are arranged is installed on the surface plate via the V-shaped Y-axis column. This makes it possible to improve the visibility of the measurement area. In addition, the surface plate is generally 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. As a result, the influence of bimetal can be minimized.

A seventh aspect is that in the measuring machine according to any one of the first to third aspects, the Y-axis moving body is parallel to the 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 legs, a slider is connected to the lower end of one leg, an air pad is attached to the lower end of the other leg, and an X-axis guide means is attached to the X-axis base. It is a mode to be provided.

According to this aspect, the Y-axis moving body has a phylum shape. This makes it possible to improve the visibility of the measurement area.

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

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

A ninth aspect is the first Y-axis base provided with a platen having a work mounting surface parallel to the X-axis and the Y-axis and a guide rail in the measuring machine according to any one of the first to third aspects. A first Y-axis column provided on the platen to support the first Y-axis base, a second Y-axis base having a guide surface, and a second Y-axis base provided on the platen. Further comprising a second Y-axis column to support, the Y-axis moving body is an embodiment having 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 to the minimum necessary size, that is, the minimum size that can secure the movement of the X-axis moving body. As a result, the weight of the moving portion can be reduced, and the moment of inertia during acceleration / deceleration can be reduced.

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

According to this aspect, the air pad is attached to the Y-axis moving body via the free joint. As a result, even if the guide surface has a swell, the air pad can swing along the swell, and the Y-axis moving body can be prevented from receiving a twisting moment.

The eleventh aspect is a movement guide mechanism of a measuring machine that guides a moving body on which a measuring unit is mounted along a horizontal axis, one guide rail arranged in parallel with the axis, and a plurality of guide rails. A slider, a horizontal guide surface, and a guide surface attached to the other end of the moving body, which are slidably provided via the rolling element of the moving body and are connected to one end of the moving body to guide the moving body along an axis. It is a movement guide mechanism of a measuring instrument including an air pad that forms an air film between the two and slidably supports the other end of the moving 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 a slider, and the other end is floated and supported on a guide surface via an air pad. As a result, the moving body is swingably supported (supported swingably in the rolling direction) around an axis parallel to the Y axis, starting from the support portion of the slider by the guide rail. By enabling flexible swinging with respect to the moving body in this way, deformation of the moving body can be prevented. Moreover, since both ends are supported, deformation due to its own weight can be prevented. This makes it possible to prevent measurement errors caused by deformation of the moving body. Further, since one end is supported by one guide rail via the slider, the displacement in the yawing direction can be suppressed. As a result, vibration in the yawing direction during acceleration / deceleration can be suppressed, and highly accurate measurement can be performed. Further, by adopting a configuration in which only one side is floated and supported by an air pad, the consumption of compressed air can be suppressed. As a result, the running cost can be suppressed. Further, the sliding resistance can be reduced by supporting the structure with one guide rail. As a result, heat generation of the drive unit (motor) can be suppressed, and deformation of the base due to thermal stress can be suppressed.

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

According to this aspect, the moving body has an L-shape. As a result, the weight of the moving portion can be reduced as compared with the bridge type, and the moment of inertia during acceleration / deceleration can be reduced. In addition, the visibility of the measurement area can be improved.

A thirteenth aspect is a movement guide mechanism of a measuring machine that guides a moving body on which a measuring unit is mounted along a horizontal axis, supporting one end of the moving body and linearly guiding the moving body along the axis. A movement guide mechanism for a measuring instrument comprising one mechanical linear motion guide bearing and at least one air bearing that floats and supports the other end of the moving body.

According to this aspect, one end of the moving body is supported by a linear motion guide bearing, and the other end is supported by an air bearing. As a result, the moving body can be swingably supported (supported swingably in the rolling direction) at the portion of the linear motion guide bearing, and deformation of the moving body can be prevented. Moreover, since both ends are supported, deformation due to its own weight can be prevented. This makes it possible to prevent measurement errors caused by deformation of the moving body. Further, since one end is supported by the linear motion guide bearing, the displacement in the yawing direction can be suppressed. This makes it possible to suppress vibration in the yawing direction during acceleration / deceleration. Further, by adopting a configuration in which only one side is floated and supported by an air bearing, the consumption of compressed air can be suppressed. As a result, the running cost can be suppressed. Further, the sliding resistance can be reduced by supporting the bearing with one linear motion guide bearing. As a result, heat generation of the drive unit (motor) can be suppressed, and deformation of the base due to thermal stress can be suppressed.

The fourteenth aspect is in the movement guide mechanism of the measuring machine of the thirteenth aspect, in which the moving body has an L-shape composed of a leg portion and a base portion, and the tip portion of the base portion is supported by a linear motion guide bearing. The lower end of the leg is supported by an air bearing, and the measuring unit is mounted on the base.

According to this aspect, the moving body has an L-shape. As a result, the weight of the moving portion can be reduced as compared with the bridge type, and the moment of inertia during acceleration / deceleration can be reduced. In addition, the visibility of the measurement area can be improved.

According to the present invention, running cost can be suppressed and highly accurate measurement can be performed. In addition, a measuring machine with high visibility can be configured.

Front view showing the first embodiment of the measuring machine according to the present invention. Left side view of the measuring instrument shown in FIG. Right side view of the measuring instrument shown in FIG. Plan view of the measuring machine shown in FIG. Perspective view showing the configuration of the linear motion guide 6-6 sectional view of FIG. Explanatory drawing of operation of measuring machine which concerns on this invention Front view showing the second embodiment of the measuring machine which concerns on this invention. Right side view of the measuring instrument shown in FIG. Front view showing a third embodiment of the measuring machine according to the present invention. Left side view of the measuring instrument shown in FIG. Front view showing the schematic configuration of a conventional measuring machine

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

<< First Embodiment >>
<Device configuration>
1 is a front view showing a first embodiment of the measuring machine 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 machine shown in FIG. 1, respectively. Is.

The measuring machine 10 is a so-called three-dimensional measuring machine, and measures the shape, dimensions, etc. of the work by using a probe provided so as to be movable in the directions of the X-axis, the Y-axis, and the Z-axis orthogonal to each other. ..

In this embodiment, the X-axis and the Y-axis form a horizontal axis, and the Z-axis forms a vertical axis. Therefore, the plane formed by the X-axis and the Y-axis constitutes a horizontal plane, and the plane formed by the X-axis and the Z-axis and the plane formed by the Y-axis and the Z-axis form a vertical plane.

The measuring machine 10 mainly includes a pedestal (base) 12, a platen 14 provided on the pedestal 12, a Y-axis column 16 provided on the platen 14, and a Y-axis base 18 supported by the Y-axis column 16. A Y-axis guide mechanism 20 provided on the Y-axis base 18, a Y-axis moving frame (Y-axis moving body) 22 guided by the Y-axis guide mechanism 20 and moving along the Y-axis, and a Y-axis moving frame 22. A Y-axis drive unit (Y-axis drive means) 24 that moves the vehicle along the Y-axis, an X-axis guide mechanism 26 provided in the Y-axis movement frame 22, and an X-axis guide mechanism 26 that guides the vehicle along the X-axis. A moving X-axis moving frame (X-axis moving body) 28, an X-axis driving unit (X-axis driving means) 30 for moving the X-axis moving frame 28 along the X-axis, and a Z provided in the X-axis moving frame 28. The axis guide mechanism 32, the Z-axis moving frame (Z-axis moving body) 34 guided by the Z-axis guide mechanism 32 and moving along the Z-axis, and the Z-axis moving the Z-axis moving frame 34 along the Z-axis. It is configured to include a drive unit 36 and a measuring unit 38 provided in the Z-axis moving frame 34.

The gantry 12 horizontally supports the surface plate 14. The gantry 12 includes three fixing legs 12A and two fall prevention legs 12B. The three fixing legs 12A are arranged at each apex position of the triangle, and the two fixing legs 12A are arranged at the front and rear corners on the right side of the surface plate 14. Further, the remaining one fixing leg portion 12A is arranged in the central portion of the left side of the surface plate 14. The two fall prevention legs 12B are arranged at the front and rear corners on the left side of the surface plate 14.

A height-adjustable foot portion 12a is provided at the tip of each fixing leg portion 12A. Similarly, the tip of each fall prevention leg 12B is provided with a height-adjustable foot 12b.

The surface plate 14 is a flat surface plate whose surface is correctly and smoothly finished. The work to be measured is placed on the surface plate 14. In the measuring machine 10 of the present embodiment, the surface plate 14 is formed in a rectangular shape. The X-axis and Y-axis are set parallel to the upper surface (work mounting surface (surface plate surface)) 14A of the surface plate 14, and the Z-axis is set perpendicular to the upper surface (work mounting surface 14A) of the surface plate 14. Will be done. Further, the X-axis is set parallel to the front and rear 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 position at a predetermined height from the surface plate 14. The Y-axis column 16 includes a base portion 16A and two strut 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 strut portions 16B are arranged so as to extend outward from the base portion 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, for example, cast iron. When the Y-axis column 16 is made of cast iron, the influence of bimetal due to a temperature change between the Y-axis column 16 and the surface plate 14 made of stone becomes a problem. 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. As a result, the influence of bimetal can be minimized. Further, by forming the Y-axis column 16 in a V shape, lateral visibility (visibility seen 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 arranged at a predetermined height from the surface plate 14. The Y-axis base 18 is arranged along the Y-axis.

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

The Y-axis guide mechanism 20 movably supports the Y-axis moving frame (Y-axis moving body) 22 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 movably supports the Y-axis table 42 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 LM guide (trademark)).

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

As shown in the figure, the Y-axis linear motion guide 44 is slidably supported on the Y-axis guide rail 46 via one Y-axis guide rail 46 extending linearly and a plurality of balls (rolling bodies) 48. It is configured to include a Y-axis slider 50 to be formed.

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 portion 46A is an installation portion on 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 the support portion 46B. The support portion 46B is thinner than the base portion 46A and the rail portion 46C, and 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. The Y-axis linear motion guide 44 of the present embodiment is provided with two ball rolling surfaces 52 on each side of the rail portion 46C, for a total of four balls. Each ball rolling surface 52 is formed along the axis of the Y-axis guide rail 46, and is formed so as to be inclined at an angle of 45 ° with respect to the bottom surface of the Y-axis guide rail 46 (the bottom surface of the base 46A).

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 of the ball 48, which is a rolling element. 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 of the slider main body 54 in the axial direction (sliding direction).

The slider main body 54 is configured to include a main girder 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 girder portion 54A is formed in the shape of a rectangular flat plate, and the upper surface portion thereof functions as a mounting surface for the Y-axis table 42.

The pair of leg portions 54B are arranged on both the left and right sides of the main girder portion 54A. Inside each leg portion 54B, a load rolling surface 58 on which the ball 48 rolls is provided. 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, it is arranged 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 two ball rolling surfaces 52 on each side of the rail portion 46C of the Y-axis guide rail 46, for a total of four rails. Therefore, the Y-axis slider 50 is also provided with two load rolling surfaces 58 inside each leg 54B, for a total of four loads.

As described above, the load rolling surface 58 of the slider main body 54 is arranged so as to face the ball rolling surface 52 on the guide rail side when the Y-axis slider 50 is attached to the Y-axis guide rail 46. .. As a result, the load passage 60 of 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 (cross-sectional shape in the direction orthogonal to the axial direction) is formed in a circular arc shape having a radius of curvature slightly larger than the radius of curvature of the spherical surface of the ball 48. However, this shape can be redesigned as appropriate. The ball rolling surface 52 provided on the Y-axis guide rail 46 is also formed in a circular arc shape.

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

The end plate 56 is formed corresponding to the shape of the slider main body 54, and the cross-sectional shape is formed into a substantially U-shape. The end plate 56 is provided with a turning path (not shown) corresponding to each ball return passage 62 of the slider main body 54 (two turning paths on the left and right, a total of four turning paths on one end plate 56). Be prepared.). The direction change path is formed in a U-shape, and the end plate 56 is attached to the slider main body 54 to communicate the ball return passage 62 and the load passage 60 of the slider main body 54. This constitutes an infinite circulation path for the ball 48.

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. It rolls in the load passage 60 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. Then, when it rolls out from the end of the load passage 60, it is released from the load and enters the turning path (not shown) in a no-load state. The ball 48 that has entered the turning path is guided by the turning path, changes its traveling direction by 180 °, and enters the ball return passage 62. After traveling in the ball return passage 62 in a no-load state, the ball 48 enters the turning path again, changes its traveling direction by 180 °, and enters the load passage 60. Then, the load passage 60 is rotated while the load acting between the Y-axis guide rail 46 and the Y-axis slider 50 is applied again. In this way, the ball 48 circulates in the infinite circulation path while alternately repeating the loaded state and the unloaded 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, the ball is used as the rolling element, but a roller or the like can also 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 composed of four rows, but the number of rows of the infinite circulation path is not limited to this. do not have. For example, the infinite circulation path may be a two-row row.

In the Y-axis linear motion 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 movably supported along the Y-axis.

Further, 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 the shape of a rectangular flat plate. 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 movement 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 strut portion 22B, and is arranged vertically along the X axis (arranged along the XZ plane). Will be.).

The beam portion 22A is formed in a substantially prismatic shape and is arranged along the X axis. The strut portion 22B is formed in a substantially prismatic shape and is arranged along the Z axis. The strut 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.

In the Y-axis moving frame 22, the tip of the beam portion 22A is fixed to the Y-axis table 42 and is slidably supported in the Y-axis direction. Further, in the Y-axis moving frame 22, the lower end of the support column portion 22B is floated and supported on the surface plate 14 by the air bearing 70.

The air bearing 70 includes an air pad 72, and floats and supports the support column portion 22B of the Y-axis moving frame 22 with the upper surface (work mounting surface) 14A 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 support column portion 22B. The air pad 72 injects compressed air toward the upper surface of the surface plate 14 (work mounting surface 14A) to form an air layer between the air pad 72 and the upper surface of the surface plate 14, and the support column 22B is formed on the surface plate 14. It floats and supports the upper surface of the surface plate.

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

As described above, one end (the tip of the beam portion 22A) of the Y-axis moving frame 22 is slidably supported 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 movably supported along the Y axis. By supporting the Y-axis moving frame 22 with such a structure, it is possible to prevent the Y-axis moving frame 22 from being deformed (twisted, bent, etc.) and move the Y-axis moving frame 22 with high accuracy. 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. Therefore, it is necessary to secure the length of the beam portion 22A by at least the moving stroke of the X-axis moving frame 28. Further, when both ends of the beam portion 22A are supported by a linear motion guide (mechanical linear motion guide bearing) and an air bearing, it is necessary to secure an installation interval between the two by the moving stroke of the X-axis moving frame 28. .. When the linear motion guide and the air bearing are installed apart from each other in this way, if the parallelism between the two is not maintained with high accuracy, the moment in the rolling direction (moment around the Y axis) is applied to the Y-axis moving frame 22. Occur.

Now, consider a case where both ends of the Y-axis moving frame 22 are supported by a linear motion guide (mechanical linear motion guide bearing). In this case, the moment generated in the Y-axis moving frame 22 acts directly 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 an 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, a linear motion guide (mechanical linear motion guide bearing) is strong against load moments in the pitching direction (MP direction in FIG. 5) and yawing direction (MY direction in FIG. 5) due to its structure, but is strong in the rolling direction (FIG. 5). It has the characteristic of being weak against the load moment (in the MR direction of 5). 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 with respect to the rolling direction (MR) as shown in FIG. Exercise 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.

Further, according to this structure, since both ends of the Y-axis moving frame 22 are supported, it is possible to prevent deformation due to its own weight as in the case of cantilever support.

Further, in general, levitation support by an 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 of being strong against load moments in the pitching direction and the yawing direction (because it is a mechanical linear motion guide bearing under pressure, the yawing rigidity is high. 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 by an air bearing.

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

In this way, by making good use of the characteristics of the air bearing and the linear motion guide, the Y-axis moving frame 22 can be movably supported 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 for rotationally driving one of the pulleys 76A.

The pair of pulleys 76A and 76B are installed on the Y-axis base 18 via the 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 arranged along the Y axis by being wound around a pair of pulleys 76A and 76B.

Here, the drive belt 78 is arranged on the same straight line as the Y-axis guide rail 46 of the Y-axis linear motion guide 44. That is, it is arranged so as to be overlapped with the Y-axis guide rail 46. By arranging the drive belt 78 in this way, 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 order to arrange the drive belt 78 in this way, the pair of pulleys 76A and 76B are arranged in front of and behind the Y-axis linear motion guide 44. Further, the Y-axis moving frame 22 is provided with an insertion hole 84 for passing the drive belt 78.

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

In the Y-axis drive unit 24 configured as described above, the drive belt 78 travels along the Y-axis direction by driving the Y-axis motor 80. The drive belt 78 is connected to the Y-axis table 42. As a result, 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 movement frame 22 moves along the Y-axis.

The X-axis guide mechanism 26 movably supports the X-axis moving frame 28 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 constituting the Y-axis guide mechanism 20. That is, it includes an X-axis guide rail 90 and an X-axis slider 92 slidably supported by the X-axis guide rail 90 via a plurality of balls (not shown). The X-axis guide rail 90 is laid on the beam portion 22A of the Y-axis moving frame 22 and is arranged along the X-axis.

The X-axis table 86 is formed in the shape of a rectangular flat plate. 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 in parallel with 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 a pair of X-axis linear motion guides 88, but since the installation interval of the pair of X-axis linear motion guides 88 is short, deformation of the X-axis moving frame 28 is a problem. Will never be.

The X-axis drive unit 30 moves the X-axis moving frame 28 by a so-called lead screw. The X-axis drive unit 30 includes a screw rod 94, a nut member 96 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 arranged along the X axis. Further, the screw rod 94 is arranged between the pair of X-axis linear motion guides 88.

The nut member 96 is screwed into 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 amount of rotation.

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 of the brackets 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 amount of rotation thereof. 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 movably supports the Z-axis moving frame 34 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 constituting the Y-axis guide mechanism 20. That is, it includes a Z-axis guide rail 106 and a Z-axis slider 108 slidably supported by the Z-axis guide rail 106 via a plurality of balls (not shown). The Z-axis guide rail 106 is laid on the X-axis moving frame 28 and is arranged along the Z-axis.

The Z-axis table 102 is formed in the shape of a rectangular flat plate. 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 in parallel with the XX 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 movably supported along the Z-axis.

The Z-axis moving frame 34 is movably supported by a pair of Z-axis linear motion guides 104, but since the installation interval of the pair of Z-axis linear motion guides 104 is short, deformation of the Z-axis moving frame 34 is a problem. Will never be.

The Z-axis drive unit 36 moves the Z-axis moving frame 34 along the Z-axis by a so-called feed screw. The Z-axis drive unit 36 includes a screw rod 110, a nut member 112 screwed into 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 arranged along the Z axis. Further, the screw rod 110 is arranged between the pair of Z-axis linear motion guides 104.

The nut member 112 is screwed into 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 of the brackets 116 and is 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 thereof. 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 measuring unit 38 includes a measuring unit main body 118 and a probe 120. The measuring unit main body 118 is formed in a box shape and incorporates a device for probe control (not shown). The probe 120 is arranged vertically downward along the Z axis from the measuring unit main body 118. When the Z-axis movement frame 34 is moved, the probe 120 moves along the Z-axis direction. At the time of measurement, the tip of the probe 120 is brought into contact with the work 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 work are measured from the set of the coordinate values. 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 acquired by detecting the position of the Y-axis moving frame 22 by this Y-axis scale.

Further, 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 acquired by detecting the position of the X-axis moving frame 28 by 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 acquired by detecting the position of the Z-axis moving frame 34 by this Z-axis scale.

<Action>
As described above, the measuring machine 10 of the present embodiment is configured as a three-dimensional measuring machine, and measures the shape, dimensions, etc. of the work (measurement object).

As shown in FIG. 7, the work 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 work W. That is, the probe 120 is moved, the coordinates (X, Y, Z) when the tip of the probe 120 comes into contact with the work W are detected, and the shape, dimensions, etc. of the work are measured from the set of the 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. Further, 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. Further, 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, it is highly accurate. The probe 120 can be moved to.

That is, as described above, when 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 moving frame 22 so as to be movable along the Y-axis, the Y-axis moving frame 22 is provided. Although a moment in the rolling direction is generated, the Y-axis moving frame 22 can move flexibly in the rolling direction (MR) (it can swing around the Y-axis), so that it rolls on the Y-axis moving frame 22. Even when a moment in the direction is generated, the Y-axis moving frame 22 is supported without being deformed. As a result, 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, the Y-axis moving frame 22 may be twisted or otherwise deformed unless the parallelism of the linear motion guides at both ends is maintained with high accuracy. However, by supporting one end with the Y-axis linear motion guide 44 and floatingly 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 can be absorbed. It is possible to prevent the deformation of 22.

Further, since one end is supported by the Y-axis linear motion guide 44, the straightness for the Y-axis moving frame 22 to move on the Y-axis is on the Y-axis guide rail 46 constituting the Y-axis linear motion guide 44. Will be defined by the Y-axis slider 50. Therefore, one guide rail (Y)
It travels straight in the Y-axis direction with the shaft guide rail 46) as a reference, and does not swing left or right when moving in the Y-axis direction. This makes it possible to suppress the displacement in the yawing direction. In general, it is difficult to secure straightness during movement in levitation support by air bearings, and the displacement in the yawing direction is large. Therefore, when both ends of the Y-axis moving frame 22 are levitated and supported by air bearings, the direction is slightly changed to the left and right with respect to the moving direction, and the displacement in the yawing direction becomes large. On the other hand, as in the present embodiment, by supporting one end with the Y-axis linear motion guide 44, the straightness for moving the Y-axis moving frame 22 in the Y-axis direction is the straightness of the Y-axis linear motion guide 44. It can be regulated by gender. Therefore, the Y-axis movement frame 22 moves linearly with reference to the Y-axis linear movement guide 44. As a result, the displacement in the yawing direction can be suppressed. As a result, 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 unlike the cantilever support.

Further, in general, the floating 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, so that the displacement in the yawing direction is large. Can also be suppressed.

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

Further, in the measuring machine 10 of the present embodiment, since the drive belt 78 for driving the Y-axis moving frame 22 is arranged on the Y-axis guide rail 46, the hysteresis of the reciprocating movement can be eliminated. That is, since the drive point is arranged on the line that receives the sliding resistance, the hysteresis of the reciprocating movement can be eliminated. As a result, the error due to yawing of the Y-axis moving frame 22 can be further reduced. That is, there is a difference in sliding resistance between the portion of the Y-axis linear motion guide 44 on one side and the portion of the air pad 72 on the other side, and the portion of the Y-axis linear motion guide 44 is significantly larger. When driving the Y-axis moving frame 22, by providing a driving means on the Y-axis linear movement guide 44 side having a large sliding resistance, the Y-axis moving frame 22 can be moved based on the straightness of the Y-axis linear movement guide 44. It is possible to go straight. As a result, when the Y-axis moving frame 22 moves in the Y direction, it can be prevented from moving while slightly alternating left and right. As a result, the error due to yawing of the Y-axis moving frame 22 can be further reduced.

Further, the sliding resistance can be reduced by supporting the Y-axis linear motion guide 44. As a result, heat generation of the Y-axis motor 80 can be suppressed, and deformation of the base or the like due to thermal stress can be suppressed.

When the Y-axis moving frame 22 is swingably supported in the rolling direction (MR) as in the measuring machine 10 of the present embodiment, the swing may cause an error in the contact position of the probe. Since the error change due to the swing of the Y-axis moving frame 22 has reproducibility, it can be easily corrected.

As described above, when both ends of the Y-axis moving frame are supported by the linear motion guides, or when one end of the Y-axis moving frame is supported by a pair of linear motion guides, the Y-axis moving frame is deformed (twisted). , Deflection, etc.), but the deformation changes depending on the temperature, etc. Therefore, the reproducibility of the error change is poor, and it is difficult to accurately grasp the influence on the measured 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 has reproducibility, it can be corrected with high accuracy by applying a generally known correction technique.

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

Further, according to the measuring machine 10 of the present embodiment, since the Y-axis moving frame 22 is formed in an L shape, the weight of the Y-axis moving frame 22 can be reduced. As a result, the moment of inertia during acceleration / deceleration can be reduced, and the dynamic displacement (vibration) in the pitching direction can be reduced. In addition, the visibility of the measurement area from the side can be improved.

Further, according to the measuring machine 10 of the present embodiment, the work mounting surface 14A of the surface plate 14 is used as the guide surface of the air pad 72. As a result, it is not necessary to separately provide a guide surface, and the configuration can be simplified. Further, since the work mounting surface of the surface plate is generally flattened with high accuracy, the Y-axis moving body can be guided with high accuracy.

Further, by using the work mounting surface 14A of the surface plate 14 as the guide surface of the air pad 72, the following effects can be obtained independently. The reference surface of the work in the Z direction is the work mounting surface 14A of the surface plate 14. The height can be defined with reference to the work mounting surface by bringing the probe 120 into contact with the work mounting surface 14A and setting the contact point as 0 point. On the other hand, the reference surface of the Y-axis moving frame 22 including the probe 120 is also the work mounting surface 14A. The Y-axis moving frame 22 is configured to constantly move up and down with respect to the work mounting surface 14A by the levitation force of the air pad 72, and the Y-axis linear motion guide 44 side, which is one of the support points, is the Y-axis guide rail 46. It is configured to swing (rotate) around the center of. For example, even when the parallelism between the Y-axis guide rail 46 and the work mounting surface 14A of the surface plate 14 is not ensured, the work mounting surface 14A is provided under a constant levitation force formed by the air pad 72. The Y-axis moving frame 22 is lifted as a reference and is adjusted by swinging (rotating) at the portion of the Y-axis guide rail 46, so that the Y-axis moving frame 22 follows without bending and deforming. Therefore, since the work and the probe 120 are based on the work mounting surface 14A, accurate measurement can be performed under the same reference surface.

Further, since the reference surface for measurement is defined as one surface for both the work and the probe 120, control and management can be facilitated, and even if there is a slight secular change of the device, it can be sequentially configured. , Highly accurate measurement can be ensured for a long period of time.

Further, in the measuring machine 10 of the present embodiment, since the Y-axis linear motion guide 44 is arranged above the tip of the probe 120, the entire Y-axis movement mechanism can be configured to be hard to fall down. As a result, 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 for supporting the Y-axis moving frame 22. Strictly speaking, there are two fulcrums, the part of the Y-axis guide rail 46 and the part of the work mounting surface 14A 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 the portion of the Y-axis guide rail 46. On the other hand, it is most desirable from the viewpoint of measurement error that the position of the center of gravity in the movement in the Y-axis direction is near the tip of the probe 120. 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 position of the fulcrum that slides by such a drive mechanism, the entire Y-axis movement mechanism can be made to have a structure that does not easily collapse. And, by making the structure hard to fall down like this, it is possible to achieve the effect that the error in the pitching direction (the error of swinging in the front-back direction when moving) can be remarkably reduced. As described above, by disposing the Y-axis linear motion guide 44 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 arranged above the tip of the probe 120, the following effects are obtained. When the Y-axis guide rail 46 is arranged above the tip of the probe 120, the measurement site of the work is two fulcrums (the portion of the Y-axis guide rail 46) that support 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 measurement site of the work at an approximately intermediate position between the two fulcrums does not promote minute vibrations or minute displacements at each fulcrum, and is canceled out or at least reduced. It will be. In the case of a bridge-type measuring machine or a gantry-type measuring machine, the measurement sites of the work are located farther apart than the positions of the two fulcrums. Therefore, there is a problem that a small amount of vibration of the fulcrum portion is promoted by the moment, resulting in a larger error. However, when the Y-axis linear motion guide 44 is arranged above the tip of the probe 120, the problem of promoting vibration and displacement does not occur.

In order to bring the position of the center of gravity closer to the tip of the probe 120, it is preferable to attach the Y-axis slider 50 to the vicinity of substantially the same surface 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 moves vertically downward, and a control device for the probe 120 is mounted in the vicinity of the probe to lower the center of gravity.

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

As shown in the figure, the measuring machine 10A of the present embodiment is different from the measuring machine 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 the structural differences from the measuring machine 10 of the first embodiment will be described, and the same or corresponding configurations as the measuring machine 10 of the first embodiment are designated by the same reference numerals. Therefore, the description thereof will be omitted.

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

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 the Y-axis column.

In the Y-axis moving frame 22, one of the support columns 22B is floated and supported on the surface plate 14 by the air bearing 70, and the other support column 22C is movably supported in the Y-axis direction by the Y-axis guide mechanism 20.

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

The Y-axis linear motion guide 44 includes a Y-axis guide rail 46 and a Y-axis slider 50 slidably supported by 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.

In the Y-axis moving frame 22, the lower end of one of the support columns 22C is fixed to the Y-axis table 42 and is movably supported in the Y-axis direction.

As described above, in the measuring machine 10A of the present embodiment, the Y-axis moving frame 22 is also movably supported in the Y-axis direction by one Y-axis linear motion guide 44 and the air bearing 70. This enables the Y-axis moving frame 22 to move flexibly in the rolling direction (MR), and can support the Y-axis moving frame 22 without causing deformation.

Further, in the measuring machine 10A of the present embodiment, since the Y-axis moving frame 22 is formed in a portal shape, 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 configured to be installed on the board 14.

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

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

The Y-axis moving frame 22 is formed in the shape of a prismatic bar. That is, the Y-axis moving frame 22 of the measuring machine 10 of the first embodiment is formed in substantially the same shape as the case where the Y-axis moving frame 22 is composed of only the beam portion 22A.

Since the Y-axis moving frame 22 is formed in a linear bar shape in this way, the measuring machine 10B of the present embodiment is provided with a pair of Y-axis columns on the surface plate 14. 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 like the Y-axis column 16 of the measuring machine 10 of the first embodiment. Then, the first Y-axis base 18 is horizontally supported on the upper portion.

The second Y-axis column 17 is also formed in a V shape like the first Y-axis column 16. A second Y-axis base 19 is horizontally supported on the upper portion of 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. Therefore, the upper surface 19A of the second Y-axis base 19 is formed smoothly. Further, in the second Y-axis base 19, the upper surface 19A is horizontal (X).
It is supported by the second Y-axis column 17 so as to be (parallel to the Y-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 on the guide surface (upper surface 19A of the second Y-axis base 19) by the air bearing 70. Is surfaced and supported.

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

The Y-axis linear motion guide 44 includes a Y-axis guide rail 46 and a Y-axis slider 50 slidably supported by 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 is movably supported in the Y-axis direction.

The air bearing 70 includes an air pad 72, and floats and supports the other end of the Y-axis moving frame 22 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 the 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 air pad 72 and the upper surface 19A of the second Y-axis base 19, and the Y-axis moving frame. The other end of the 22 is floated and supported with respect to the upper surface 19A of the second Y-axis base 19.

As described above, in the measuring machine 10A of the present embodiment, the Y-axis moving frame 22 is also movably supported in the Y-axis direction by one Y-axis linear motion guide 44 and the air bearing 70. This enables the Y-axis moving frame 22 to move flexibly in the rolling direction (MR), and can support the Y-axis moving frame 22 without causing deformation.

Further, in the measuring machine 10B of the present embodiment, since the Y-axis moving frame 22 has a bar shape, the weight of the Y-axis moving frame 22 can be reduced. This makes it possible to reduce the moment of inertia during acceleration / deceleration.

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

On the other hand, in the measuring machine 10B of the present embodiment, 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, so that they are on the side. The visibility of the measurement area from the side is reduced.

Therefore, in consideration of visibility and 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, a guide rail (Y-axis guide rail 46) is slidably supported by the guide rail via a rolling element. A linear motion guide (Y-axis linear motion guide 44) composed of a rail slider (Y-axis slider 50) is adopted, but a support mechanism that supports one end of the Y-axis moving frame 22 along the Y-axis is used for this. Not limited. A structure that can swingably support the Y-axis moving frame 22 around the Y-axis when the other end is floated and supported by an air bearing may be used. For this purpose, one guide rail and a slider slidably supported by the guide rail are provided, and the slider is supported so as to be swingable in the rolling direction with respect to the guide rail (swaying in the rolling direction). Any structure is acceptable). In this case, it is preferable that the configuration is strong against displacements other than the rolling direction, that is, displacements in the pitching direction and the yawing direction. As a result, 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.

Further, in the above embodiment, the Y-axis slider 50 is belt-driven to move the Y-axis moving frame 22 in the Y-axis direction, but the means for driving the Y-axis moving frame 22 (Y-axis driving means). Is not limited to this. The configuration may be such that the Y-axis moving frame 22 can be moved 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.

The Y-axis driving means is preferably configured to drive the Y-axis slider 50 to move the Y-axis moving frame 22. By driving the Y-axis slider 50, the Y-axis moving frame 22 can be made to go straight based on the straightness of the Y-axis guide rail 46, and yawing of the Y-axis moving frame 22 can be prevented. can. This effect is independent of the effect of swingably supporting the Y-axis moving frame 22 with the support portion of the Y-axis slider 50 as a fulcrum. In a measuring machine having a measuring unit in the center, such as the measuring machine 10 of the above embodiment, one end is supported by a slider sliding along a guide rail and the other end is supported by an air pad as a means for supporting the measuring unit. It has a mechanism to support levitation, and by providing a drive system on the slider side, it has the 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 into consideration the balance of the sliding resistance and the balance of the sliding resistance, the Y-axis moving frame 22 is made to go straight while reducing the moment of inertia that slightly changes the direction in the left-right direction. As a result, it produces a unique action and effect of eliminating the error due to yawing.

10, 10A, 10B ... Measuring machine, 12 ... Stand, 12A ... Fixing leg, 12a ... Foot, 12B ... Fall prevention leg, 12b ... Foot, 14 ... Plate, 14A ... Top surface (guide surface) , 16 ... Y-axis column, first Y-axis column, 16A ... Y-axis column base, 16B ... Y-axis column strut, 17 ... second Y-axis column, 18 ... Y-axis base, first Y-axis Axis base, 19 ... 2nd Y-axis base, 19 ... Upper surface (guide surface) of 2nd 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 moving frame, 30 ... X-axis drive unit, 32 ... Z-axis guide mechanism, 34 ... Z-axis moving frame, 36 ... Z-axis drive unit, 38 ... Measuring unit, 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 ... slider body main girder, 54C ... legs of the 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-axis motor, 100 ... bracket, 102 ... Z-axis table, 104 ... Z-axis linear motion guide, 106 ... Z-axis guide rail, 108 ... Z-axis slider, 110 ... screw rod , 112 ... nut member, 114 ... Z-axis motor, 116 ... bracket, 118 ... measuring unit body, 120 ... probe

Claims (1)

In a coordinate measuring machine that measures a workpiece placed on a surface plate having a workpiece mounting surface parallel to the X-axis and the Y-axis with a probe.
With the Y-axis moving body equipped with the probe,
A Y-axis linear motion guide arranged at a position higher than the surface plate along the Y-axis and supporting one end of the Y-axis moving body so as to be movable in the Y-axis direction.
A Y-axis driving means provided on the Y-axis linear motion guide side and moving the Y-axis moving body along the Y-axis linear motion guide.
An air bearing that floats and supports the other end of the Y-axis moving body with a part of the surface plate as a guide surface.
Equipped with
The Y-axis drive means
When viewed from the X-axis direction, it is provided at a position shifted in the Z-axis direction perpendicular to both the X-axis and the Y-axis with respect to the Y-axis linear motion guide, and is provided at intervals in the Y-axis direction. And a pair of pulleys having a rotation axis parallel to the X axis ,
The drive belt wound around the pair of pulleys and
A motor that rotates and drives one of the pair of pulleys,
Equipped with
A coordinate measuring machine in which the drive belt is arranged on the same straight line as the Y-axis linear motion guide when viewed from the Z-axis direction perpendicular to both the X-axis and the Y-axis.

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