JP5485066B2 - CMM - Google Patents

Description

  The present invention relates to a coordinate measuring machine. Specifically, the present invention relates to a CMM having an air balance mechanism in a spindle.

  In a three-dimensional measuring machine that measures the shape and dimensions of an object to be measured, an air balance mechanism is incorporated in a spindle having a probe at the tip, and the spindle balances the weight of the spindle including the probe by this air balance mechanism. Has been proposed (see Patent Document 1).

  This includes a table for placing an object to be measured, a hollow cylindrical spindle having a probe at the tip, a Z-direction drive mechanism for raising and lowering the spindle in the vertical direction (Z direction), and the table and spindle in the vertical direction. A moving mechanism having an X-direction drive mechanism and a Y-direction drive mechanism that move relative to each other in a direction orthogonal to each other (X and Y directions), and air that generates a push-up force that matches the weight of the spindle including the probe. And a balance mechanism.

  The air balance mechanism includes a cylinder provided in the spindle along the axial direction of the spindle, a piston slidably accommodated in the cylinder, and a support for supporting the piston so that the spindle can be moved up and down. A support shaft that supports the member; and a push-up force generation chamber that generates a push-up force in the spindle that is a space in a cylinder defined by the piston and that matches the weight of the spindle including the probe by the pressure of the supplied air. It is configured.

  In such a configuration, when air having a pressure corresponding to the weight of the spindle including the probe is supplied to the push-up force generation chamber in the cylinder defined by the piston, the probe is caused by the pressure of the air supplied to the push-up force generation chamber. Since the push-up force corresponding to the weight of the spindle including is generated in the spindle, the spindle can be moved up and down with a relatively light force.

JP 2003-1458581 A

  Incidentally, in the structure described above, wiring such as a power supply line and a signal line is connected to the probe attached to the tip of the spindle. If the wiring connected to the probe is routed along the outside of the spindle, it will not only look good from the design point of view, it will also interfere with the operation, and the probe will be used as the measurement site of the object to be measured. There can be a problem such as the contact of the wiring with the measurement site when contacting.

  Therefore, in the conventional structure, the wire from the probe attached to the tip of the spindle is led to the upper part of the spindle through the gap between the inner surface of the spindle and the outer surface of the cylinder, and is drawn out from there to the outside of the spindle. Since the gap between the inner surface of the spindle and the outer surface of the cylinder is narrow, it is easy to contact the cylinder during wiring. Then, an external force acts on the cylinder with the contact of the wiring, so that the cylinder is likely to be bent. If the cylinder is bent, the sliding resistance between the piston and the piston housed inside the cylinder also increases, which affects the vertical movement of the spindle and the measurement accuracy.

  The object of the present invention is to eliminate such problems, and in a configuration having an air balance mechanism in the spindle, the three-dimensional measurement has little effect on the vertical movement of the spindle and the measurement accuracy without impairing the appearance. Is to provide a machine.

  The three-dimensional measuring machine according to the present invention includes a table for placing an object to be measured, a cylindrical spindle that is supported by a support member so as to be movable up and down in a vertical direction, and has a probe at a tip, and Z that moves the spindle up and down. Weight of the spindle including the direction driving mechanism, the moving mechanism having the X direction driving mechanism and the Y direction driving mechanism for moving the table and the spindle relative to each other in a direction perpendicular to the vertical direction and perpendicular to each other, and the probe In the three-dimensional measuring machine provided with an air balance mechanism that generates a push-up force suitable for the spindle in the spindle, the air balance mechanism includes a cylinder provided along the vertical direction inside the spindle, and a slide in the cylinder. A piston housed in a movable manner, a support shaft for supporting the piston on the support member, and the piston defined by the piston And a push-up force generating chamber that generates a push-up force corresponding to the weight of the spindle including the probe by the pressure of the air supplied in the cylinder, and wiring from the probe. A guide path that leads to the outside of the spindle through the space between the inner surface of the spindle and the outer surface of the cylinder without contacting the cylinder is formed inside the spindle.

According to such a configuration, a guide path for guiding the wiring from the probe to the outside of the spindle through the space between the inner surface of the spindle and the outer surface of the cylinder without contacting the cylinder of the air balance mechanism is formed inside the spindle. Therefore, the wiring from the probe can be prevented from contacting the cylinder.
Accordingly, since no external force acts on the cylinder, it is possible to prevent a bending force from acting on the cylinder. As a result, the sliding resistance between the cylinder and the piston does not increase, so that the vertical movement of the spindle and the measurement accuracy are hardly affected. Of course, since the wiring from the probe is not wired along the outside of the spindle, the appearance is not impaired.

In the coordinate measuring machine of the present invention, a protective cylinder that covers the outer surface of the cylinder is attached to the inside of the spindle, and the guide path is formed between the outer surface of the protective cylinder and the inner surface of the spindle. Is preferred.
According to such a configuration, the guide path can be formed simply by disposing the protective cylinder so as to cover the outer surface of the cylinder inside the spindle. Therefore, since it can be configured only by newly installing a protective cylinder, it can be easily configured.

In the coordinate measuring machine according to the present invention, a wiring storage hole or a wiring storage groove for storing wiring from the probe is formed on the inner surface of the spindle so as to be separated from the outer surface of the cylinder, and the wiring storage hole or the wiring storage groove is formed. It is preferable that the guide path is formed.
According to such a configuration, the wiring storage hole or the wiring storage groove is formed on the inner surface of the spindle, and the wiring storage hole or the wiring storage groove is used as a guide path. Therefore, compared to a configuration in which a new member is added and installed. The number of parts can be reduced, and the structure can be reduced.

The perspective view which shows the three-dimensional measuring machine which concerns on this embodiment. The figure which shows a Z-axis spindle and its periphery mechanism in embodiment same as the above. The top view which shows a friction drive mechanism in embodiment same as the above. The figure which shows the modification of a taxiway in embodiment same as the above.

FIG. 1 is a perspective view showing an embodiment of a coordinate measuring machine according to the present invention.
The coordinate measuring machine 1 of the present embodiment is configured to include a table 2 on which an object to be measured is placed and a moving mechanism that moves the probe 13. As the moving mechanism, the probe 13 is moved in the Y direction. A Y-direction drive mechanism 3, an X-direction drive mechanism 7 that moves the probe 13 in the X direction, and a Z-direction drive mechanism 11 that moves the probe 13 in the Z direction are provided.

  The table 2 is formed in a quadrangular prism shape having an upper surface that has been precisely flattened to place a measurement object. For the sake of explanation, two directions orthogonal to each other on the upper surface of the table 2 are defined as an X direction (left-right direction) and a Y direction (front-rear direction), respectively, and a direction perpendicular to the upper surface of the table 2 is defined as a Z direction (up-down direction).

  The Y-direction drive mechanism 3 is paired with a Y guide rail 4 provided in the Y direction on the table 2, a Y slider 5L provided movably along the Y guide rail 4, and the Y slider 5L. And a Y slider 5R that moves in the Y direction on the table 2. An air bearing is provided between the Y guide rail 4 and the Y slider 5L and between the table 2 and the Y slider 5R, but the description thereof is omitted.

  The X-direction drive mechanism 7 includes an X beam 8 which is a longitudinal guide member supported at both ends by the Y slider 5L and the Y slider 5R, and a movable member provided to be movable along the longitudinal direction of the X beam 8. And an X slider driving means 10 for moving the X slider 9. Both ends of the X beam 8 are supported on the Y slider 5L and the Y slider 5R, and are moved in the Y direction by the drive of the Y direction driving mechanism 3. An air bearing is provided between the X slider 9 and the X beam 8, but the details are omitted.

  As shown in FIG. 2, the Z-direction drive mechanism 11 includes a Z-axis spindle 12, a guide cylinder 22 as a guide member that guides the Z-axis spindle 12 in the vertical direction, and an upper end that is swingably supported. A support shaft 28 having a piston 29 at the lower end and inserted through the Z-axis spindle 12 so as to pass near the center of gravity of the Z-axis spindle 12, and a friction drive mechanism 14 provided between the Z-axis spindle 12 and the support shaft 28. And a housing 32 for housing them.

The Z-axis spindle 12 is formed in a rectangular tube shape with a hollow inside, and is guided in the vertical direction by a guide tube 22. A probe 13 is provided at the lower end of the Z-axis spindle 12 for contacting the object to be measured and measuring the position and / or coordinates of the object to be measured.
The guide cylinder 22 is provided in the X slider 9 with the cylinder hole directed in the vertical direction, and inserts and supports the Z-axis spindle 12 through the air bearing 23 so as to be vertically movable. The air bearing 23 is formed by providing an air pad 24 in a cylindrical hole of the guide cylinder 22 and blowing air from the air pad 24 onto the sliding surface (outer surface) of the Z-axis spindle 12.

  The upper end of the support shaft 28 is supported by a support column 25 erected on the guide tube 22. The column 25 has a horizontal beam 26 at a position at least higher than the movement amount of the Z-axis spindle 12 from the guide tube 22, and a hole is provided at the intersection of the horizontal beam 26 and the movement axis of the Z-axis spindle 12. . The upper end of the support shaft 28 is inserted into the hole of the cross beam 26 and has a flange 30 having a surface orthogonal to the support shaft 28. A ball 31 is provided on the upper surface of the flange portion 30, and the ball 31 is supported by a bearing piece 27 provided on the support column 25, so that the upper end of the support shaft 28 is swingably supported.

  As shown in FIG. 3, the friction drive mechanism 14 includes a drive roller 15 and a driven roller 16 that sandwich the support shaft 28, and a motor 17 that drives the drive roller 15. The driving roller 15 and the driven roller 16 sandwich the support shaft 28 with a predetermined pressing force, and the driving roller 15 and the driven roller 16 against the support shaft 28 by the frictional force generated between the rollers 15, 16 and the support shaft 28. It is configured not to idle. The driving roller 15 and the motor 17 are provided with pulleys 151 and 171, respectively, and the power of the motor 17 is transmitted to the driving roller 15 through a belt 18 that is stretched over the pulleys 151 and 171.

An air balance mechanism 19 is provided inside the Z-axis spindle 12.
The air balance mechanism 19 includes a cylinder 20 provided in the Z-axis spindle 12 along the vertical direction, a piston 29 slidably accommodated in the cylinder 20, and a guide serving as a support member for the piston 29. A support shaft 28 supported by the cylinder 22 and the X slider 9 and a push-up force generation chamber 201 on the support shaft 28 side of the cylinder chamber defined by the piston 29 are configured. The push-up force generating chamber 201 is provided with a blow hole 21 for supplying air into the push-up force generating chamber 201. The air is supplied at a pressure that generates an upward force corresponding to the weight of the Z-axis spindle 12 by the internal pressure of the upward force generation chamber 201.

A protective cylinder 41 that covers the outer surface of the cylinder 20 is provided outside the cylinder 20. The protective cylinder 41 has a cylindrical shape with a slight gap with respect to the outer surface of the cylinder 20, and the upper end is connected and fixed to the Z-axis spindle 12.
In the gap between the outer surface of the protective cylinder 41 and the inner surface of the Z-axis spindle 12, a guide path 43 is formed for guiding the wiring 13A from the probe 13 to an outlet 42 formed at the upper end of the Z-axis spindle 12. Yes. That is, the guide path 43 for guiding the wiring 13A from the probe 13 to the outside of the Z-axis spindle 12 through the space between the inner surface of the Z-axis spindle 12 and the outer surface of the cylinder 20 without contacting the cylinder 20 is provided on the Z-axis spindle 12. It is formed inside.
The wiring 13A from the probe 13 is drawn out of the Z-axis spindle 12 from the outlet 42 formed at the upper end of the Z-axis spindle 12, and then meandered within the housing 32 for a predetermined distance, and then the X beam. 8 and is connected to a predetermined circuit.

  When measuring the position and / or coordinates of the object to be measured in the coordinate measuring machine 1 having such a configuration, the object to be measured is placed on the table 2, and the Y-direction drive mechanism 3 and the X-direction drive are driven. The mechanism 7 and the Z-direction drive mechanism 11 are driven to move the probe 13 and bring the probe 13 into contact with the object to be measured. By recording the position of the probe 13 at this time, the position and / or coordinates of the object to be measured can be measured.

  When driving the Z-direction drive mechanism 11, the drive roller 15 is rotated by driving the motor 17 to rotate. Then, since the support shaft 28 is sandwiched between the drive roller 15 and the driven roller 16, the drive roller 15 and the driven roller 16 follow the support shaft 28 by the frictional force between the rollers 15, 16 and the support shaft 28. Moved. When the driving roller 15 and the driven roller 16 are moved, the Z-axis spindle 12 is moved up and down while being guided by the guide tube 22 together with the driving roller 15 and the driven roller 16, and the probe 13 is moved.

At this time, even if the Z-axis spindle 12 is moved up and down, the wiring 13A from the probe 13 is held in the guide path 43 between the outer surface of the protective cylinder 41 and the inner surface of the Z-axis spindle 12. The wiring 13A is prevented from contacting the cylinder 20. Therefore, since no external force acts on the cylinder 20, it is possible to prevent a bending force from acting on the cylinder 20. As a result, since the cylinder 20 and the piston 29 can slide smoothly, the vertical movement of the Z-axis spindle 12 and the measurement accuracy are hardly affected. Of course, since the wiring 13A from the probe 13 is not wired along the outside of the Z-axis spindle 12, the appearance is not impaired.
In addition, in the present embodiment, the guide path 43 can be formed simply by installing the protective cylinder 41 in the Z-axis spindle 12, that is, it can be configured only by newly installing the protective cylinder 41. Easy to configure.

<Modification>
The present invention is not limited to the above-described embodiment, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.

In the embodiment, the protective cylinder 41 that covers the outer surface of the cylinder 20 is attached to the inside of the Z-axis spindle 12, and the guide path 43 is formed between the outer surface of the protective cylinder 41 and the inner surface of the Z-axis spindle 12. It is not limited to this.
For example, as shown in FIG. 4, a wiring storage hole or wiring storage groove 44 for storing the wiring 13A from the probe 13 is formed on the inner surface of the Z-axis spindle 12 apart from the outer surface of the cylinder 20, and this wiring storage hole or The wiring storage groove 44 may be formed as the guide path 43. In this way, it is not necessary to add a new part, so there is an advantage that it can be configured at low cost.

  In the above-described embodiment, the CMM provided with the friction drive mechanism 14 has been described. However, a CMM without the friction drive mechanism 14 may be used. That is, a three-dimensional measuring machine having a structure in which the Z-axis spindle 12 is manually moved up and down may be used.

  INDUSTRIAL APPLICABILITY The present invention can be used for a three-dimensional measuring machine having an air balance mechanism that facilitates vertical operability of a spindle having a probe at the tip.

1 ... coordinate measuring machine,
2 ... Table,
3 ... Y direction drive mechanism (movement mechanism),
7 ... X-direction drive mechanism (movement mechanism),
9 ... X slider (support member),
11 ... Z direction drive mechanism (movement mechanism),
12 ... Z-axis spindle,
13 ... probe,
13A ... wiring,
19 ... Air balance mechanism,
20 ... cylinder,
22 ... guide tube (support member),
28 ... support shaft,
29 ... Piston,
41 ... protective cylinder,
42 ... Drawer exit,
43 ... Taxiway,
44 ... wiring storage groove,
201: Pushing force generation chamber.

Claims (3)

A table for placing an object to be measured, a cylindrical spindle that is supported by a support member so as to be vertically movable, and has a probe at its tip; a Z-direction drive mechanism for vertically moving the spindle vertically; the table and the spindle And a moving mechanism having an X-direction drive mechanism and a Y-direction drive mechanism that move relative to each other in a direction perpendicular to the vertical direction and perpendicular to each other, and a push-up force corresponding to the weight of the spindle including the probe is generated in the spindle In a coordinate measuring machine equipped with an air balance mechanism
The air balance mechanism includes: a cylinder provided in the spindle along the vertical direction; a piston slidably housed in the cylinder; a support shaft that supports the piston on the support member; A push-up force generating chamber that is a space in the cylinder defined by a piston and that generates a push-up force corresponding to the weight of the spindle including the probe by the pressure of air supplied;
A guide path for guiding the wiring from the probe to the outside of the spindle through the space between the inner surface of the spindle and the outer surface of the cylinder without contacting the cylinder is formed inside the spindle. A three-dimensional measuring machine. The three-dimensional measuring machine according to claim 1,
A three-dimensional measuring machine characterized in that a protective cylinder covering the outer surface of the cylinder is attached to the inside of the spindle, and the guide path is formed between the outer surface of the protective cylinder and the inner surface of the spindle. The three-dimensional measuring machine according to claim 1,
A wiring storage hole or wiring storage groove for storing wiring from the probe is formed on the inner surface of the spindle so as to be separated from the outer surface of the cylinder, and the wiring storage hole or wiring storage groove is formed as the guide path. A coordinate measuring machine.

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