JPH02247519A - Three-dimensional measuring instrument - Google Patents

Abstract

PURPOSE:To displace a measurement and detection part almost linearly and accurately measure a body to be measured even if a guide member is bent or strained by supporting the guide member which guides a driving means on a base body through a support means which has specific rigidity. CONSTITUTION:The measurement and detection part 112 which is movable in the directions of X, Y, and Z axes as three orthogonal axes measures the shape, etc., of the body W to be measured. Then a Y-axial moving member 50 is provided movably in a specific direction along guide rails 20 as the guide member provided on a couple of support bases 11 as base bodies. Further, prismatic bodies 48 as guide members are arranged almost in parallel to the rails 20 and the support means 30 support the prismatic bodies 48 on the support bases 11 in displaceable states with specific rigidity. Further, the moving members 50 are provided with Y axial driving means 60 which move the moving members 50 in specific directions. This driving means 60 is engaged with the prismatic bodies 48, which are engaged with the driving means 60 to move the moving members 50 in the specific directions according to the driving of the driving means 60.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a three-dimensional measuring machine, and in particular, it is movable in any direction (predetermined direction) of three orthogonal axes: X, Y, and Z axes. The present invention relates to an improvement in a driving means for moving a movable member, which is shaped like an object, in a predetermined direction along a guide member, and a guide member to which the driving means is engaged.

[Background technology]

Conventionally, various three-dimensional measuring machines have been proposed as devices for accurately measuring the shape, dimensions, etc. of an object to be measured. Some three-dimensional measuring machines of this type are equipped with a drive device for automatically feeding a moving member movable in a predetermined direction.

Drive devices for such three-dimensional measuring machines include those using a rack and pinion, and those using a feed screw shaft. However, in the former case, the straightness of a general rack is not necessarily sufficient, and it is not necessarily suitable as a drive device for a coordinate measuring machine that requires straightness on the order of several microns. It would be extremely expensive to process it to a straightness that corresponds to performance. In addition, in the latter case, not only is it difficult to obtain the straightness of a long screw shaft, but also a moment is generated by the screw shaft and a force is applied to the moving member in the rotational direction. It wasn't always enough.

For this reason, it is conceivable to use a guide member having guide surfaces on both sides without using a rank or a screw shaft, and to move the movable member by holding this guide member between rolling rollers.

However, in this case, a new problem arises in that parallelism of the guide surfaces on both sides of the guide member is required, and the machining thereof is troublesome.

In order to solve this problem, we have developed a guide rail (guide member).
There is a drive device for a three-dimensional measuring machine that minimizes the influence on the straightness of the moving member even if the parallelism on both sides is poor, and the technical idea thereof is disclosed in Japanese Patent Application Laid-Open No. 62-235513. ing.

The idea behind this idea is to provide sliding guides on both sides of a base placed on the floor, install guide rails on these sliding guides, and move the main carriage (moving member) along the guide rails. In addition to being movable, a swinging body supported by a pivot is provided at a portion of the main carriage corresponding to the guide rail. This rocking body is pivotally supported to be able to swing toward and away from the guide rail, and the guide rail is pressed and held by a drive rotating body (a pair of rollers) provided on one side of the rocking body. The structure is as follows. Further, an air pad for injecting air toward the sliding guide part is provided at the lower part of the main carriage, while
A central carriage (moving member) is mounted on the upper part of the main carriage, and is displaceable in a substantially horizontal direction and has a measurement detection section.

In such a three-dimensional measuring machine, when the central carriage is displaced in the horizontal direction in order to measure the object to be measured, the weight of the central carriage is exerted in the direction of displacement, causing the main carriage to is (lJt <
However, by operating the air pad around this time, the straightness and parallelism of the main carriage can be maintained to enable precise measurement.

[Problem to be solved by the invention]

However, even if the guide rail is arranged approximately linearly with respect to the sliding guide part, if the guide rail is bent or distorted due to conditions such as room temperature and humidity, the guide rail will move along the sliding guide. Since the main carriage moves along this guide rail, the main carriage is displaced by a minute distance by the amount of deflection and distortion of the guide rail, and as a result, the measurement detection section is also displaced by that amount. This exposes the drawback that precise measurement is difficult.

SUMMARY OF THE INVENTION An object of the present invention is to provide a three-dimensional measuring machine that allows precise measurement of an object to be measured by displacing a measurement detection part substantially linearly even if the guide member is bent or distorted. .

[Means to solve the problem]

The present invention aims to achieve the above object by correcting the deflection of the guide member by supporting the guide member, which is provided substantially parallel to the guide member, in a so-called floating manner with a predetermined rigidity using a support means. .

Specifically, the present invention involves a measurement detecting section that is movable in the X, Y, and Z axes, which are three axes orthogonal to the object, to determine the shape of the object. In a coordinate measuring machine for measuring, a movable member is provided so as to be movable in a predetermined direction along a guide member provided on a base body, and a guide member is disposed on the base body approximately parallel to the guide member, and this guide member is A supporting means is provided to displaceably support the base body with a predetermined rigidity, and a driving means for moving the moving member in a predetermined direction is provided on the moving member, and the driving means is engaged with the guide member. The three-dimensional measuring machine is characterized in that the movable member can be moved in a predetermined direction in accordance with the drive of the drive means by engagement of these guide members with the drive means.

In the present invention, the guide member is preferably a prismatic body, and the support means includes an elastic support portion equipped with a compression coil spring that supports one end of the guide member so as to be displaceable in a substantially vertical direction, and the other end of the guide member. It is preferable to include a spherical hair ring that swingably supports the end.

Furthermore, in the present invention, the driving means includes a pair of rollers that can roll while holding the guide member therebetween, and a roller holding unit that holds the pair of rollers in a rollable manner and in contact with and away from the guide member. and a suppressing member that urges the pair of rollers to sandwich the guide member via the roller holding member, and a rotational drive source connected to one of the rollers of the pair of rollers. Preferably, the pressing member of the driving means includes a plurality of disc springs.

Furthermore, the moving member in the present invention may be a moving member that moves in any direction of the X, Y, or Z axes, as long as the present invention is applied to one or more of these directions.

[Effect]

In the present invention, when the driving means is driven, the driving means moves along the guide member with which the driving means is engaged, and accordingly, the moving member provided with the driving means also moves along the guide member. and move. During this movement,
Even if the guide member is bent or the parallelism between the guide member and the guide member is poor, the guide member will
Due to the action of the displaceable support means, the movable member is moved in a straight line along the guide member, correspondingly being displaced accordingly.

Therefore, the measurement detection section can also be accurately moved to a predetermined position, and precision measurement of the object to be measured can be performed.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows the overall configuration of a coordinate measuring machine 10 according to this embodiment.

The three-dimensional measuring machine 1O includes a pair of support stands 11 as base bodies arranged at a predetermined distance apart, and these support stands 11
The beam 13 is placed on each of the two front and rear legs 12 with a length of 1l.
lz, fixedly configured.

Here, since the pair of left and right support stands tt have the same configuration except that their arrangement positions are reversed, only one of them will be explained below, and the explanation of the other will be made only if necessary. The same reference numerals are given to the same constituent parts, and the explanation thereof will be omitted.

The beam 13 forms a step along its longitudinal direction, and a guide rail 20 as a guide member is placed on the upper step surface 13A, and is supported via a support means 30 on the lower step surface 13B. A prismatic body 48 is provided as a guide member.

The support means 30 includes an elastic support part 31 that elastically supports one end of the prismatic body 4 via a mounting plate 32, and swingably supports the other end of the prismatic body 4B, as will be described in detail later. A spherical bearing 41 supports a prismatic body 48, which is disposed substantially parallel to the guide rail 20, so as to be movable in either the vertical or horizontal directions relative to the guide rail 20.

The guide rail 20 has groove-shaped notches 20B formed along both longitudinal sides 2OA thereof. The projections on one side of a plurality of engagement pieces 22 arranged on the upper surface 13A of the beam 13 are engaged in the notch 20B, and the protrusions on one side of the engagement pieces 22 are inserted through the engagement pieces 22. By screwing a fixing bolt (not shown) into the upper surface 13A of the beam 13, the guide rail 20 is fixed to the beam 1 by the protrusion of the engagement piece 22.
It is designed to be pressed and fixed on the 3rd side.

Between the plurality of engagement pieces 22, a plurality of pressing members 25 are provided on the upper surface 13A of the beam 13, each of which constantly presses the side surface 2OA of the guide rail 20 toward the center of the guide rail 20. Due to the action of the engaging piece 22 and the pressing member 25, the guide rail 20 is fixed on the upper surface 13A of the beam 13 with the correct straightness.

A Y-axis moving member 50 made of a concave frame is placed on the pair of straightened guide rails 2o so as to be slidable in a predetermined direction in a horizontal plane, that is, in the Y-axis direction. This Y-axis moving member 50 is constructed by passing a crossbeam 52 between a pair of legs 51.
Y-axis driving means 60 for driving the shaft moving member 50 in the Y-axis direction
are provided for each.

As will be described in detail later, the Y-axis drive means 60 includes a servo mokuro 2 as a rotational drive source supported by the Y-axis moving member 50 via a bracket 61, and a roller holder also supported via the bracket 61. A member 63 is provided. The roller holding member 63 includes a pair of rollers 64, one of which is driven by the motor 62,
This pair of rollers 64 clamps the prismatic body 48 with a predetermined pressing force via a pressing member 76 which will be described later. As a result, when the motor 62 is driven, the roller pair 64 rolls along the prismatic body 48, and the Y-axis moving member 50 moves toward the guide rail 2.
It is designed to move along 0.

An X-axis moving member 80 is placed on the cross beam 52 of the Y-axis moving member 50 so as to be movable along the cross beam 52 in a direction perpendicular to the Y-axis direction, that is, in the X-axis direction. This X
The axis moving member 80 includes an X-axis driving means 87 that moves the X-axis moving member 80 in the X-axis direction along the crossbeam 52, and this X-axis driving means 87 is driven by a servo motor 8 as a rotational drive source. In addition to the Y-axis driving means 60, the Y-axis driving means 60 has the same components as the Y-axis driving means 60. That is, the X-axis drive means 8
7 is a prismatic body similar to the prismatic body 48 on the beam 13 (
(not shown), and this prismatic body is provided on the rear surface in FIG. 1 of the cross beam 52 of the Y-axis moving member 50, and is adapted to be driven along this prismatic body. put it here,
The cross beam 52 of the Y-axis moving member 50 serves as a base and a guide member for the X-axis moving member 80.

The X-axis moving member 80 includes a mounting plate 81 that is vertically disposed on the front side of the Y-axis moving member 50 in FIG. Square-shaped support frames 82 are provided at the top and bottom of the mounting Fi, 81, respectively, and a square shaft-shaped The Z-axis spindle Ill is in the vertical direction, that is,
It is supported slidably in the axial direction. This Z-axis spindle 111 is detachably equipped with a measurement detection section 112 consisting of a touch sensor or the like at its lower end, and includes the Z-axis spindle 111 and measurement detection section 112 to move the X-axis moving member 1.
10 are configured.

The Z-axis spindle 111 is equipped with an air balance device (not shown) inside, and this air balance device includes a compressed air supply section 103 provided on a support plate 84 fixed on the upper support frame 82. Air (compressed air) is supplied. Therefore, this air causes the Z-axis spindle 11 to
1. The weight of the X-axis moving member 110 consisting of the measurement detection unit 112 etc. is balanced, and the Z-axis spindle 111
can be smoothly moved in the X-axis direction with extremely small force.

An X-axis drive means 120 is provided between the X-axis moving member 80 and the Z-axis spindle 111. This Z axis,
The driving means 120 is configured to move the X-axis moving member 80 at the mounting +Fj
, 81 is rotatably supported by a feed screw shaft 121 made of a ball screw or the like, a servo motor 122 as a rotational drive source for rotationally driving the feed screw shaft 121, and a servo motor 122 fixed to the Z-axis spindle 111. together with the feed screw shaft 12
1 and a NAND member 123 screwed together.

By rotating the servo motor 122, the nut member 123 screwed onto the feed screw shaft 121 is rotated to Z.
axially, thereby causing the Z-axis spindle 111
can be moved in the Z-axis direction. Here, the X-axis moving member 80 is
It plays the role of a base and a guide member.

On the other hand, the three-dimensional measuring machine 10 has the X-axis driving means 60
, an operation means 130 for driving the X-axis drive means 87 and the X-axis drive means 120. This operating means 130 is
It has an operation panel 132 supported by a pedestal 131, and two joysticks 1 on the left and right are mounted on the operation panel 132.
33,134 are provided. One of these joysticks 133 and 134
3, when the operating lever is operated in the P direction in the figure, the X-axis driving means 60 is actuated to move the Y-axis moving member 50 in the Y-axis direction, while the joystick 133 is moved in the P direction.
When the X-axis moving member 80 is operated in the Q direction perpendicular to the X-axis direction, the X-axis driving means 87 is actuated to move the X-axis moving member 80 in the X-axis direction. Furthermore, when the other joystick 134 is operated in the R direction parallel to the P direction, the X-axis drive means 12
0 to move the Z-axis spindle 111 in the Z-axis direction.

Note that the symbol W shown by the dotted chain line in the middle of FIG. It is. Further, reference numeral 140 in FIG. 1 is a shock absorbing means that also serves as a stopper for the Y-axis moving member 50,
It is composed of a sliding shaft 142 supported by the beam 13 via a bracket 141, and a spring 143 that biases the sliding shaft 142 in the projecting direction, and absorbs the impact when the Y-axis moving member 50 comes into contact with it. The spring 143 is designed to absorb it.

2 to 5 show detailed structures of the support means 30 and the X-axis drive means 60 in this embodiment.

In FIG. 2, the elastic support portion 31 of the support means 30 includes a support plate 33 fixed on the lower surface 13B of the beam 13 on the left side in the figure, a shaft 34 erected on the support plate 33, and A pair of nuts 35 are screwed onto the top and bottom of the shaft 34, respectively.
A pair of spring receivers 36 are respectively interposed at the inner positions of the pair of NANDs 35, and are engaged from above and below with the other end of a mounting plate 32 whose one end is screwed and fixed to the prismatic body 48. and a pair of compression coil springs 38 interposed between each of these clamping members 37 and the pair of spring receivers 36, respectively. Thereby, the elastic support part 31 can support one end of the prismatic body 48, which is a guide member, so as to be able to be displaced in a substantially vertical direction.

On the other hand, the spherical bearing 41 of the support means 30
The base 42 is fixed on the lower surface 13B on the right side in the figure of 3.
, a shaft body 43 erected on this base 42 , a double-row spherical seat type hair ring body 44 engaged with this shaft body 43 , and a prismatic body 4 that supports this bearing body 44 .
8 and a bearing box 45 fixed to the right end of the prismatic body 48, and supports the other end of the prismatic body 48 in a swingable manner.

Therefore, these elastic support parts 31 and spherical bearings 4
1, the prismatic body 48 is movable in any of the vertical and horizontal directions as described above.
It is supported by 3.

In FIGS. 2 and 3, the leg portion 5 of the Y-axis moving member 50
1 via a bracket 61
0 is equipped with a servo motor 62 as a rotational drive source attached to a bracket 61, and a reducer 66 is connected to an output shaft 62A of this servo motor 62 via a coupling 65, and this reducer 66 is also connected to the bracket 61. is supported by

The rotating shaft 66A on the output side of the speed reducer 66 is connected to the drive shaft via an overload protection device 67 which slips when a torque exceeding a predetermined transmission torque is applied and prevents the transmission of torque exceeding the predetermined torque. Connected to 6B. This drive shaft 68 is rotatably supported by a fixed holder 69 of a roller holding member 63 fixed to the bracket 61. A drive roller 64A, which constitutes one of the pair of rollers 64, is fixed in the middle of the drive shaft 68 supported by the fixed holding body 69, facing the prismatic body 48 as a guide member. As shown in the enlarged sectional view of FIG. 4, the drive shaft 68 is rotatable via needle bearings 72 supported by a pair of bearing holders 71 fixed above and below the fixed holder 69, respectively. Supported.

The roller holding member 63 includes, in addition to the fixed holding body 69, bearing portions 69A formed above and below the fixed holding body 69.
The movable holder 74 is swingably supported by a pair of upper and lower arms 74A formed at one end thereof via an eccentric shaft 73 supported by the holder 74.

A driven roller 64B, which constitutes the other of the pair of rollers 64, is rotatably supported on the movable holder 74 so as to face the prismatic body 4 via a shaft 75.

As a result, the roller holding member 63 consisting of the fixed holding body 69 and the movable holding body 74 holds the roller pair 64 so as to be able to come into contact with and be separated from the prismatic body 4B, and to be able to roll. It is designed to be able to roll while holding the prismatic body 48 between them. In addition, the eccentric shaft 73 is provided with upper and lower eccentric parts 73A as shown in FIG.
By rotating the eccentric shaft 73 relative to the bearing portion 69A of the fixed holder 69, the position of the movable holder 74 relative to the fixed holder 69 and, in turn, the position of the driven roller 6 relative to the prismatic body 48 is adjusted.
The position of 4B can be adjusted, and the prismatic body 4B can be appropriately held between the pair of rollers 64.

A pair of pressing members 76 are interposed between the end of the movable holding body 74 opposite to the arm portion 74A and the fixed holding body 69 at upper and lower positions with the prismatic body 48 in between. As shown in an enlarged view in FIG. 5, this pressing member 76 includes a bolt 77 disposed through the fixed holder 69 and the movable holder #74, and nuts screwed into both ends of the bolt 77, respectively. A plurality of nuts are interposed between the nut 7 and the fixed holder 69 and the movable holder 74 at both ends thereof, and urge the fixed holder 69 and the movable holder 74 in a direction toward each other. It is composed of a disc spring 79. The pressing force by these plural disc springs 79 is
It is transmitted to the roller pair 64 via the fixed holder 69 and the movable holder 74, respectively, and the prismatic body 48 is
to a predetermined pressing force, for example, about 10010 per unit area.
It is designed to clamp with such force that it becomes 0O.

Therefore, by driving the servo motor 62, the coupling 65, the reducer 66, the overload protection device 67 and the drive shaft 6
When the drive roller 64A is driven through the lens, the roller pair 64 rolls along the side surface of the prismatic body 4, and along with this rolling, the Y-axis drive means 60 and this Y-axis drive means 60 are A Y-axis moving member 50 attached via the Y-toro 1 is moved forward and backward along the guide rail 20 in the Y-axis direction.

FIG. 6 shows an enlarged view of the portion where the lower part of the leg portion 51 of the Y-axis moving member 50 is engaged with the guide rail 20. At the bottom of this leg portion 51, when the X-axis moving member 80 is displaced in the X-axis direction along the crossbeam 52 of the Y-axis moving member 50, a Y-axis moving member 50 based on the movement of the X-axis moving member 80 is provided. An air bearing means 150 is provided to prevent tilting. This air hair ring 150 has a guide rail 20 at the bottom of the Y-axis moving member 50.
including an air ejection surface 151 formed to surround the
This air ejection surface 151 is provided with a plurality of air ejection holes 152 . These plurality of air jet holes 152 are connected by a connecting space 153, and a nozzle 154 is attached to a part of the connecting space 153, and a pressure supply source (not shown) is connected to this nozzle 154. .

Therefore, when air from the pressure supply source is supplied to the connection space 153 through the nozzle 154, this air is ejected from each air ejection hole 152 to the guide rail 20, and the guide rail 20 and the Y-axis moving member 50 and maintains a state of isolation for a predetermined period of time.

Next, the operation of this embodiment will be explained.

To measure the object to be measured W, first, a pressure supply source (not shown) is driven, and the nozzle 15 of the air bearing 150 is heated.
Air is supplied to the connection space 153 through the connection space 153. As a result, air is injected from the air jet hole 152 toward the guide rail 20, so that the Y-axis moving member 50 and the guide rail 2
0 and a predetermined period of isolation, preferably 3 to 5.
Micrometer spacing is maintained.

Then the joystick 133.1 of the operating means 130
34 is operated L7, Y-axis moving member 50, X-axis moving member 80
and move the X-axis moving member 110, and move the Z-axis spindle 1.
The measurement is carried out while the measurement detecting section 112 attached to the object W is brought into contact with a predetermined point to be measured of the object W to be measured.

When operating the joysticks 133 and 134, when the one joystick 133 is moved to one side in the P direction, that is, in the P direction, the Y-axis moving member 50 moves in the direction of X1.
If you move it in the direction P3, which is the other side, it will move in the Y direction. Furthermore, when moved in the R1 direction on one side of the Q direction, the X-axis moving member 80 is moved in the X1 direction, and when moved in the Q direction, it is moved in the X8 direction, and the lever of the joystick 133 is moved to the neutral position (solid line position in the figure). When returned, the Y-axis moving member 50 and the X-axis moving member 80 stop moving in their respective moving directions.

Furthermore, when the joystick 134 is moved in the R1 direction on one side of the R direction, the X-axis moving member 110 is moved downward in the Z1 direction, and when it is moved in the other R1 direction, it is moved upward in the Z2 direction, and returned to the neutral position. and its movement stops.

In driving the Y-axis drive means 60, when the joystick 133 is operated in the P direction, the Y-axis drive means 6
The servo motor 62 of No. 0 is rotationally driven, and its output shaft 62
The rotation of A is transmitted to the drive shaft 68 via the coupling 65, the reduction gear 66, and the overload protection device 67. As the drive shaft 68 rotates, the drive roller 64A integrally fixed to the drive shaft 68 is also rotated. At this time, the drive roller 64
A and the driven roller 64B sandwich the prismatic body 48 by the action of the pressing member 76, so the rotation of the driving roller 64A causes the driving roller 64A and the driven roller 64B to rotate along the Y axis along the side surface of the prismatic body 48. roll in the direction. As a result, the roller holding member 63 that holds the roller pair 64 also moves in the Y-axis direction along the prismatic body 48, and this roller holding member 63 is attached via the bracket 6.l. The member 50 will also move in the Y-axis direction.

When moving the Y-axis moving member 50 in the Y-axis direction, air is supplied to the air hair ring 150 formed at the lower part of the leg portion 51 of the Y-axis moving member 50 as described above. The moving member 50 will move smoothly along the guide rail 20.

At this time, if the prismatic body 48 is bent or distorted or is not parallel to the guide rail 20, the prismatic body 48
is displaced in a direction that corrects the deflection, etc. of the prismatic body 48 by the action of the support means 30 that supports the prismatic body 48 with a predetermined rigidity, and the Y-axis moving member 50 is moved smoothly regardless of the deflection, etc. becomes. This displacement of the prismatic body 48 is absorbed by the elastic support of the compression coil spring 38 of the elastic support portion 31 constituting the support means 30 and the rotational support of the spherical bearing 41 by the bearing body 44 .

Further, the X-axis moving member 80 moves along the crossbeam 52 of the Y-axis moving member 50 by the action of the X-axis driving means 87, and the Y-axis moving member 50 moves the side on which the X-axis moving member 80 moves downward. If the air bearing 1
50 prevents the inclination, and this also allows the Y-axis moving member 50 and the X-axis moving member 80 to move smoothly.

In this way, the y-, x-, and z-axis moving members 50°80.1
10 is moved to cause the measurement detection section 112 to be involved in the measurement point of the object W to be measured, the abutment position of the measurement detection section 112 is determined by a calculation means (not shown) in the x and y directions from the reference point, respectively.
, are calculated as z-axis coordinates, that is, three-dimensional coordinates, and the dimensions, shape, etc. of the object W to be measured are measured.

In the measurement, the Y-axis moving member 50 is connected to the guide rail 20.
However, since the guide rail 20 is fixed to the upper surface 13A of the beam 13 while maintaining its straightness by the engaging piece 22 and the pressing member 25 as described above, the Y guided by the guide rail 20 The shaft moving member 50 is also guided linearly, and measurement errors do not occur.

According to this embodiment as described above, there are the following effects.

That is, since the present embodiment is provided with the support means 30 for absorbing the displacement of the prismatic body 48, it is possible, for example, when the guide rail 20 and the prismatic body 48 are not disposed substantially parallel to the horizontal direction. In this case, even if the Y-axis moving member 50 is displaced in the Y-axis direction, the spherical bearing 4
1, the correction can be made substantially parallel.

Furthermore, in a case where the guide rail 20 and the prismatic body 48 are not disposed substantially parallel to the vertical direction, even if the Y-axis moving member 50 is similarly displaced in the Y-axis direction, the non-parallel portion can be elastically supported. This can be corrected by a pair of upper and lower compression coil springs 38 of the portion 31.

Furthermore, when the prismatic body 48 is bent or distorted due to external conditions such as room temperature and humidity, the Y-axis moving member 50
Even if it is displaced, vertical and horizontal deflection, distortion, etc. can be instantly corrected by the action of the spherical bearing 41 and the compression coil spring 38 of the elastic support section 31.

As a result, no more load than necessary is applied to the Y-axis moving member 50, making it possible to maintain the interval defined by the air bearing 150 constant at all times. This makes it possible to accurately measure the dimensions, shape, etc. of the object W to be measured.

Further, the support means 30 of the prismatic body 48 adjusts the position of the nut 35 screwed into the shaft 34 of the elastic support part 31,
The rigidity of the support means 30 can be changed as appropriate by changing the spring constant by replacing the compression coil spring 38, thereby making it possible for the Y-axis moving member 50 to move smoothly at all times. Further, since the structure of the support means 30 is composed of the elastic support part 31 and the spherical bearing 41, which have a relatively simple structure, it can be provided at low cost.

Further, the Y-axis driving means 60 engaged with the prismatic body 48 includes a roller holding member 63 consisting of a movable holding body 74 that is provided to be freely openable and closable via an eccentric shaft 73 with respect to a fixed holding body 69, and A driving roller 64A and a driven roller 64B are rotatably supported on the fixed holding body 69 and the movable holding body 74, respectively, and further, these driving roller 64A and driven roller 64B are pressed into a rectangular column by a predetermined pressing force by a pressing member 76. Since the body 48 is sandwiched, it can be driven reliably and does not cause backlash unlike the conventional combination of rack and pinion. Similarly, unlike the conventional feed screw shaft, no rotational moment is generated.

Furthermore, since a movable holder 74 is attached to the fixed holder 69 of the roller holding member 63 via an eccentric shaft 73, the position of the driven roller 64B can be adjusted by adjusting the amount of eccentricity of the eccentric shaft 73. This allows the prismatic body 48 to be properly held between the drive roller 64A.

Furthermore, since the series of members from the servo motor 62 to the roller pair 64 of the Y-axis drive means 60 is composed of relatively simple members, the Y-axis drive means 60 can be manufactured at low cost.
As a result, the three-dimensional measuring machine 10 can be manufactured at low cost.

Note that the present invention is not limited to the above embodiments (
Of course, various improvements and changes in design are possible without departing from the gist of the invention.

For example, in the embodiment described above, a large coordinate measuring machine 10 that measures a relatively large member as the object to be measured W has been described, but the present invention is not limited to this.
It can also be applied to coordinate measuring machines that measure relatively small objects. Furthermore, in the embodiment described above, the coordinate measuring machine 10 is described in which the Y-axis drive means 60 and the X-axis drive means 87 both include a pair of rollers 64 that sandwich the prismatic body 48, but these drive means 60.87 are Not necessarily both,
They do not need to be provided in the same structure, and either one may have the structure of the above embodiment. On the other hand, the Z-axis spindle 11
The Z-axis driving means 120 for driving the Y-, X-, and Z-axis moving members 50 and 80 may also have a structure including a prismatic body 48 and a pair of rollers 64.
, 110, and the driving means also includes:
Y.

It may be any of the X- and Z-axis driving means 60, 87, and 120. In this case, the member that guides and supports the moving member is the base body. Further, the Y-axis drive means or the X-axis drive means that does not have the structure of the above embodiment may be constructed of a feed screw shaft and a nut member, similar to the Z-axis drive means 120 in the above embodiment.

Further, in the embodiment described above, the movable holder 74 is supported via the eccentric shaft 73 so as to be openable and closable with respect to the fixed holder 69 of the roller holding member 63. It is not necessary to use a simple axis. However, if the eccentric shaft 73 is used, there is an advantage that the position of the movable holder 74 with respect to the fixed holder 69 can be adjusted as described above. Furthermore, the overload protection device 67 provided in the Y-axis drive means 60 is not limited to the structure that slips when the load exceeds a predetermined value as in the above embodiment, but the overload protection device 67 is not limited to the structure that slips when the load exceeds a predetermined value as in the above embodiment, but the overload protection device 67 detects the load of the servo motor 62 by detecting current, etc. Other structures may also be used, such as a structure that automatically disconnects the clutch or the like.

Further, the support means 30 for the prismatic body 48 is not limited to the elastic support portion 31 having the compression coil spring 38 and the spherical bearing 41 as in the above embodiment, but may have other configurations. The prismatic body 4 as a guide member does not necessarily have to be a prismatic body as long as it can be supported displaceably with a predetermined rigidity.
Although a cylindrical or similar shape may be used, a prismatic body 48 has the advantage of ensuring reliable guidance. At this time, if the guide member is made into a cylinder or the like, the roller pair 6 should be adjusted according to the shape.
Of course, the shape of 4 can be changed.

In addition, the beam 13 of the support stand 11 which is arranged separately is
They may be formed integrally, but when measuring a large object W to be measured, it is advantageous that the height of the apparatus can be reduced if they are separated.

〔Effect of the invention〕

As described above, according to the present invention, since the guide member that guides the drive means is supported by the base body via the support means having a predetermined rigidity, even if the guide member is bent or deflected, This has the effect that the moving member can always be properly guided and precise measurements can be performed.

[Brief explanation of drawings]

FIG. 1 is a perspective view of the overall configuration of an embodiment of the present invention, FIG. 2 is an enlarged side view with a partially omitted and partially sectional view showing the Y-axis drive means of the embodiment, and FIG. A right side view of FIG. 2 with a part cut away, FIG. 4 is an enlarged sectional view taken along the line IV-IV of FIG. 2, and FIG. 5 is an enlarged view taken from ■ in FIG. 2.
FIG. 6 is an enlarged sectional view showing the state of engagement between the legs of the Y-axis moving member and the guide rail. DESCRIPTION OF SYMBOLS 10... Three-dimensional measuring machine, 11... Support stand as a base, 20... Guide rail as a guide member, 30...
- Support means, 31... Elastic support part, 32... Mounting plate, 38... Compression coil spring, 41... Spherical bearing, 48... Prismatic body as a guide member, 50
...Y-axis moving member, 60...Y-axis drive means, 62.
... Servo motor as a rotational drive source, 63... Roller holding member, 64... Roller pair, 65... Cambling, 76... Pressing member, 79... Belleville spring, 80...
...X-axis moving member, 87...X-axis drive means, 88...
- Servo motor as a rotational drive source, 110... Z-axis moving member, 111... Z-axis spindle, 112...
Measurement detection unit, 150... air bearing as air bearing means, W... object to be measured.

Claims (5)

[Claims] (1) A three-dimensional measuring machine that measures the shape, etc. of a workpiece by involving the workpiece with a measurement detection unit that is movable in the X, Y, and Z axes, which are three axes orthogonal to the workpiece. A movable member is provided to be movable in a predetermined direction along a guide member provided on a base, a guide member is arranged on the base substantially parallel to the guide member, and the guide member is moved in a predetermined direction with respect to the base. A supporting means for displaceably supporting the moving member with rigidity is provided, and a driving means for moving the moving member in a predetermined direction is provided on the moving member, and the driving means is engaged with the guide member, and the moving member is engaged with the guide member. A three-dimensional measuring machine characterized in that the movable member is movable in a predetermined direction in accordance with the drive of the drive means by engagement with the drive means. (2) The coordinate measuring machine according to claim 1, wherein the guide member is constituted by a prismatic body. (3) In claim 1 or 2, the support means includes an elastic support section including a compression coil spring that supports one end of the guide member so as to be displaceable in a substantially vertical direction, and the other end of the guide member. A three-dimensional measuring machine characterized by comprising a spherical bearing that is swingably supported. (4) In any one of claims 1 to 3,
The driving means includes a pair of rollers that can roll while holding a guide member therebetween, and a pair of rollers that abuts the pair of rollers against the guide member.
a roller holding member that holds the guide member in a separable and rollable manner; a pressing member that urges the pair of rollers to sandwich the guide member via the roller holding member; and a pressing member that is connected to one of the rollers of the pair of rollers. A three-dimensional measuring machine, characterized in that it is equipped with a rotary drive source. (5) The three-dimensional measuring machine according to claim 4, wherein the pressing member includes a plurality of disc springs, and the urging force of the pressing member is constituted by these disc springs.