JPH085359A - Belt driving gear - Google Patents

Abstract

PURPOSE:To provide a belt driving gear which prevents the deformation of a guide due to the tension of a belt and in which the straightness of the guide can be maintained. CONSTITUTION:A driving pulley 13 is supported by one edge 6c of an X-axis guide 6 so as to be rotatable, a follower pulley 14 is supported by the other edge 6d of the X-axis guide 6 so as to be rotatable, and the X-axis guide 6 is surrounded by a belt 15. The center line of the X-axis guide 6 and the center line of the belt 15 are situated inside the same vertical plane, the tension of the belt 15 does not act as a bending moment in the horizontal direction with reference to the X-axis guide 6, and it acts as a compressive force in the length direction of the X-axis guide 6. As a result, the deformation in the horizontal direction of the X-axis guide 6 is hardly generated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a belt driving device, and more particularly to a belt driving device suitable as a driving device for a three-dimensional measuring device.

[0002]

2. Description of the Related Art FIG. 5 is a perspective view showing a conventional belt driving device, and FIG. 6 is a perspective view showing a three-dimensional measuring device having the belt driving device shown in FIG.

A gate-type structure 207 is attached on a surface plate 202 on which an object to be measured is placed. Gate structure 207
Is composed of a support column 204, a support column 205, and an X-axis guide 206 bridged above the support columns 204, 205. A Y-axis guide rail 203 is laid on one side of the surface plate 202, and a lower portion of a column 205 is fitted on the Y-axis guide rail 203 so as to be movable in the Y-axis direction via an air bearing (not shown). The lower part of the column 204 is movable via an air bearing (not shown), and the X-axis guide 206
An X-axis carriage 208 is movably attached to the X-axis carriage 20 via an air bearing (not shown).
Reference numeral 8 supports a Z-axis spindle 209 via an air bearing (not shown) so as to be movable in the Z-axis direction. A tracing stylus 210 is attached to the lower end of the Z-axis spindle 209.

In this three-dimensional measuring device, coordinate measurement is performed on the shape and size of the object to be measured from the relative movement amount of the probe 210 with respect to the object to be measured on the surface plate 202.

When an error occurs between the straight line (each axis) and the trajectory of the tracing stylus 210 that moves along each of the X, Y, and Z axes,
The error appears as a measurement error. Therefore, in order to perform highly accurate coordinate measurement, X, X
High flatness or straightness along the Y and Z axes is required.

As shown in FIGS. 5 and 6, a drive device 218 for moving the X-axis carriage 208 along the X-axis guide 206 is provided on the back surface 206a of the X-axis guide 206. The drive device 218 includes a drive pulley 213 located on one end side in the longitudinal direction of the X-axis guide 206 and a driven pulley 2 located on the other end side in the longitudinal direction of the X-axis guide 206.
14, a belt 215 hung between the driving pulley 213 and the driven pulley 214, and a motor 217 for rotationally driving the driving pulley 213. The belt 215 and the X-axis carriage 208 are connected by a connecting member 216, and the X-axis carriage 208 moves on the X-axis guide 206 in accordance with the rotation of the drive pulley 213.

The drive pulley 213 is rotatably supported by the support member 211, and the driven pulley 214 is supported by the support member 2.
It is rotatably supported by 12. Support member 21
1 is fixed to the back surface 206a of the X-axis guide 206, and the support member 211 and the support member 212 have a tension bar 219.
Are connected via The tension bar 219 ensures the rigidity of the belt 215.

In the above-described three-dimensional measuring apparatus, of the two supporting members 211 and 212, only the supporting member 211 on the drive pulley 213 side is fixed to the X-axis guide 206, and the tension bar 219 is fixed only by the supporting member 211. By adopting a structure for supporting the entire drive device 218 including the above, the problem of the drive device having a structure in which both support members 211 and 212 are respectively fixed to the X-axis guide 206, that is, the tension of the belt 215 causes the X-axis guide 206 to move. It is intended to eliminate the problem that the X-axis guide 206 loses its straightness by acting as a bending moment.

[0009]

However, the tension bar 219 has a strength such that the tension bar 219 itself is not deformed by the tension of the belt 215, and further, the tension of the belt 215 causes the pulleys 213, 21 to move.
The strength is required so that the interval of 4 does not change.

Further, as described above, in the drive device 218, only the support member 211 on the drive pulley 213 side is the X-axis guide 2.
Since it is connected to the X-axis guide 206, the connecting portion between the X-axis guide 206 and the drive device 218 is required to have sufficient strength to support the entire weight of the drive device 218 including the tension bar 219.

Therefore, there is a problem that the X-axis guide 206 is eventually deformed in the horizontal direction, the straightness of the X-axis guide 206 is lost, and the measurement accuracy is lowered.

The present invention has been made in view of such circumstances, and an object thereof is to provide a belt drive device capable of preventing the guide from being deformed by the tension of the belt and maintaining the straightness of the guide. .

[0013]

In order to solve the above-mentioned problems, the belt drive device according to the invention of claim 1 is provided with a guide,
The driving device includes a moving member that moves along the guide and a driving device that drives the moving member in a predetermined direction. The driving device includes a first pulley located on one end side of the guide and the other end of the guide. The second pulley located on the side, and the first pulley
And a belt connected between the second pulley and the moving member with a predetermined tension, and a belt connected to the moving member. In the belt drive device, the first pulley is rotatably attached to one end surface of the guide. The second pulley is rotatably supported, and the second pulley is rotatably supported on the other end surface of the guide, and at least a part of the guide is surrounded by the belt.

In the belt driving device according to the second aspect of the invention, the X guide is sandwiched by the belt in the horizontal direction or the vertical direction.

Further, in the belt driving device according to the third aspect of the present invention, the X guide has a hole extending in the longitudinal direction, and a part of the belt penetrates the hole.

[0016]

As described above, according to the belt drive device of the first aspect, the first pulley is rotatably supported on one end surface of the guide, and the second pulley is rotatable on the other end surface of the guide. Since at least a part of the guide is surrounded by the belt, the tension of the belt does not act on the guide as a bending moment in the horizontal direction but acts as a compressive force in the longitudinal direction of the guide. Horizontal deformation can be prevented.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing a belt driving device according to a first embodiment of the present invention, and FIG. 2 is a perspective view showing a three-dimensional measuring device equipped with the belt driving device of FIG.

As shown in FIG. 2, a Y-axis guide 3 is laid on the upper surface of the surface plate 2, and the upper ends of the columns 4 and 5 are connected by an X-axis guide (guide) 6 to form a gate shape. The structure 7 is placed. Air bearings (not shown) are respectively arranged between the column 4 and the surface plate 2, and between the column 5 and the Y-axis guide 3, and the gate-shaped structure 7 is guided by the Y-axis guide 3 to form the surface plate. 2 can be moved in the Y-axis direction.

An X-axis carriage (moving member) 8 is attached to the outer periphery of the X-axis guide 6 via an air bearing (not shown).
It is mounted so as to be movable in the axial direction. A Z-axis spindle 9 is supported on the X-axis carriage 8 via an air bearing (not shown) so as to be movable in the Z-axis direction.
A tracing stylus 10 is fixed to the lower end of the Z-axis spindle 9.

Both longitudinal end faces 6c, 6 of the X-axis guide 6
Support members 11 and 12 are fixed to d, and a drive pulley (first pulley) 13 and a driven pulley (second pulley) 14 are attached to the support members 11 and 12. It is rotatably supported. The rotation axes of the pulleys 13 and 14 are oriented in the vertical direction. A belt 15 is hung on each of the pulleys 13 and 14, and both ends of the belt 15 are connected to the connecting members 16a and 1a.
It is connected to the X-axis carriage 8 by 6b (FIG. 1). The belt 15 surrounds the entire X-axis carriage 8 from the horizontal direction as shown in FIG. 1, and the center line of the X-axis guide 6 and the center line of the belt 15 (virtual straight line connecting both ends in the longitudinal direction of the belt 15) are the same. Located in the vertical plane.

The drive pulley 13 has a reversible rotation motor 17
When the motor 17 rotates, the belt 15 hung on each pulley 13 and 14 moves and the belt 1
The X-axis carriage 8 moves in the X-axis direction in conjunction with the movement of 5.

A drive unit 18 is constituted by both the pulleys 13 and 14, the belt 15 and the motor 17.

When the driving device 18 is assembled to the X-axis guide 6, the initial tension of the belt 15 is set by adjusting the distance between the driving pulley 13 and the driven pulley 14, and the initial tension of the driving device 18 is set. The combined force having the center line (the center line of the belt 15) as the action line becomes the compressive force of the drive device 18. The drive pulley 13 and the driven pulley 14 have support members 11, 12
Since it is fixed to the X-axis guide 6 via, the compressive force acting on the center line of the drive device 18 acts on the X-axis guide 6.
Since the center line of the drive device 18 and the center line of the X-axis guide 6 coincide with each other, the force acting on the X-axis guide 6 is the compressive force of the X-axis guide 6. In general, when an equivalent force is applied to a rod-shaped structure having the same cross section and length, the compressed state is better between the compressed state applied on the center line of the cross section and the bending state applied as a bending moment off the center of the cross section. The amount of horizontal deformation is extremely small. Therefore, a small amount of horizontal deformation means that the straightness of the X-axis guide 6 does not change much.

When the X-axis carriage 8 is moved along the X-axis guide 6, the driving force corresponding to the inertial force of the X-axis carriage 8 acts to change the tension of the belt 15, but the tension changes. Is also a change in the compressive force applied to the X-axis guide 6, so that the straightness of the X-axis guide 6 is not lost.

Further, when the environmental temperature of the three-dimensional measuring device changes, the tension of the belt 15 changes due to the difference between the thermal expansion amount of the X-axis guide 6 and the thermal expansion amount of the belt 15. Since it is also the fluctuation of the compression force to 6,
The straightness of the X-axis guide 6 is not lost.

As described above, according to the three-dimensional measuring apparatus having the belt driving device of the first embodiment, the belt 15 surrounds the entire X-axis carriage 8 in the horizontal direction, and the center of the X-axis guide 6 is surrounded. Since the line and the center line of the belt 15 are aligned with each other, the tension of the belt 15 acts as a compressive force on the X-axis guide 6, and the straightness of the X-axis guide 6 is not lost, and high measurement accuracy can be obtained. To be

Further, it is possible to prevent the deformation of the X-axis guide 6 due to the difference in thermal expansion between the belt 15 and the X-axis guide 6.

As a modification of the first embodiment, a part of the belt 15 is penetrated into the internal space of the X-axis guide 6 so that the belt 15 surrounds part of the X-axis carriage 8 in the horizontal direction. May be.

FIG. 3 is a perspective view showing a belt driving device according to a second embodiment of the present invention, and FIG. 4 is a perspective view showing a three-dimensional measuring device equipped with the belt driving device of FIG.

The same parts as those of the first embodiment described above are designated by the same reference numerals and the description thereof will be omitted. In the above-described embodiment, the rotating shafts of the driving pulley 13 and the driven pulley 14 are arranged in the vertical direction, and both ends of the belt 15 are connected to the connecting members 16a,
16b is connected to the side surface 8a of the X-axis carriage 8,
Although the belt 15 surrounds the entire X-axis carriage 8 in the horizontal direction, in the second embodiment, the rotation axes of the drive pulley 23 and the driven pulley 24 are arranged in the horizontal direction, and the belt 25 is rotated. A part of the belt 25 is penetrated into the internal space of the X-axis guide 6, and both ends of the belt 25 are connected to the upper surface 8a of the X-axis carriage 8 by the connecting members 26a and 26b. I tried to be surrounded from the direction. X
The center line of the shaft guide 6 and the center line of the belt 25 are located in the same vertical plane.

In this embodiment, when the tension of the belt 25 acts on the X-axis guide 6 as a compressive force, the center line of the belt 15 is displaced from the center plane of the X-axis guide 6 in the height direction (Z direction). Therefore, the tension of the belt 15 acts as a bending moment in the height direction of the X-axis guide 6, but the cross section of the X-axis guide 6 is vertically long (long in the Z direction) and is hardly affected by the bending moment. . Also, the X-axis guide 6
By bringing the center line of the belt 15 closer to the upper surface of the, the influence of the bending moment acting on the upper surface of the X-axis guide 6 can be suppressed.

According to the three-dimensional measuring apparatus equipped with the belt driving device of the second embodiment, the same effect as that of the first embodiment can be obtained.

As a modification of the second embodiment, the belt 25 may surround the entire X-axis guide 6 in the vertical direction.

In each of the above-mentioned embodiments, belt-shaped belts 15 and 2
Although the case of using No. 5 has been described, an endless belt may be used instead of this.

[0036]

As described above, the first aspect of the present invention is as follows.
According to the belt drive device described in (1), the tension of the belt does not act as a bending moment in the horizontal direction with respect to the guide,
Since the guide acts as a compressive force in the longitudinal direction, the guide is hardly deformed in the horizontal direction, and the straightness of the guide is secured.

[Brief description of drawings]

FIG. 1 is a perspective view showing a belt drive device according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a three-dimensional measuring device including the belt driving device of FIG.

FIG. 3 is a perspective view showing a belt driving device according to a second embodiment of the present invention.

FIG. 4 is a perspective view of a three-dimensional measuring apparatus including the belt driving device of FIG.

FIG. 5 is a perspective view showing a conventional belt driving device.

FIG. 6 is a perspective view of a three-dimensional measuring apparatus including the belt driving device of FIG.

[Explanation of symbols]

 6 X-axis guide 8 X-axis carriage 13,23 Drive pulley 14,24 Driven pulley 15,25 Belt

Claims (3)

[Claims] 1. A guide, a moving member that moves along the guide, and a driving device that drives the moving member in a predetermined direction, wherein the driving device is located on one end side of the guide. It has a pulley, a second pulley located on the other end side of the guide, and a belt that is hung between the first and second pulleys with a predetermined tension and that is connected to the moving member. In the belt driving device, the first pulley is rotatably supported on one end surface of the guide, the second pulley is rotatably supported on the other end surface of the guide, and at least a part of the guide is A belt driving device, which is surrounded by the belt. 2. The belt driving device according to claim 1, wherein the X guide is sandwiched by the belt from a horizontal direction or a vertical direction. 3. The belt driving device according to claim 1, wherein the X guide has a hole extending in a longitudinal direction, and a part of the belt penetrates the hole.