JPH044171Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is configured such that a movable body that supports a probe is attached to a beam so as to be movable back and forth, and the movable body is driven to move the probe. This invention relates to improvements in driving devices for measuring instruments.

[Background technology and its problems]

A conventional structure of a drive device for a measuring machine in which a movable body supporting a measuring probe is mounted on a beam so as to be reciprocating and the movable body is driven to move the measuring probe will be described with reference to the drawings. The measuring machine is a three-dimensional measuring machine as shown in FIG. 4, and the driving device is a belt drive type as shown in FIG.

In FIG. 4, a surface plate 1 on which an object to be measured (not shown) is placed, a Y guide rail 2, and a surface plate 1.
A pair of Y sliders 3R, 3L that are movable in the Y-axis direction above, a pair of columns 4R, 4L erected on both sliders 3R, 3L, and an X beam 10 extending in the axial direction
An X slider 11 that is movable in the longitudinal direction on this beam 10, a Z column 5 that supports a Z spindle 6 attached to this X slider 11 so as to be movable in the Z axis direction, and a tip of the Z spindle 6. A three-dimensional measuring machine was constituted by a touch signal probe 7 (8 is a measuring element) supported on the side and an X slider driving means 20 which is a driving device. Note that the Y slider driving means and the Z spindle driving means are not shown.

Here, the X slider driving means 2 which is a driving device
0 is a drive pulley 2 rotated by a motor 21 attached to the upper end side of the support column 4R, as shown in FIG.
2. Support stand 1 attached to the upper end side of column 4L
3, a driven pulley 24 that can be rotated, and an endless belt 2 that extends between both pulleys 22 and 24.
3, and a part of the belt 23 is connected to the locking piece 1.
2 to the X slider 11.

Therefore, by rotating the motor 21,
The slider driving means 20 is driven, and the X slider 1
1 is moved on the X beam 10. Note that since the X slider 11 is supported by the X beam 10 using an air bearing, it slides smoothly. Then, the touch signal probe 7 attached to the Z spindle 6
When the probe 8 is moved in the axial direction and comes into contact with a measurement surface of an object to be measured (not shown), the coordinates of the measurement surface are taken into a measurement circuit (not shown). By sequentially repeating this operation and processing a plurality of coordinates obtained in a predetermined manner, it was possible to obtain the shape and dimensions of the object to be measured with a resolution of, for example, 1 μm. Note that the coordinates in the Y-axis direction and the Z-axis direction can be taken in by moving the Y sliders 3R, 3L and the Z spindle 6.

However, the conventional belt-driven three-dimensional measuring machine, that is, the driving device of the measuring machine, has the following problems.

That is, in order to drive the X slider driving means 20, which is a driving device, to move the probe 8 in the X-axis direction, it is necessary to move the X slider 11, which is a movable body, in the longitudinal direction of the X beam 10. Then, when the X beam 10 is viewed as a support rod at both ends, the X slider 11 becomes a moving load, so the load on the support columns 4R and 4L, which are the supporting ends thereof, changes moment by moment. Therefore, in such a measuring device, the movement of the X slider 11 induces bending or twisting in the structure. Specifically, since the Y sliders 3R and 3L are slidingly guided by the Y guide rail 2 and the surface plate 1 via air bearings, at least one of the columns is
Displaced in Y and Z directions. Due to its structure, this disturbs the orientation of the probe 8 with respect to the surface plate 1. This caused the problem that the measurement accuracy was worse than the designed value and high accuracy could not be guaranteed. This problem becomes more significant as the measuring device becomes larger (the X beam 10 becomes longer).

On the other hand, it is conceivable to collect displacement data of the probe 8 in advance based on bending, twisting, etc. of the structure due to the movement of the X slider 11, and perform program correction in the measurement circuit. However, the relationship between the movement of the X slider 11 and the position of the contact point 8 is delicate and complicated, and also differs depending on the model of the touch signal probe 7, etc. that includes the contact point 8, so it is difficult to uniquely determine the displacement data. has not been put into practical use because it is extremely difficult.

[Purpose of invention]

The present invention was developed in order to eliminate the above-mentioned conventional problems, and its purpose is to provide a driving device for a measuring machine that can maintain a constant attitude of the measuring head regardless of the movement of the movable body with respect to the beam. It's about doing.

[Means and actions for solving problems]

For this reason, the present invention provides a driving device for a measuring machine in which a movable body supporting a measuring element is attached to a beam so as to be movable back and forth, and the movable body is driven to move the measuring element. a balance weight capable of reciprocating in the longitudinal direction of the beam, and a balance weight that moves the balance weight in a direction opposite to the moving direction of the movable body as the feeding mechanism operates. The object is achieved by providing a reverse feed mechanism for moving the weight so that the weight loaded on both ends of the beam in the longitudinal direction is the same on the left and right sides.

Therefore, when the movable body is moved by the feed mechanism, the reverse feed mechanism moves the balance weight in the opposite (reverse) direction to the moving direction of the movable body, so that the movable body and the balance weight are aligned at the center in the longitudinal direction of the beam. Since it moves symmetrically around the center, the load on both ends of the beam is the same.

〔Example〕

An embodiment of a driving device for a measuring machine according to the present invention will be described in detail with reference to FIGS. 1 and 2.

The measuring machine in this embodiment is a three-dimensional measuring machine similar to the conventional three-dimensional measuring machine shown in FIG. 4 mentioned above. Therefore, the same parts will be given the same reference numerals and the explanation will be simplified or omitted.

The X slider driving means 20, which is a driving device, includes a motor 21, a driving pulley 22, and an endless belt 2.
3. (The belt in the present invention is a concept that includes chains, wires, etc.) It is composed of a driven pulley 24 and a balancer device 30.

In FIG. 1, a driving pulley 22 is connected to a motor 21 fixed to a column 4R, and a driven pulley 22 is connected to a motor 21 fixed to a support column 4R.
4 is rotatably provided on a support stand 13 attached to a support column 4L. Belt 23 connects both pulleys 2
2 and 24 with a predetermined tension, and a position 23A on the X beam 10 side, sandwiching the common axis of both pulleys 22 and 24, is connected to the X slider 11, which is a movable body, via a locking piece 12. At the same time, a position 23B on the opposite side thereof is connected to a balance weight 31, which will be described later. On the other hand, the balance device 30 consists of a guide rail 32 fixed to both supports 4R and 4L in parallel with the X beam 10, and a balance weight 31 equivalent to the weight of the X slider 11 including the weight of the Z column 5, Z spindle 6, etc. The balance weight 31 is configured to be slidable on the guide rail 32. Therefore, the motor 2 of the X slider driving means 20
1, the X slider 11 and balance weight 31 can move in opposite directions in the longitudinal direction of the X beam 10.

Here, a motor 21, both pulleys 22, 24 and a belt 2 which are part of the X slider driving means 20 are shown.
Reference numeral 3 constitutes a belt feeding means, and this belt feeding means has a feeding mechanism that reciprocates the X slider 11, which is a movable body, in the longitudinal direction of the X beam 10, and moves a balance weight 31 in the opposite direction to the moving direction of the X slider 11. It is said that it has an integrated configuration with a reverse feed mechanism that allows Therefore, the balance weight 31 is connected to the belt 23 so that when the movable X slider 11 is at the longitudinal center position of the X beam 10, the balance weight 31 is also at the longitudinal center position.

Next, the operation of this embodiment will be explained.

The measuring element 8 (see FIG. 4) is moved in the X-axis direction and brought into contact with the measuring surface of the object to be measured (not shown) by driving the motor 21 of the X slider driving means 20. When the motor 21 is driven, the drive pulley 22 rotates, and the endless belt 23 is driven by the driven pulley 2.
It can be moved through 4.

That is, when the feeding mechanism of the belt feeding means constituting a part of the X slider driving means 20, which is a driving device, moves the X slider 11, which is a movable body, to the right in FIG. is moved to the left in the same figure. Therefore, the loads on the left and right sides centered on the longitudinal center of the X beam 10 are equal, and the loads on both supports 4R and 4L can be kept unchanged.

In this way, the X coordinate of the measuring surface is read by a measuring circuit (not shown) from the amount of movement displacement of the measuring stylus 8 at the moment it comes into contact with the measuring surface. Repeat this procedure for the X-axis direction. Note that the Y-axis direction is changed by the movement of the Y sliders 3R and 3L, and the Z-axis direction is changed by the movement of the Y sliders 3R and 3L.
By raising and lowering the spindle 6, the above
Each coordinate can be read simultaneously with the axial direction.
By performing predetermined geometric calculations on the plurality of read coordinates (X, Y, and Z), the dimensions and shape of the object to be measured can be measured.

Therefore, according to this embodiment, since the feeding mechanism and the reverse feeding mechanism can move the X slider 11 and the balance weight 31, which are movable bodies, symmetrically about the center of the X beam 10, the X Since the load on both supports 4R and 4L that support the beam 10 at both ends can be kept unchanged, the posture of the probe 8 remains constant regardless of the movement of the movable body, and high precision measurement can be ensured.

Also, an X slider driving means 20 which is a driving device
Since it is of a belt-driven type, the structure is simple and symmetrical movement of the movable body and the balance weight 31 can be reliably achieved.

Furthermore, since the structure does not deform due to the movement of the movable body as in the prior art, the entire measuring device can be made smaller and lighter without changing the effective measurement range.

In the above embodiment, the feed mechanism and the reverse feed mechanism of the drive device are belt-driven, but the present invention is not limited to this, and a screw feed type etc. may also be used. It can also be used as a. In this sense, the structure of the balance weight 31 of the balance device 30 can also be used as a balance weight depending on the configuration of the feeding mechanism of the movable body. Note that the respective weights of the movable body and balance weight and the loads on both ends of the beam due to these do not mean that they are completely the same. The point is that the present invention aims to eliminate the conventional drawback of large fluctuations due to the movement of the movable body, so the present invention includes small imbalances that do not substantially affect measurement accuracy. That is to say.

Although the disclosure has been made regarding belt driving of the X slider 11, the present invention is also applicable to belt driving of the Y slider 3R and Z spindle 6, and is not limited to three-dimensional measuring machines, but also to two-dimensional measuring machines and the like.

[Effect of idea]

The present invention can ensure high precision measurement because the posture of the probe can be maintained constant regardless of the movement of the movable body.

[Brief explanation of drawings]

Fig. 1 is a perspective view of essential parts showing an embodiment of a driving device for a measuring machine according to the present invention, Fig. 2 is an explanatory diagram of the same operation, and Figs. 3 and 4 show a driving device for a conventional measuring machine. , FIG. 3 is a perspective view of the main part, and FIG. 4 is a diagram showing the overall configuration of the measuring machine. 8... Measuring head, 10... X beam, 11... X slider as a movable body, 20...
... motor, 22 ... drive pulley, 23 ... belt, 24 ... driven pulley, 30 ... balance device which is part of the X slider driving means, 31 ... balance weight.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A driving device for a measuring machine in which a movable body that supports a measuring point is attached to a beam so as to be movable back and forth, and the movable body is driven to move the measuring point. A feeding mechanism for reciprocating the movable body in the longitudinal direction of the beam; a balance weight capable of reciprocating in the longitudinal direction of the beam; and a movement direction of the movable body as the feeding mechanism operates. and a reverse feed mechanism for moving the balance weight in the opposite direction, and is configured so that the weight loaded on both ends of the beam in the longitudinal direction is the same on the left and right sides. (2) In claim 1 of the utility model registration claim, the feeding mechanism and the reverse feeding mechanism include an endless belt extending around an integral pulley and a motor that rotates one of the pulleys. A driving device for a measuring machine, wherein the movable body and the balance weight are respectively locked to the belt at positions on opposite sides of an axis connecting both pulleys.