JPH05123932A - Guide device - Google Patents

Abstract

PURPOSE:To improve the rigidity of a direct-acting guide without spoiling its guide characteristic in a device for guiding a moving body such as the column and saddle of a machine tool. CONSTITUTION:A direct-acting guide 4 is formed of a rail 5 and a nut 6. Plural balls 7 to be engaged with the rail 5 are supported on the inner side face of the nut 6. Plural nuts 6 are disposed at the nut support part of a moving body 3, and a block 9 is fixed to a part of these nuts 6. The moving body 3 is provided with a piezoelectric actuator 11 in the position corresponding to this nut 6. At the time of machining, the piezoelectric actuator 11 presses the nut 6 to the support face 12 of the rail 5 through the block 9. Pre-load between the rail 5 and nut 6 is thereby increased so as to improve the rigidity of the direct-acting guide 4. Since pressing force acts upon the support face 12 of the rail 5, there is no fear of deformation being generated to the rail 5 or nut 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION This invention relates to a machine tool column,
The present invention relates to a guide device that guides a moving body such as a saddle by a linear motion guide.

[0002]

2. Description of the Related Art In recent years, linear motion guides have been widely used as machine tools have become faster. Compared to the sliding guide type, the linear motion guide has smaller sliding resistance and excellent responsiveness at high speed feed, but its rigidity is insufficient and cracks occur when the workpiece is heavily cut. Accuracy may decrease. In view of this point, conventionally, there has been proposed a technique of adjusting the preload between the rail and the nut of the linear guide to improve the rigidity of the linear guide during machining. For example, in the guide device disclosed in Japanese Patent Laid-Open No. 63-150128, a nut is provided with a pair of ball support pieces projecting from both left and right sides of the rail, and an arm is arranged outside each ball support piece and at the same time an inner side is provided. The ball that engages with the rail is supported, and during processing, the actuator drives the arm to press the ball support piece toward the rail side, and the rail is sandwiched by the ball, so that the preload of the linear guide can be set high. ing.

[0003]

However, according to the conventional guide device, since the actuator presses the ball support piece toward both the left and right side surfaces of the rail, when the preload is increased, the ball support is supported by the pressing force of the actuator. There is a problem in that the piece is deformed, the original guide characteristics of the linear motion guide are impaired, and the processing accuracy is adversely affected. Then, the subject of this invention is providing the guide apparatus which can improve the rigidity of a linear guide at the time of processing, without impairing the guide characteristic of a linear guide.

[0004]

In order to solve the above problems, the present invention provides a guide device for guiding a moving body by means of a linear guide having a rail and a nut movably supported by the rail. A means of arranging a plurality of nuts on the moving body and providing an actuator for pressing a part of the nuts on the support surface of the rail is adopted.

[0005]

According to the guide device of the present invention, the preload corresponding to the pressing force of the actuator acts between the rail of the linear motion guide and the nut. That is, during high-speed feeding of the moving body,
The actuator does not operate, the preload at the time of assembling acts on the linear guide, and the moving body is guided with good responsiveness, thereby extending the life of the linear guide. On the other hand, at the time of processing, the pressing force of the actuator is set strongly, the preload of the linear motion guide is increased, the rigidity thereof is increased, and cracking is prevented, thereby improving the processing accuracy. In this case, since the actuator presses a part of the plurality of nuts, a phase difference occurs between the nuts, and a preload based on this phase difference is applied to the linear guide. Therefore, it is not necessary to provide actuators for all the nuts, and the entire device can be simply configured with a small number of parts. Further, since the pressing force of the actuator acts on the supporting surface of the rail, there is no possibility that the nut or the rail will be deformed by the pressing force, and the guide characteristic of the linear guide is always maintained good.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to the drawings. 1 is a sectional view of a guide device showing an embodiment of the present invention, FIG. 2 is a side view of FIG. 1, FIG. 3 is a schematic plan view of the entire device, and FIGS. Figure 1
As shown in FIG. 1, the guide device 1 of this embodiment is provided between the base 2 and the moving body 3 of the machine tool. Guidance device 1
Is provided with a linear motion guide 4, and the linear motion guide 4 is composed of a rail 5 extending in the drive direction of the moving body 3 (direction D-E in FIG. 3) and a nut 6 movably supported by the rail 5. Has been done. A plurality of balls 7 that engage with the rails 5 are rotatably supported on the inner surface of the nut 6.

As shown in FIG. 3, the movable body 3 is provided with a plurality of nut support portions 8 and each of the nut support portions 8 has a nut 6.
Are provided in plurality. As shown in FIG.
A block 9 is fixed to a part of the nuts 6b of the nuts 6, and the block 9 is constrained by the recess guide surface 10 of the moving body 3 in the driving direction. And
A piezoelectric actuator 11 is housed in the moving body 3 at a position corresponding to the nut 6b, and when a voltage is applied,
The block 9 is moved along the recess guide surface 10 to press the ball 7 of the nut 6b against the support surface 12 of the rail 5. The nut support portions 8 have the same structure, and the nuts 6b are partially attached to the piezoelectric actuator 1.
1 is provided.

Next, the operation of the guide device constructed as described above will be described. In this embodiment, the preload corresponding to the pressing force of the piezoelectric actuator 11 is applied to the linear guide 4
It acts between the rail 5 and the nut 6. That is, when the moving body 3 is fed at a high speed, the piezoelectric actuator 11 is not operated, the preload at the time of assembly acts on the linear guide 4, and the moving body 3 is guided responsively under a slight sliding resistance. Was
This prevents wear of each part of the linear motion guide 4,
The life can be extended.

On the other hand, during processing, the piezoelectric actuator 1
1 is applied with a predetermined voltage, the pressing force is set strongly, the preload of the linear guide 4 is increased, the rigidity thereof is increased, and cracking is prevented, thereby improving the processing accuracy. In this case, since the piezoelectric actuator 11 presses a part of the nuts 6b among the plurality of nuts 6, a phase difference occurs between the nuts 6, and a preload based on this phase difference is applied to the linear guide 4.

That is, in the nut 6b, as shown in FIG. 4, the pressing force of the piezoelectric actuator 11 acts in the B direction, whereby the balls 7a and 7b are pressed against the support surfaces 12a and 12b of the rail 5. On the other hand, nut 6
In the nuts 6a and 6c (see FIG. 2) adjacent to b, as shown in FIG. 5, the pressing force of the piezoelectric actuator 11 acts in the C direction, so that the balls 7c and 7d move to the support surface 12c of the rail 5, 12d is pressed. The pressed portion is shown by hatching in FIGS. 4 and 5. Therefore, with the operation of one piezoelectric actuator 11, each nut 6
Pre-load is applied to the linear motion guide 4 in a state where the rail 5 is sandwiched by the plurality of nuts 6 with a phase difference between them. Therefore, it is not necessary to provide the piezoelectric actuators 11 on all the nuts 6, and the entire device can be easily configured with a small number of parts. The pressing force of the piezoelectric actuator 11 is the rail 5
Since it acts on the support surface 12, the nut 6 or the rail 5 is not likely to be deformed by the pressing force, and the guide characteristics of the linear guide 4 can always be kept good.

The present invention is not limited to the above-described embodiment. For example, a hydraulic actuator or a pneumatic actuator may be used instead of the piezoelectric actuator 11, or the shape of the support surface 12 of the rail 5 may be appropriately modified. For example, the shape and configuration of each part can be arbitrarily modified and embodied without departing from the spirit of the present invention.

[0012]

As described above in detail, according to the present invention, the plurality of nuts are arranged on the moving body and the actuator for pressing a part of the nuts against the supporting surface of the rail is provided. The excellent effect that the rigidity of the linear guide can be improved during processing without impairing the guide characteristics of the dynamic guide.

[Brief description of drawings]

FIG. 1 is a sectional view of a guide device according to an embodiment of the present invention.

FIG. 2 is a side view of FIG.

3 is a schematic plan view showing the entire guide device of FIG. 1. FIG.

FIG. 4 is an explanatory view of the action of the nut at the central portion in FIG.

5 is an explanatory view of the action of the left and right nuts in FIG. 2. FIG.

[Explanation of symbols]

1 ... Guide device, 2 ... Base, 3 ... Mobile unit, 4 ...
Linear guides, 5 ・ ・ rails, 6 ・ ・ nuts, 7 ・ ・ balls, 8 ・ ・ nut support parts, 9 ・ ・ blocks, 10 ・ ・ recess guide faces, 11 ・ ・ piezoelectric actuators, 12 ・ ・ support faces.

Claims (1)

[Claims] 1. A guide device for guiding a moving body by a linear guide provided with a rail and a nut movably supported by the rail, wherein a plurality of nuts are arranged on the moving body and a part of the nuts is provided. A guide device comprising an actuator for pressing a supporting surface of a rail.