JP2000278930A - Feed mechanism using linear motor - Google Patents

Abstract

(57) [Summary] In a dust cover of a linear motor driving device, when a linear motor moves at high speed, air enters and exits from a small gap of the dust cover, and dust in the air,
In particular, a linear motor driving device capable of preventing iron powder from being attracted to a magnet portion of a linear motor is provided. A feed mechanism using a linear motor including a linear guide rail (2) that linearly moves a moving table (7) using linear motors (5) and (6) as a drive source, and a bellows cover (8) covering at least the linear motors (5) and (6).
A magnet 11 for adsorbing dust entering from a gap formed by the bellows cover 8 was installed around the gap. This allows
The iron powder contained immediately before entering the inside of the bellows cover 8 is attracted to the magnet 11 to prevent the iron powder from adhering to the armature and the magnet of the linear motor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a feed mechanism using a linear motor which is a part of a feed mechanism of a machine tool.

[0002]

2. Description of the Related Art FIG. 4 is a perspective view showing an example of a feed mechanism using a conventional linear motor. The feed mechanism using a linear motor shown in FIG. 4 is arranged at a position where chips generated by cutting work are not directly applied, and only a single-axis mechanical portion is extracted from the feed mechanism structure of a machine tool employing a bellows cover. FIG. 2 is an external view in which a part of a bellows cover is cut so that an internal structure can be easily understood. FIG.
5 is a sectional view of a feed mechanism using the linear motor shown in FIG.

The conventional feed mechanism using a linear motor includes a stopper 1 for regulating the stroke of a moving table 7, a linear guide rail 2, a linear guide 3, a position detector 4 for detecting the position of the moving table 7, a linear motor, Stator (magnet) 5, linear motor mover (armature) 6, moving table 7, bellows cover 8 covering front and rear of moving table 7 (front bellows cover 8a, rear bellows cover 8b), bellows It is composed of a cover guide 9, a fixing screw 15, and a base 14 of a feed mechanism.
The bellows cover 8 is provided to protect the armature and the magnet portion of the linear motor from dust and chips existing in the outside air. In this conventional example, the bellows cover 8 also serves to protect the linear guide portion. .

[0004]

In the prior art shown in FIGS. 4 and 5, the moving table 7 has a bellows cover 8b.
When moving from the side stroke end toward the bellows cover 8a, the air pressure in the bellows cover 8a rises due to the movement of the moving table 7, and the air passes through the gap under the moving table 7 and the air pressure falls, so that the bellows cover 8b is reduced.
Move to the side. When the moving table 7 moves in the opposite direction, the air inside the bellows cover 8 also flows in the opposite direction, and when the moving table 7 is fed at a low speed, the inflow and outflow of outside air can be ignored.

However, as the moving speed of the moving table 7 increases, the air resistance when passing through the gap under the moving table 7 cannot be ignored, and the pressure inside the bellows cover 8 changes, and the left and right linear guides are changed. Bellows covers 8a, 8b existing along rail 2
Air enters and exits through the gap between the base and the base 14. Specifically, when the moving table 7 moves from the stroke end on the bellows cover 8b side to the bellows cover 8a side, the inside air flows out from the bellows cover 8a side, and the outside air flows in from the bellows cover 8b side. The amount of inflow and outflow depends on the ratio of the total area of the gap under the moving table 7 and the ratio of the total volume of air moving in the bellows cover. In this way, the inflow and outflow of outside air occur more remarkably, and dust, particularly iron powder, enters the bellows cover 8, and the following problem occurs.

When dust and chips enter the dust-proof cover of the linear motor, iron powder is particularly attracted to the armature and the magnet of the linear motor and adheres and accumulates. When the linear motor finally moves, the iron powder adhering to the armature and magnets seizes into the gap between the armature and magnet, causing a large load on the linear guide and significantly shortening the guide life. Since the iron powder directly touches the armature winding, there is a problem that the protective film of the winding is damaged, causing a short circuit between the windings and deteriorating the insulation resistance between the grounds.

On the other hand, to solve this problem, a technique of drawing air into the dustproof cover and keeping the inside of the cover always higher than the outside air pressure is used. In this case, however, the pressure inside the cover due to the high speed and high acceleration / deceleration of the linear motor is used. It is necessary to secure an air flow rate sufficient to absorb the change, and a plurality of pipes must be installed along the linear guide to reduce the air inflow resistance. Furthermore, in this case, the internal pressure rises during high-speed, high-acceleration / deceleration feed, and the bellows cover is rolled up. There was a problem that the use of the installation must be used.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a feed mechanism using a linear motor comprising a guide means for linearly moving a moving body using a linear motor as a drive source and a dustproof cover for covering at least the linear motor portion. The above object of the present invention is attained by providing a magnet around the gap, which attracts iron powder entering through the gap formed by the dustproof cover. Due to these, the feed mechanism using the linear motor according to the present invention has a magnet installed around the gap between the dust-proof cover of the linear motor, so that when the outside air enters the inside of the dust-proof cover, there is a problem that the iron powder becomes a problem. Can be attracted to the magnet, and the iron powder can be prevented from adhering and depositing on the armature and the magnet of the linear motor.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an external view showing a feed mechanism using a linear motor according to an embodiment of the present invention, in which a part of a bellows cover is cut so that an internal structure can be easily understood. FIG. 2 is a cross-sectional view showing a feed mechanism using the linear motor shown in FIG. 1, and FIG. 3 is an explanatory diagram showing an outside air intrusion path of the feed mechanism using the linear motor shown in FIG.

A feed mechanism using the present linear motor includes a stopper 1 for regulating the stroke of the moving table 7, a linear guide rail 2, a linear guide 3, a position detector 4 for detecting the position of the table, and a linear motor stator (magnet). ) 5.
It comprises a linear motor mover (armature) 6, a moving table 7, a bellows cover 8 (a front bellows cover 8 a, a rear bellows cover 8 b) and a bellows cover guide 9 covering the front and rear of the moving table 7. Further, in the feed mechanism using this linear motor, although only the near side is seen in FIG. 1, two grooves 10 are provided along two linear guide rails 2 as shown in the sectional view of FIG. And two fixing screws 13
And is fixed to the base 14 of the feed mechanism.

As described in the section of the prior art, the outside air enters through the gap between the bellows covers 8a and 8b and the base 14. In the present embodiment, as shown in FIGS. Groove 1 processed along rail 2
A magnet mounting plate 12 having a magnet 11 mounted thereon is installed at 0, and iron powder can be adsorbed by the magnet 11 and removed immediately before the outside air enters the inside of the bellows cover 8 as shown in FIG. In addition, a long hole is machined in the magnet mounting plate 12,
By loosening the mounting screw 13, the magnet mounting plate 12
It can be easily slid and removed, and when it is fixed directly below the bellows covers 8a, 8b,
The structure is useful for checking the amount of iron powder adsorbed on the surface.

[0012]

As described above, according to the present invention, in a feed mechanism using a linear motor, when the moving body of the linear motor moves, air enters and exits from a small gap in the structure of the dustproof cover, and the outside world Problem of the life of the linear guide caused by intrusion of dust existing in the air, and short-circuiting between the windings of the linear motor caused by iron powder in the dust being attracted to the magnet part of the linear motor And the problem of deterioration of the insulation resistance between the grounds can be solved. Further, according to the present invention, by providing the magnet mounting plate that can be slid and removed as described above, the amount of iron powder adsorbed on the magnet by sliding the magnet mounting plate can be easily confirmed, and the magnet There is an effect that the magnet can be easily cleaned by removing the mounting plate.

[Brief description of the drawings]

FIG. 1 is an external view showing a feed mechanism using a linear motor according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a feed mechanism using the linear motor shown in FIG.

FIG. 3 is an explanatory diagram showing a flow of outside air entering a feed mechanism using the linear motor shown in FIG.

FIG. 4 is an external view showing a feed mechanism using a conventional linear motor.

5 is a sectional view showing a feed mechanism using the linear motor shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stopper 2 Linear guide rail 3 Linear guide 4 Position detector 5 Linear motor stator (magnet) 6 Linear motor mover (armature) 7 Moving table 8 Bellows cover 8a Front bellows cover 8b Rear bellows cover 9 Bellows cover guide 10 Groove 11 Magnet 12 Magnet mounting plate 13 Fixing screw 14 Base 15 Fixing screw

Claims (1)

[Claims] 1. A feed mechanism using a linear motor comprising a guide means for linearly moving a moving body using a linear motor as a drive source, and a dustproof cover for covering at least the linear motor portion, wherein the feed mechanism enters through a gap formed by the dustproof cover. A feed mechanism using a linear motor, wherein a magnet for adsorbing dust is provided around the gap.