JPH0557558A - Mobile guide - Google Patents

Abstract

PURPOSE:To keep a stage in a steady temperature as a whole by cooling any heat being produced in a coil in a driving means, preventing a thrust drop from occurring, and controlling a temperature in this driving means to be constant in a highly accurate manner, in a mobile guide apparatus which shifts a conveyed work up to a specified position on a fixed bed. CONSTITUTION:A magnetic fluid 70 is filled up in a gap between stators 61, 65 and needles 61, 63, installing two circulating routes 28, 30, where this magnetic fluid 70 is circulated, and a cooling means, setting a temperature of the magnetic fluid to a constant one, is set up in the midway, through which magnetic grains of the magnetic fluid 70 receives a Lorentz's force by an electric current flowing in the stators 62, 65, thereby making the magnetic fluid itself forcibly circulate around. Moreover, since the magnetic fluid 70 is controlled to be a steady temperature, it cools any heat to be produced in a coil in a driving means, preventing a thrust drop from occurring, and it controls a temperature in the driving means to be constant in a highly accurate manner, thus the whole stage can be kept in a steady temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving guide device for a moving body in a semiconductor manufacturing apparatus, a precision machine tool or the like.

[0002]

2. Description of the Related Art Conventionally, in a movement guide device for moving a conveyed object to a predetermined position, a stage capable of reciprocating on a fixed bed, for example, in directions of two orthogonal axes, a guide for holding these stages, and a drive for driving the stages. It is configured by means. Generally, a ball screw and a step motor, for example, are used as the driving means. However, since the resonance frequency of the ball screw is within the frequency band of the positioning control, it may be difficult to perform highly accurate positioning control. The movement guidance device used for is adopted. The linear motor is a driving unit that obtains thrust by using a magnet for the mover (hereinafter, the mover is a magnet) and a coil for the stator (hereinafter, the stator is a coil), and applying a current to the coil. However, Joule heat may be generated by the current flowing through the coil and the thrust force may be reduced. Therefore, when the magnetic fluid flows into the gap between the magnet and the coil, the magnetic fluid reduces the magnetic resistance between the gaps, and the current used can be reduced when the same thrust is obtained as compared with the case where the magnetic fluid is not used. The Joule heat generated is also reduced. Further, with respect to the generated heat, the coil is directly cooled by the base fluid of the magnetic fluid to prevent the thrust from being lowered, and the entire stage can be maintained at a steady temperature to enable highly accurate position movement control. FIG. 2 is a diagram showing the configuration of a movement guide device using a linear motor. On the fixed bed 37, the first stage 31 is held and guided by the guides 32a and 32b, and reciprocates in the X ₁ and X ₂ directions by the first driving means 33. The second stage 34 on the first stage 31 is held and guided by the guides 35a and 35b, and reciprocates in the Y ₁ and Y ₂ directions by the second driving means 36. Therefore, the second stage 34 on which the conveyed object is placed moves in the X ₁ , X ₂ , Y ₁ , Y ₂ direction by the first stage 31 and itself to move the conveyed object to a predetermined position. be able to. The driving means 33 and 36 show the structure of a linear motor, and the stator (coil) 5
2, 55, mover (permanent magnet) 50, 53, and yoke 5
X ₁ as examples made Figure 3 from 1,54 and a magnetic fluid 56,
The cross section of the X ₂ direction driving means is shown.

[0003]

However, in such a structure, when the first stage 31 and the second stage 34 are moved to move the conveyed object to a predetermined position, the stators 52 and 55 have no problem. Joule heat is generated due to the flow of current. The generated heat reduces the efficiency of the driving means and reduces thrust. When the magnetic fluid reduces the magnetic resistance between the mover and the stator to obtain the same thrust, the operating current can be reduced and the Joule heat generated can also be reduced. However, for the heat generated, the coil is directly cooled by the magnetic fluid base fluid, but since the heat capacity of the base fluid is fixed, it is not possible to sufficiently cool the heat generated in the coil. There is a problem in that heat causes a temperature distribution that causes deformation of thermal stress, and this temperature distribution adversely affects the mechanical accuracy of the stages, guides, and the like, and a predetermined performance cannot be obtained.

The present invention solves the above-mentioned problems of the prior art by reducing the generation of Joule heat generated in the mover of the driving means of the stage to prevent the thrust from decreasing and cooling the generated heat using the cooling means. It is an object of the present invention to provide a movement guide device capable of performing highly accurate position movement control by keeping the entire stage at a steady temperature by performing the operation.

[0005]

In order to achieve this object, the movement guide device of the present invention is a movement guide device for moving an article to a predetermined position on a fixed bed, which is on the fixed bed. A first guide fixed parallel to the direction, a first stage capable of linear reciprocating motion on the first guide in the first direction, and the first direction on the first stage A second guide fixed in parallel with a second direction perpendicular to the second guide and a second guide which is on the second guide and is capable of linear reciprocating motion in the second direction and on which an article to be conveyed is placed. A stage and first drive means on the fixed bed for driving the first stage in the first direction and a stage on the first stage for driving the second stage in the second direction A second drive means for The means comprises a stator having one of a coil and a magnet, and a mover having another one of the coil and the magnet that moves linearly along the stator, which is different from the stator. A first circulation path in which the magnetic fluid filled between the movers and the magnetic fluid in the first driving means circulate and a second circulation path in which the magnetic fluid in the second driving means circulates. A first cooling means for cooling the magnetic fluid in the circulation path and the first circulation path and a second cooling means for cooling the magnetic fluid in the second circulation path are provided. is doing.

[0006]

With this structure, the magnetic fluid reduces the magnetic resistance between the mover and the stator, and when the same thrust is obtained as compared with the case where the magnetic fluid is not used, the operating current can be reduced and the Joule heat generated. Will also decrease. Further, with respect to the generated heat, the coil is directly cooled by the base fluid of the magnetic fluid to prevent the thrust from being lowered, and the Lorentz force acts on the magnetic particles of the magnetic fluid due to the current flowing in the coil to circulate the magnetic fluid itself (for example, The magnetic fluid is forcibly circulated without a circulation pump, and the temperature of the magnetic fluid is stabilized by providing a cooling means in the middle of the circulation path of the magnetic fluid.
Furthermore, it is possible to maintain a stable temperature for the entire stage and perform highly accurate position movement control.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A movement guide device according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing the overall configuration of a movement guide device of the present invention.

[0008] The first stage 21 on the fixed bed 20 is linearly reciprocated in the direction of the X _1, X ₂ by the holding and guided first drive means 23 by the first guide 22a, 22b. In addition, the second stage 24 has a second guide 25.
Second driving means 2 held and guided by a and 25b
6 reciprocates in the directions of Y ₁ and Y ₂ . Therefore, the second stage 24 on which the transported object is placed has X ₁ , X ₂ ,
It is possible to move in the Y ₁ and Y ₂ directions to move the conveyed product to a predetermined position. First and second drive means 23 and 26
Shows the configuration of the linear motor, and the stators (for example, coils) 62 and 65 and the movers (for example, permanent magnets) 61 and 63 are shown.
And yokes 60 and 64. Further, as shown in FIG. 3, a magnetic fluid 70 based on, for example, kerosene is filled between the movers 61 and 63 and the stators 63 and 65. The magnetic fluid 70 has a first circulation path 28 and a second circulation path 30.
It is designed to go back through the inside and back again. A first cooling means 27 and a second cooling means are installed in the first circulation path 28 and the second circulation path 30, respectively. The operation of the movement guide device configured as described above will be described below with reference to FIG.

First, an electric current is passed through the stators 62 and 65 of the first drive means 23 and the second drive means 26 in order to convey the article on the second stage 24 to a predetermined position. Then, the Lorentz force acts on the magnetic particles of the magnetic fluid 70 in the gap between the stators 62 and 65 and the movers 61 and 63 by the current flowing through the stators 62 and 65, and the magnetic particles forcibly move the base fluid. As a result, the magnetic fluid is circulated in the circulation path 2.
It circulates in 8, 30. During the process, the magnetic fluid 70 is cooled by the first cooling means 27 and the second cooling means 29 and is controlled to a constant temperature with high accuracy, and the first circulation path 28, again.
Returning from the second circulation path 30 to the first drive means 23, 26.

As described above, the Lorentz force is exerted on the magnetic particles of the magnetic fluid to forcibly circulate the magnetic fluid, a circulation path is provided, and cooling means for setting the temperature of the magnetic fluid to a constant temperature is provided in the middle of the circulation path. It is possible to cool the heat generated in the coil inside the driving means, prevent the thrust from decreasing, and control the inside of the driving means to a constant temperature with high accuracy to keep the entire stage at a steady temperature.

In the embodiment, the first guide 22
Although the a and 22b and the second guides 25a and 25b have a V-V groove structure, the first guides 22a and 22b and the second guides 25a and 25b may have a V groove-flat groove structure.

In this embodiment, the magnetic fluid 70 uses kerosene as a base fluid, but the magnetic fluid 70 may use a non-conductive fluid as a base fluid.

[0013]

As described above, according to the present invention, the magnetic fluid is filled in the gap of the stator of the mover to provide a circulation path for the magnetic fluid to make one round, and the temperature of the magnetic fluid is kept at a constant temperature in the middle of the circulation path. By installing the cooling means, the heat generated in the stator (coil) inside the driving means is cooled to prevent thrust reduction, and the inside of the driving means is controlled to a constant temperature with high accuracy to keep the entire stage steady. Can be kept at a proper temperature.

[Brief description of drawings]

FIG. 1 is a perspective view of a movement guide device according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a conventional movement guide device.

FIG. 3 is a detailed view of a conventional movement guide device.

[Explanation of symbols]

 20 Fixed Bed 21 First Stage 22a, 22b First Guide 23 First Driving Means 24 Second Stage 25a, 25b Second Guide 26 Second Driving Means 27 First Cooling Means 28 First Circulation Path 29 Second cooling means 30 Second circulation path 60,64 Yoke 61,63 Moving element (for example, permanent magnet) 62,65 Stator (for example, coil) 70 Magnetic fluid

Claims (1)

[Claims] 1. A moving guide device for moving a conveyed object to a predetermined position on a fixed bed, the first guide fixed on the fixed bed in parallel with a first direction, and the first guide. A first stage that is capable of linear reciprocating motion in the first direction, and a second guide that is on the first stage and is fixed in parallel to a second direction that is orthogonal to the first direction. The second stage, which is on the second guide, is capable of linear reciprocating motion in the second direction, and on which the transported object is placed, and the first stage, which is on the fixed bed, are the first stage The first and second driving means on the first stage and the second driving means for driving the second stage in the second direction. Is a stator having one of a coil and a magnet, and the stator And a magnetic fluid filled between the stator and the mover, and a first mover in the first drive means. A first circulation path in which the magnetic fluid circulates, a second circulation path in which the magnetic fluid circulates in the second drive means, and the magnetic fluid in the middle of the first circulation path. And a second cooling means for cooling the magnetic fluid, which is located in the middle of the second circulation path.