JPH01129751A - Positioning device - Google Patents

Abstract

PURPOSE:To promote the high speed of a device by providing a coil mounted to a positioning table, permanent magnet provided facing to this coil in a bottom plate part of a fixed device provided in the positioning table and cross roller bearings between a mounting part of the positioning table and the fixed device. CONSTITUTION:A positioning table 1 provides mounting parts 9, 9 to be hung in a moving direction, winding a coil 3 on a bobbin 15. A fixed device 5 is constituted of a bottom plate part 11 and side plate parts 13, 13, providing the positioning table 1 in the side plate parts 13, 13 through cross roller bearings 27. A permanent magnet 7 is placed facing to the coil 3 on the bottom plate part 11. Further the bottom plate part 11 provides in its one side a photo sensor 19 to be parallelly arranged with the permanent magnet 7. A center pole 7 uses a magnetic material forming a magnetic circuit for magnetic fluxes from the coil 3 and from the permanent magnet 7 to pass through, and a linear scale 29 is mounted to the side plate part 13 detecting a relative position of the positioning table 1 for the fixed device 5.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates generally to positioning devices, and more particularly to, for example, positioning devices.
The present invention relates to a positioning device equipped with a positioning table that can be suitably applied as an X-Y table or an l-axis (X) table in an x-Y table.

To U of - Conventional positioning devices include devices that drive the positioning table using a rotary motor, devices that drive the positioning table using piezoelectric/electrostrictive actuators, and devices that use a linear stepping motor as the drive source for the positioning table. There were various types of positioning devices, such as devices that Among the various types of positioning devices mentioned above, the type of device that uses a rotary motor as a drive source to drive a positioning table converts the rotational driving force of the rotary motor into linear motion through a mechanism such as a ball screw, for example. There is a method in which a positioning table is reciprocated in a linear direction, and it is possible to increase the positioning accuracy of the positioning table relative to a fixing device that movably supports the positioning table to about several meters. However, when the rotation system of the rotary motor reaches a critical speed, lateral vibration occurs due to reaching the critical speed, so there is a problem in that it is difficult to increase the speed. In addition, in a type of device that drives a positioning table using a piezoelectric/electrostrictive actuator as a drive source, it is possible to position the positioning table relative to a fixing device with very high precision, but the movable stroke is extremely small. ,parable,
Even if a so-called displacement magnification mechanism is added to the positioning device, it is impossible to increase the extremely small movable stroke to a size that is sufficiently practical. Furthermore, in a type of device that drives a positioning table using a linear stepping motor as a drive source, although it has the advantage of being able to introduce an open-loop control system that can be configured at low cost, There was a problem that positioning could not be performed with high precision.

Therefore, the present invention was devised to improve the above-mentioned problems, and its purpose is to achieve even higher speed and more accurate positioning of the positioning table relative to the fixing device. It is an object of the present invention to provide a positioning device that can perform a sufficient movable stroke.

The above objects are achieved by a positioning device according to the present invention. In summary, the present invention provides a positioning table in which mounting portions are formed on both sides in the direction of movement, a coil attached below the positioning table, and a positioning table capable of reciprocating substantially linearly. a fixing device having both side plate portions provided to support the positioning table and a bottom plate portion connected to the both side plate portions; and a fixing device provided on the bottom plate portion of the fixing device facing the coil. The positioning device is characterized in that it comprises a permanent magnet, and a cross roller bearing provided between a mounting portion of the positioning table and both side plate portions of the fixing device.

! 1. Hereinafter, embodiments according to the present invention will be described with reference to the drawings.

1, 2 and 3 show a positioning device according to a first embodiment of the present invention. A positioning device according to a first embodiment of the present invention is shown in FIGS. 1, 2 and 3. As is clear with reference to FIG. 3, the coil 3 mainly attached to the lower part of the positioning table 1 and the positioning table 1, and the fixing device that supports the positioning table 1 so as to be able to reciprocate in a substantially straight direction. 5 and is disposed on the fixing device 5 in such a manner as to face the coil 3. The structure includes a permanent magnet 7. The details of the above-mentioned configuration will be further explained as follows. That is, the positioning table 1 has mounting parts 9, 9 vertically installed on both sides of the positioning table 1 in the direction of movement thereof, and the coil 3 is attached to the positioning table 1 with its hollow part along the direction of movement of the positioning table 1. The coil bobbin 15 attached to the center of the bottom is wound with an epoxy adhesive or a heat-resistant adhesive such as acrylic or polyimide adhesive.

The coil 3 is provided with a detection signal that, when it is detected that the temperature of the coil 3 has reached a predetermined value (for example, 135° C.), causes the power supply to the coil 3 to be cut off and a predetermined alarm to be issued. In this embodiment, the coil bobbin 15 is provided with a coil temperature sensor (not shown) for outputting a coil temperature, and is made of a glass epoxy material or a hard plastic material such as ABS, PPS, or polycarbonate. has been done. Furthermore, in the moving direction of the bottom of the positioning table l mentioned above, an interrupter 21 passing through the guide groove of the photosensor 19, which will be described later, is involved, and the photosensor 19
and interrupter 21 constitute photo-interrupter means for restricting the positioning table 1 from moving outside a preset movement range.

The fixed type g! ! 5 is arranged in a line on both longitudinal sides of the bottom plate part 11 with a bottom plate part ll having a substantially strip shape so that the cross-sectional shape taken in the longitudinal direction of the housing 215 has a substantially U-shape. The main constituent elements are side plate portions 13.13 having a substantially concave length in the longitudinal direction of the bottom plate portion 11, which are connected to each other by provided screw members, and further, both ends in the longitudinal direction of the bottom plate portion 11. As is apparent from FIGS. 1 and 3, end plates 23, 23 are assembled therein. The side plate portion 13.13 is provided to support the positioning table l via a cross roller bearing 27 in the present invention, so that the positioning table l can reciprocate approximately linearly. In this embodiment, a material made of aluminum is used in order to easily radiate heat generated in the coil 3 to the outside when power is supplied to the coil 3. Bottom plate part 1
A strip-shaped permanent magnet 7 having a length substantially equal to the length of the bottom plate portion 11 in the longitudinal direction is placed in a substantially central portion of the magnet 1, facing the coil 3. . The permanent magnet 7 is made of rare earth magnet material, samarium cobalt magnet material, neodymium iron boron magnet material, ferrite magnet material,
A magnet made of one of plastic magnet materials is used. By using the above types of magnetic materials for the permanent magnet 7,
Permanent magnet7. A voice coil type linear DC motor constituted by a fixing device 2t5, a coil 3, etc. is designed to provide a large thrust. Furthermore, on the negative side of the bottom plate portion 11 in the longitudinal direction, there is a photosensor 19 whose length in the longitudinal direction is approximately the same as the length in the longitudinal direction of the permanent magnet 7. The above-mentioned interrupter 21 faces inside the guide groove which is arranged in parallel and is formed along the longitudinal direction of the photosensor 19 . Approximately at the center of the internal space defined by the bottom plate part 11, both side plate parts 13.13, and both end plates 23.23 of the fixing device 5, one end part is attached to one end plate 23, It extends along the moving direction of the positioning table l through the hollow part of the coil pobbin 15, and the other end is connected to the other end plate 2.
A center ball 17 reaching 3 is provided. A magnetic material is used for the center ball 17, and a magnetic circuit is formed through which the magnetic flux from the coil 3 side and the magnetic flux from the permanent magnet 7 side, which are generated when an excitation current is supplied to the coil 3, pass. It looks like this. Of the side plate parts 13.13, a linear scale 29 having a length in the longitudinal direction of the fixing device 5 and a substantially concave length is attached to the side plate part 13 on the side separated from the photointerrupter 19. It is being The linear scale 29 is for detecting the relative position of the positioning table 1 with respect to the fixing device 5, and in this embodiment, a linear scale with a resolution of 1 μm and an accuracy of ±21 Lm is employed. In the space defined by the side plate portions 13.13 constituting the fixing device 5 and the mounting portions 9.9 provided on both sides of the positioning table 1 in the moving direction, bearing means, In the present invention, cross roller bearings 27.27 are provided, and by providing these cross roller bearings 27.27, side plate portion 13.
The sliding surface faces the mounting portion 9.9 of 13 and the side plate portion 13.13 of the mounting portion 9.9! This improves the durability of the dynamic surface and maintains high rigidity.

In this way, by adopting the cross roller bearings 27, 27, even if a large load is applied to the positioning table l, it will not be distorted and accurate mounting accuracy can be maintained.
It also allows for long strokes while maintaining a low coefficient of friction.

According to the positioning device configured as described above, since a voice coil type linear DC motor is used, linear driving force can be directly obtained, and the configuration can be extremely simplified and compactly designed. Since there is almost no backlash or play that occurs when using rotary motors, gears, or pole screws, mechanical errors are reduced. or,
Since a rare earth magnet material or the like is used for the permanent magnet 7, it is possible to increase the thrust of the voice coil type linear DC motor. In addition, the coil pobin 15 is made of glass epoxy resin, so it has good insulation, and the coil 3 is bonded to the coil pobin 15 using an epoxy adhesive, so it has good heat resistance and rigidity. It is. In addition, when the coil temperature sensor detects that the temperature of the coil 3 has reached a predetermined value (135°C) or higher, the supply of excitation current to the coil 3 is cut off, so that the coil 3 is not overloaded. It is possible to prevent this from happening. Furthermore, since it was decided to attach a linear scale 29 with easy disassembly IILm and accuracy of ±2#Lm to the side plate part 13, the positioning table l
It has become possible to perform positioning relative to the fixing device 5 with high precision.

! FIG. 7S4 shows a positioning device according to a second embodiment of the invention.0 A positioning device according to a second embodiment of the invention is as apparent with reference to FIG.

The positioning device according to the first embodiment of the present invention is characterized in that a ventilation means (fan unit) 31 is detachably provided on one end plate 23 of the positioning device according to the first embodiment of the present invention. The fan unit 31 described above has a ventilation hole 33 and a fan unit) 3.
1 is detachably attached to the end plate 23. A fan drive connector 35 is detachably attached to the end plate 23. By attaching the fan unit 31 in this manner, the positioning table l passes through the through hole (not shown) formed in the end plate 23.
, both side plate parts 13.13, end plate 23.23 and bottom plate part 11
The fixed bag M of the positioning table 1 is supplied with cold air to further improve the cooling effect on the coil 3 and prevent the occurrence of mechanical distortion due to heat.
The relative position relative to 5 can now be determined with higher precision. The fan unit 31 can be selected from various shapes and sizes or cooling capacities depending on the size of the positioning device and the amount of heat generated by the coil 3.

FIG. 5 shows a positioning device according to a third embodiment of the present invention. As is clear with reference to FIG. 2
The positioning device according to the embodiment is characterized in that handles 37, 37, 37, 37, which can be attached and detached, are provided on both side plate portions 13.13 constituting the fixed bag 215.

In this way, both side plate portions 13 configuring the fixing device 5 .
13, a handle 37 that can be attached and detached freely;
The reason for providing 37, 37.37 is as described below. That is, in a precise positioning device that requires precision in microns, the accuracy of mounting the first position determining table 1 to the fixing device 5 is very important. Therefore, in order to ensure sufficient mounting accuracy of the positioning table 1 to the fixing device 5, and also to achieve high rigidity, it is possible to sufficiently withstand even when a maximum load of about 15 kg is applied to the positioning table l. In addition, a method of providing cross roller bearings 27, 27 as described above was proposed. However, when transporting and moving the positioning device 1, it is very difficult to carry it because there are no protrusions on the fixing device 5 side in order to make the entire device more compact. As a result, since the entire device is very heavy, an unexpected load is applied to the mounting portion 9 of the positioning table 1, which may adversely affect the mounting accuracy.

Therefore, in order to solve such problems, the above-mentioned proposals have been made.

FIG. 6 shows a positioning device according to a fourth embodiment of the present invention. A positioning device according to a fourth embodiment of the present invention is as apparent with reference to FIG.

This embodiment is characterized in that the positioning table 1 and fixing device 5 of the positioning device according to each of the embodiments described above are locked and fixed by a screw member 39. in this way,
The positioning table 1 and the center ball 17 constituting the fixed bag fi5 are fixed with a screw member 39 at a position away from the position of the coil 3, so that the positioning table 1 and the fixed bag M5 are locked and fixed. The reason is that, as explained in the third embodiment, when the positioning device is transported or moved, the positioning table 1 and the fixed bag M5 collide, causing an unexpected load on the bearing surfaces of the cross roller bearings 27 and 27. This is to prevent this from having an adverse effect on the mounting accuracy between the positioning table l and the fixing device 5.

FIG. 7 shows positioning according to a fifth embodiment of the invention! The positioning device according to the fifth embodiment of the present invention indicates the A position.
As is clear with reference to FIG. 7, the positioning table main body l, the mounting portions 9.9 formed on both sides of the positioning table main body l in the moving direction, and the mounting portions 9.9 on the side plate portions 13.13. Regarding one corresponding part, at least the attachment part 9 formed on the moving direction side of the positioning table main body l is configured as a separate member from the positioning table main body l so that it can be freely attached to and detached from the positioning table main body l, The portion of the side plate l corresponding to the attachment portion 9 is also characterized in that it is constituted by a side plate attachment portion 13a that is a separate member from the side plate main body 13. The reason why one positioning table main body l and one mounting part 9 are constructed from separate members is as follows.

That is, in order to mount the positioning table l to the fixing device 5 with high precision, it is necessary to improve the mounting precision of the cross roller bearing 27 that is mounted in the space defined by the mounting portion 9 and the side plate portion 13. Must be,
In order to install the cross roller bearing 27 with high precision in this way, the surface of the mounting portion 9 on the side facing the side plate portion 13 and the surface of the side plate portion 13 on the side facing the mounting portion 9 must be processed with high precision at the same time. It becomes necessary to carry out

However, if the positioning table main body l and the mounting part 9 are made of the same material as in the conventional positioning table l, it is difficult to perform high-precision machining as described above, and the time spent on machining becomes long. Moreover, there was a problem of poor yield. Therefore, in order to solve this problem, at least the mounting part 9 on the moving direction side of the positioning table l is constructed as a separate member from the positioning table main body 1, and a side plate part corresponding to the mounting part 9 is constructed. The part 13 is also configured with a side plate attachment part 13a that is a separate member from the side plate main body 13, and after processing the attachment part 9 and the side plate attachment part 13a with the same precision, respectively. The attachment portion 9 is attached to the positioning table main body l, and the side plate attachment portion 13a is attached to the side plate 13 using screw members or the like.

FIG. 8 shows a positioning device according to a sixth embodiment of the present invention. A positioning device according to a sixth embodiment of the present invention is as apparent with reference to FIG.

The present invention is characterized in that a copper tube 41 is fitted onto the outer periphery of the center ball 17 constituting the fixing device ai5 of the positioning device according to each of the embodiments described above. The reason why the outer periphery of the center ball 17 is surrounded by the copper tube 41 in this way is that the center ball 17 is normally used.

Since it is made of iron material, when the center ball 17 is passed through the hollow part of the coil bobbin 15 around which the coil 3 is wound, the inductance of the coil 3 becomes very large. There was a problem with the delay. Therefore, as in this embodiment, by surrounding the outer periphery of the center ball 17 with the copper tube 41, the inductance of the coil 3 can be reduced.
is made smaller than when it exists alone, thereby improving electrical rises such as frequency response. Note that the effect of reducing the inductance of the coil 3 described above is more effective as the electrical resistance of the copper tube 41 is lower, so materials used for the copper tube 41 include pure copper, electrolytic copper, tough pitch copper, and oxygen-free copper. Copper etc. are preferred.

9 and 1θ show a positioning device according to a seventh embodiment of the present invention. A positioning device according to a seventh embodiment of the present invention has side plate portions 13.1 constituting the fixing device 5.
3 is made of iron material or super duralumin material from which strain has been sufficiently removed from the normal state, and both side plate portions 13.
13 and the bottom plate part 11, screw members 43.43 are arranged in two rows to lock and fix the both side plate parts 13.13 to the bottom plate part 11. The reason why the fixing device 5 is configured as described above is that when a heavy object is placed on the positioning table l, the side plate parts 13.13 supporting the positioning table l are conventionally made of aluminum material. Moreover, there is a risk of distortion due to the above-mentioned load, which not only reduces the positioning accuracy of the relative position of the positioning table l with respect to the fixing device 2t5, but also causes a risk of yawing and pitching phenomena. Furthermore, since only one row of screw members 43 were provided for connecting and fixing the above-mentioned side plate portions 13.13 to the bottom plate portion 11, a force applied in a direction perpendicular to the moving direction of the positioning table l was provided. Therefore, if a device with such a configuration is changed from the 1-axis specification (X) to the 2-axis specification (x-y), there is a risk that the positioning accuracy will decrease significantly. There was also. Therefore, the above proposal was made with the aim of solving such problems.

By configuring the positioning device as described above, it has also become possible to significantly reduce magnetic leakage compared to conventional devices. Note that the screw members 43.43 may be used to lock and fix the side plate portions 13.13 to the bottom plate portion 11 in such a manner that they are substantially orthogonal to each other, as shown in FIG. 1θ.

[1] As explained above, according to the present invention, a positioning table with higher speed and higher precision can be achieved. It is possible to provide a positioning device that can perform relative positioning with respect to the fixing device and can take a sufficient movable stroke.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view of a positioning device according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view of the positioning device according to the first embodiment of the present invention, viewed from the longitudinal direction. FIG. 3 is a partially cutaway side view of the positioning device according to the first embodiment of the invention. FIG. 4 is a perspective view showing a positioning device according to a second embodiment of the invention. FIG. 5 is a perspective view showing a positioning device according to a third embodiment of the present invention. FIG. 6 is a sectional view of the positioning device according to the fourth embodiment of the present invention, viewed from the longitudinal direction. FIG. 7 is a partial vertical sectional view showing a positioning device according to a fifth embodiment of the present invention. FIG. 8 is a sectional view of the positioning device according to the sixth embodiment of the present invention, viewed from the longitudinal direction. FIG. 9 is a sectional view of the positioning device according to the seventh embodiment of the present invention, viewed from the longitudinal direction. FIG. io is a partial vertical sectional view showing a positioning device according to a seventh embodiment of the present invention. lSecond position lDetermining table 3: Coil 5: Fixing device 7: Permanent magnet 9: Mounting part 11: Bottom plate part 13.13: Side plate part ゛15: Coil bobbin 27.27: Cross roller bearing Fig. 1 Fig. 2 Fig. 4 Figure 6 Figure 7 Figure 10

Claims (1)

[Claims] 1) A positioning table having attachment parts formed on both sides in the direction of movement, a coil attached below the positioning table, and the positioning table capable of reciprocating substantially linearly. a fixing device having both side plate portions provided to support the positioning table and a bottom plate portion connected to the both side plate portions; and a fixing device provided on the bottom plate portion of the fixing device facing the coil. A positioning device comprising: a permanent magnet; and a cross roller bearing provided between a mounting portion of the positioning table and both side plate portions of the fixing device. 2) The positioning device according to claim 1, wherein the permanent magnet is made of a rare earth magnet material, a samarium-cobalt magnet material, a neodymium iron boron magnet material, a ferrite magnet material, or a plastic magnet material. 3) The coil is attached to a bobbin attached to the bottom of the positioning table with the hollow part along the moving direction of the positioning table using a heat-resistant adhesive such as epoxy adhesive, acrylic adhesive, or polyimide adhesive. The coil is wound, and when it is detected that the temperature of the coil has reached a predetermined value, a detection signal is output that cuts off the power supply to the coil and triggers a predetermined alarm. A coil temperature detection means is provided to
The bobbin is made of glass eboshi material, ABS, PPS
3. A positioning device according to claim 1 or 2, constructed of a hard plastic material such as polycarbonate. 4) Both side plate parts of the fixing device are formed of an aluminum material, iron material, or super duralumin material, and the both side plate parts and the bottom plate part are screw members arranged in two rows. A positioning device according to any one of claims 1 to 3, which is connected and fixed by. 5) A blowing means is detachably provided at one end in the longitudinal direction of the fixing device, and a means for detecting the relative position of the positioning table with respect to the fixing device is provided on one of both side plate portions of the fixing device. A linear scale with a resolution of approximately 1 μm and an accuracy of ±2 μm is provided, and a hollow portion of the bobbin is provided approximately in the center of the internal space defined by the bottom plate portion and both side plate portions of the fixing device. A center ball is provided extending through the center ball along the moving direction of the positioning table, and a copper tube is fitted to the outer periphery of the center ball, and further to the outer periphery of the fixing device. The positioning device according to any one of claims 1 to 4, wherein the positioning device is provided with a plurality of handles. 6) Attachment portions formed on both sides of the positioning table body in the direction of movement of the positioning table body and portions of the both side plate portions corresponding to the attachment portions are at least attachment portions formed on the side in the direction of movement of the positioning table body. The part is constructed of a separate member from the positioning table body so that it can be attached to and detached from the positioning table body, and the part of the side plate corresponding to the attachment part is also detachably attached to the side plate body. The positioning device according to any one of claims 1 to 5, wherein the positioning device is constituted by a side plate mounting portion that is a separate member from the side plate main body. 7) The positioning table is configured to be locked and fixed to the fixing device by a screw member, and a bottom part of the positioning table has a mechanism for moving the positioning table out of a preset movement range. The positioning device according to any one of claims 1 to 6, further comprising a photointerrupter means for restricting the movement of the object. 8) Claims 1 to 7, wherein a voice coil type linear DC motor is constituted by a coil attached to the bottom of the positioning table, the fixing device, and a permanent magnet attached to the fixing device. The positioning device described in any of the above.