JPH0214915Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention is suitable for use in fields that require ultra-precise processing and positioning with relatively small stroke linear motion, such as semiconductor manufacturing and information equipment. This relates to a drive device.

BACKGROUND ART FIG. 5 illustrates the most common structure of a linear motion device used in machine tools, etc.
is a movable part to which a nut 2 is fixed at the bottom; 3 is a guide part that slides and guides the movable part 1 in a straight line; 4 is a precision ball screw arranged parallel to the guide part 3 and screwed into the nut 2; 5 is a precision ball screw that is screwed into the nut 2; This is a rotary motor that rotates the precision ball screw 4. In this device, when the precision ball screw 4 is rotated by the rotary motor 5,
The rotational movement is converted into linear movement by the nut 2, and the movable part 1 moves linearly on the guide part 3 via the nut 2.

Problems to be solved by the invention The positioning accuracy in the above device is determined by the processing accuracy of the nut 2 and precision ball screw 4 above the guide part 3,
It is largely affected by the mounting accuracy and the size of the backlash. Incidentally, in recent years, in the field of ultra-precision machining and the like, there has been an increasing demand for linear motion devices capable of positioning with submicron accuracy with small strokes. However, in order to improve the positioning accuracy of the device with the above structure, it is necessary to improve the processing accuracy and installation accuracy of the nut 2 and precision ball screw 4, and to provide a preload mechanism to eliminate backlash. becomes complicated and expensive. In addition, in the above structure, even if the movable part 1 has a small stroke, the movable part 1, the guide part 3, the nut 2,
Since the precision ball screw 4, rotary motor 5, etc. are combined, there is a drawback that the entire device becomes large in size.

Therefore, recently, for example, in optical disc playback players, etc., a linear motion device with quick response and high precision has been adopted by combining a linear motor 11 and a linear guide section 12 as shown in FIG. Ta. However, this is also a combination of independent units of the linear motor 11 and the linear guide section 12, resulting in a relatively large device, and the entire device incorporating this has to be large as well. In FIG. 6, reference numeral 13 indicates an optical disk, 14 indicates a disk drive motor, 15 indicates an optical head, and 16 indicates a semiconductor laser.

Means for solving the problem This invention was proposed in view of the above problem, and the technical means for solving this problem is to The parts are connected with a magnetic material to form a Japanese-shaped base, and shaft support surfaces formed on the same plane are formed on both outer ends of the magnetic rods on both sides, and shaft support surfaces of the magnetic rod on one side are formed. A first guide shaft is stretched across and fixed between the surfaces, and a second guide shaft is stretched between the shaft support surfaces of the magnetic rod on the other side, and a guide block is movable along the shaft support surface. A movable table is elastically supported by a spring through the base plate, supported by linear motion bearings on both guide shafts, and is slidably mounted on the base plate. Permanent magnets are fixed on the inside so that the lines of magnetic force flow into the central magnetic rod at right angles, and are further fitted onto the lower surface of the movable table with a predetermined gap in the central magnetic rod of the base. and a moving coil is fixedly wound so as to be perpendicular to the lines of magnetic force of the permanent magnet.

Effect: According to the above technical means, the magnetic rod of the base serves as both the yoke of the linear motor and the guide of the moving table, so that the device has a compact and lightweight structure, and the above problems are solved.

Embodiment FIGS. 1 to 4 show an embodiment of the drive device according to this invention, in which two magnetic rods 21 are connected at both ends of three magnetic rods 22, 23, 24 arranged in parallel at predetermined intervals. The magnetic rods 22, 24 on both sides are provided with guide shafts 27, 28, respectively, on the outside, and the magnetic rods 22, 24 on both sides are connected with connecting rods 25, 26 to form a Japanese character shape. Permanent magnets 29 and 30 are fixed to the central magnetic rod 23 so that lines of magnetic force flow into it at right angles as shown by the arrows. guide shaft 27,
Reference numeral 28 denotes guide blocks 33, 34 and set screws 35, 36, which have obliquely notched end surfaces 33a, 34a on shaft support surfaces 31, 32 formed on the same plane at both outer ends of the magnetic rods 22, 24, respectively.
It is supported through: That is, the guide shafts 27 and 28 have both ends thereof connected to the shaft support surfaces 31 and 32.
At the top, small holes 22a bored in the magnetic rods 22, 24,
Screw receiver seats 31 are provided on the tip surfaces 33a, 34a of the guide blocks 33, 34, which are fitted into the guide blocks 24a with their tips protruding, and protrude from the ends of the shaft support surfaces 31, 32.
Set screws 35 and 36 screwed into a and 32a
It is supported by being pressed and fixed at the tip. In this case, the tip surfaces 33a, 3 of the guide blocks 33, 34
4a is notched diagonally, so the shaft support surface 31,
A component force is generated in the direction of 32, and the guide shafts 27 and 28 are also pressed and fixed to the shaft support surfaces 31 and 32. In addition, a coil spring 37 is compressed and interposed in the small hole 24a of the guide block 34, and the guide shaft 28 is attached to the shaft support surface 3.
It is elastically supported on 2. 38 is the base 21
A movable table disposed above, on the guide shafts 27 and 28 of the magnetic rods 22 and 24 on both sides of the base 21, for example, two on the guide shaft 27 and one on the guide shaft 28 side. It is movably held via a total of three guide linear motion bearings 39, 40, and 41. Reference numeral 42 denotes a moving coil formed by winding a conductive wire into a rectangular cylindrical shape, and its upper part is fixed via a bracket 43 to the lower surface of the moving table 38 movably mounted on the base 21, and its interior is A magnetic rod 23 at the center of the base 21 is disposed through the base 21 with a predetermined gap.

The above is the configuration of the drive device according to this invention, and next, the operation in the above configuration will be explained.

When a driving current is applied to the moving coil 42, the magnetic rod 23 at the center of the base 21 is connected between the permanent magnets 29 and 30.
A thrust is generated along the axis, which moves the movable coil 42 and moves the moving table 38 along the guide shafts 27 and 28 provided on the magnetic rods 22 and 24 on both sides of the base 21.
can be moved along. Further, by flowing the drive current in the opposite direction, the moving table 38 can be moved in the opposite direction. By attaching a position detector (not shown) to the movable table 38, the movable table 38 can be precisely positioned by controlling the drive current based on the position signal from this position detector.

Effects of the invention This invention has the advantage that the magnetic rods 22, 23, 2 of the base 21
Since 4 serves as the yoke of the linear motor and the guide of the moving table 38, the device has a compact and lightweight structure, and can easily be applied to systems that require particularly compact size. In addition, in general rolling bearings, a preload is applied to the bearing in order to improve accuracy and rigidity, but in the drive device of this invention, the guide shaft is attached via a guide block 34 that can slide along the shaft support surface. Linear motion bearings 39, 40,
Since preload is applied to 41, there is no need to provide any other complicated preload mechanism. Furthermore, in this type of drive, the guide shafts 27, 28 as well as the linear motion bearings 39, 4
Precise control of the parallelism of the 0.0 and 41 axes is difficult, and in order to achieve this, high precision machining and assembly are required. Guide shaft 28
Because they are elastically pressed and supported, defects in accuracy such as the parallelism of these axes can be absorbed, and even if there is a slight defect in accuracy, the system as a whole can maintain a predetermined accuracy.

[Brief explanation of drawings]

Fig. 1 is a perspective view of the drive device according to this invention, Fig. 2 is a bottom view thereof, Figs. 3 and 4 are cross-sectional views taken along line A-A and B-B in Fig. FIG. 5 is a schematic diagram illustrating a known drive device, and FIG. 6 is a perspective view of an optical disc reproducing player using a drive device that combines a conventional linear motor and a linear guide. 21... Base, 22, 23, 24... Magnetic rod,
25, 26... Connecting rod, 27, 28... Guide shaft,
29, 30... Permanent magnet, 31, 32... Shaft support surface, 33, 34... Guide block, 35, 36...
...Set Screw, 37...Coil Spring,
38...Moving table, 39, 40, 41...Guiding linear motion bearing, 42...Moving coil, 43...
...Bracket.

Claims (1)

[Scope of utility model registration request] The two ends of three magnetic rods arranged in parallel at predetermined intervals are connected with a magnetic material to form a Japanese-shaped base.
A shaft support surface molded to the same plane is formed on both outer ends of the magnetic rods on both sides, and a first guide shaft is fixed by extending across the shaft support surfaces of the magnetic rods on one side, and the other side is fixed. A second guide shaft is passed between the shaft support surfaces of the first magnetic rod, and is elastically supported by a spring through a guide block that can move along the shaft support surface, so that both guide shafts can be moved linearly. A movable table is slidably mounted on the base by supporting it via bearings, and permanent fixtures are installed inside the magnetic rods on both sides of the base so that the lines of magnetic force flow into the central magnetic rod at right angles. A magnet is fixedly installed on the lower surface of the moving table, and is inserted into the magnetic rod at the center of the base with a predetermined gap, and is wound so as to be orthogonal to the lines of magnetic force of the permanent magnet. A drive device characterized by a fixed moving coil.