JPS614476A - Positioning device - Google Patents

Abstract

PURPOSE:To obtain an inexpensive device which can position without contact by disposing the primary side coils of two linear induction motors at both front and rear sides of the positioning point of a moving article as a center, and providing a magnetic circuit for generating a DC magnetic field at the positioning point. CONSTITUTION:The secondary side conductor 2 of a linear induction motor is secured to a moving article 3 guided by a linear guide 1. Two primary side coils 5a, 5b for generating thrusts toward the positioning points with the positioning point of the article 3 as a center are symmetrically disposed, and a magnetic circuit 5 for generating a DC magnetic field is mounted so that a magnetic flux is perpendicularly crossed to the secondary side conductor 2 at the positioning point. Thus, the primary side coils 4a, 4b are economically used together with driving and positioning the article 3, and smoothly without contact.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to a positioning device, and particularly to a positioning device using a linear induction motor.

[Technological environment]

In recent years, in the semiconductor industry, there has been an increasing need for non-contact drive and non-contact positioning due to the aversion to dust generated from production equipment and transport equipment. In addition to the above non-light width, non-contact drive and positioning
O linear induction motors, which are superior in high speed, maintainability, and economy, and are increasingly being used in various industrial fields, relatively meet the above requirements because their driving force is non-contact.

[Prior art]

In a conventional positioning device using a linear induction motor, a primary coil is provided on the ground side of a positioning point, and a moving body to which a secondary conductor is fixed is accelerated or decelerated to move between positioning points. In order to finally position and fix the object, a mechanical means such as a stopper is used to contact the moving object.

This mechanical positioning method causes contact parts to wear out and
There was a drawback that dust was generated. Furthermore, mechanical positioning methods are usually performed using a simple mechanism such as using an air cylinder, which has the disadvantage that excessive force is applied to the movable body during positioning, and a large impact is applied to the guide mechanism.

In particular, when air levitation or magnetic levitation type non-contact guidance is used for guidance, mechanical positioning has the disadvantage that levitation control is complicated and expensive.

An example of non-contact positioning is to fix a magnetic body on the moving side and install an electromagnet on the stationary side for positioning, but when positioning, adsorption force acts on the movable body, making it difficult to use air levitation or magnetic levitation. When non-contact guidance is used, it is necessary to increase the floating rigidity, which has the disadvantage of being complicated and expensive.

[Purpose of the invention]

An object of the present invention is to provide an inexpensive and clean positioning device that can position two linear induction motors without contact by providing a DC magnetic field orthogonal to the secondary conductor between the primary coils. It's about doing.

[Structure of the invention]

The positioning device of the present invention includes a linear guide and the above-mentioned ?
. Line chi 1. Nigauchi wa, = ya induction and -2゜2
Next group.

A moving body to which a conductor is fixed, primary coils of two linear induction motors arranged symmetrically in a moving direction centering on a positioning point of the moving body and generating thrust toward the positioning point, and at the positioning point. and a magnetic circuit that generates a DC magnetic field such that magnetic flux is orthogonal to the secondary conductor.

[Explanation of Examples]

Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of the present invention.

The positioning device shown in FIG. 1 consists of a linear guide 1, a movable side 3 to which a secondary conductor 2 made of non-magnetic material such as aluminum is fixed, two primary coils 4, and a magnetic circuit 5. CIIfi is included.

Next, the operation will be explained.

When the movable body 3 is guided by the linear guide 1 and enters an area near the positioning point, a force proportional to the distance between the positioning point and the center line of the secondary conductor 2 acts toward the positioning point. However, due to the magnetic circuit 5, a force proportional to the speed of the moving body 3 and in the direction of the direction of movement acts on the secondary conductor 2 in accordance with Fleming's left-hand rule.

Therefore, if the speed of the moving body 3 near the positioning point is reduced, even if it temporarily overruns the positioning point, it will gradually attenuate and be positioned.

In order to drive the moving body 3 to move between a large number of positioning points, the primary coils 4a, 4b and the magnetic circuit 5 of the embodiment are provided at each positioning point, and when accelerating, the connection of the primary coils is changed. By switching to generate thrust in the direction of movement, and for deceleration to generate thrust in the opposite direction to the movement direction, and performing the positioning operation described above, movement and positioning between multiple points is possible. It is.

FIG. 2 is a diagram showing the thrust exerted on the movable body 3 by plowing.

The thrust shown in FIG. 2 changes depending on the position of the center line P of the secondary conductor 2, and the thrust force shown in FIG. l
Assuming that the amount of ll is proportional to the thrust, the result will be as shown in Figure 2. When the center line P is at point A, the secondary conductor 2 overlaps the entire length of the primary coil 4a, so a large amount of thrust generated by the primary coil 4a acts on the secondary conductor 2. B
When the primary coil 4a is at the positioning point, the overlapping amount of the primary coil 4a is larger than that of the primary coil 4b, and the total thrust acting on the secondary coil 2 is the thrust acting toward the positioning point, and the thrust is proportional to the distance from the positioning point. At point 0, the amount of rotation of the primary coils 4a and 4b is the same, so the thrust forces cancel each other out and do not work. At points D and E, a thrust is exerted toward the positioning point in the same manner as described above.

FIG. 3(a) and the 31st column (b) are block diagrams showing that the system of this example is stable.

In both FIG. 3(a) and FIG. 3(b), it is assumed that the frictional force of the guide is negligibly small.

FIG. 3(a) shows only the primary coils 4a and 4b and no magnetic circuit 5, and FIG. 3(b) shows a case where there is a magnetic circuit 5, as in the embodiment of the present invention. It is a block diagram.

The block diagram in FIG. 3(a) shows the total mass of the moving body 3 including the secondary conductor 2 (the sum of the inversely proportional element 6, the secondary integral element 7, and the primary coils 4a and 4b). The system shown in FIG. 3 fa) is unstable because it is a quadratic system without damping. In other words, there is no friction or active braking force, so there is no reduction in oscillation.

The block diagram in Figure 3tb) consists of an element 6 that is inversely proportional to the total mass of the moving body 3 including the secondary conductor 2, a first-order integral element 9, and a first-order (11u coil 4a + 4b). It is composed of an element 8 indicating the total output coefficient of , and an element 10 indicating the output coefficient generated by the magnetic circuit 5.

In the system shown in FIG. 3(b), the braking force is proportional to the speed and acts in the opposite direction to the moving direction, so the primary coils 4a, 4b
If the output coefficient 8 is appropriately selected, the system is stable.

For example, even if there is an overrun at the positioning point, it will be returned to the positioning point again, and the next overrun amount will be f
It becomes smaller and attenuates compared to the previous overrun.

〔Effect of the invention〕

The positioning device of the present invention is of a non-contact type, has no fitting parts, has no wear parts, is easy to maintain, is reliable, and has the effect of not generating dust. The moat does not require any complicated mechanism and is inexpensive and economical. Furthermore, if the connections of the primary coils 5a and 5b shown in the present invention are switched and directed toward the moving direction, the moving body 3 can be driven to another positioning point, and the primary coil 5 can be used for positioning and moving. It can be shared with the drive and has the advantage of being economical. In addition, since the brake is applied in proportion to the speed, positioning can be performed more smoothly and with less icing than mechanical positioning.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an example of an actual cannon of the present invention, Fig. 2 is an explanatory drawing showing the thrust force exerted by one movement on the moving body 3, and Fig. 3 shows the stability of the system of the embodiment shown in Fig. 1. FIG. 1... Linear guide, 2... Secondary conductor, 3... Moving body, 4... Primary side E, 5... ...Magnetic circuit, 〉6...Element inversely proportional to the total fat of the moving object, 7...Second-order integral element, Death...Indicates the output coefficient of the primary coil. element,
9...Primary integral element, 10...Element indicating the output coefficient of the magnetic circuit. Agent Patent Attorney Ni Uchihara. ＼＋／ No2 closed

Claims (1)

[Claims] a linear guide, a moving body guided by the linear guide to which a secondary conductor of a linear induction motor is fixed, and arranged symmetrically in a moving direction with a positioning point of the moving body as a center to generate thrust toward the positioning point. A positioning device comprising: primary coils of two linear induction motors; and a magnetic circuit that generates a DC magnetic field such that magnetic flux is orthogonal to the secondary conductor at the positioning point.